subsea - page 4

BOP HydraulicControl

Systems

Subsea Engineers Handbook Section 4

In-Spec Inc. 1999 BOP Hydraulic Control Systems

Table Of ContentsSection 4

Page

1. General Description of Hydraulic Control System 1

2. Operation of a Surface Accumulator 2

3. Controlling the BOP Stack 3

4. Subsea BOP Control System Diagram 4

5. Stepping Through the Subsea Hydraulic Control System5

a. Hydraulic Power Unit and Surface Control Manifold 5b. Hydraulic Hose Bundle and Storage Reel 8c. Control Pods 10d. BOP Remote Control Panels 17e. Diverter Control 20

6. Hydrostatic effects on Subsea Accumulator Bottles 22

7. API and MMS System Sizing, Response Guidelines 23

8. BOP Response Times 24

9. Hydraulic Systems Flow 26

a. Main Hydraulic Supply 26b. Regulator Pilot Circuits 28c. Operation of a 3 Position Function 30d. Operation of a 2 Position Function 32e. Operation of a Straight thru Function 34

10. Typical Hydrulic Power Unit Schematic 36

11. Typical Manifold Schematic 37

12. Typical Pod Schematic 38

13. Typical Stack Schematic 39


In-Spec Inc. 1999 BOP Hydraulic Control Systems

14. Hydraulic Symbols 40

15. Fitting Information 43

16. Troubleshooting: Pressure Losses 47

17. Troubleshooting: SPM Failure 53

18. Troubleshooting: Leaks and Malfunctions 56

19. Operation of the Electrical Portion of the System 66


In-Spec Inc. 1999 1 BOP Hydraulic Control Systems

General Description of a Hydraulic Control System

1) 5 Main Components of the Surface Hydraulic Power Unit (HPU)



Operation of the Surface Accumulator Bottle

Atmospheric PressureThe accumulator bottle has a bladder of tough, synthetic rubber that is shaped like atapered cigar. It has this shape when there is no pressure on it. The tapered shapeis important because it gives a pushing or squeeze action when fluid is discharging.The bladder completely separates the nitrogen precharge from the hydraulic fluid.This prevents the gas from mixing with the hydraulic fluid.

Pre-ChargedThe bottle is precharged with nitrogen through a valve at the top of the bottle.Nitrogen is used due to its relative inertness and availability. At the bottom is theport through which hydraulic fluid is pumped. The fluid also leaves the bottle fromthis port. A poppet valve closes the port when the bladder pushes against it. The1,000 psi of nitrogen precharge pushes the elastic bladder to the bottom of the bottleand closes the poppet valve preventing the bladder from being pushed out of theport.

Initial ChargeNext, hydraulic fluid is pumped into the bottle, and the 1,200-psi minimum pressureIs reached quickly.

Fully ChargedAt far right, the bottle is fully charged with fluid to 3,000-psi working pressure. Theadditional fluid pumped into the bottle raises the pressure from the 1,200 psi initialcharge to the 3,000 psi fully charged state. As fluid is used from the bottle thepressure will drop to 1,200 psi. The fluid delivered by the bottle during this processis called the usable fluid available from the bottle.



Controlling the BOP Stack

To be useful we must control an entire BOP stack. The system power supply must beobtained from more than 1 source so an air powered pump is added to the system.

Of course our stack will contain more than 1 ram so we have added more preventersand a control valve for them. The same regulator is used for all the ram preventers andis called the manifold regulator.

Since the annular BOP may require a different pressure from the rams, a separateregulator is added to supply hydraulic fluid to it.

R Annular Regulator

3000 PSI

Bladder

N 2N 2

Float

Air Pump

1. Alternate Power Source2. Operate more than one BOP3. Operate Annular with its own

regulator

R



Stepping Through the Subsea Hydraulic Control System

1) Hydraulic Power Unit and Surface Control ManifoldThe hydraulic power unit is usually mounted integrally with the surface controlmanifold. It supplies the hydraulic fluid, a mixture of water soluble oil andwater, to the control system. The unit contains a reservoir section whichincludes two reservoirs and a hydraulic fluid mixing system, a pump sectionwhich includes both air and electric operated pumps, and an accumulatorsection. The reservoir section has two reservoirs, one for water soluble oil, andone for the mixed hydraulic fluid.

The water soluble oil reservoir has typically a 100 gallon capacity. The mixedfluid reservoir contains at least enough fluid to fully charge the systemaccumulators from their precharge pressure to the maximum system workingpressure. Both reservoirs are equipped with graduated sight glasses and low-level alarms.

The fluid mixing system has the capability of supplying fluid at a rate greaterthan the combined output of all pumps. In addition, the concentrate-watermixing ratio will remain within 5 percent of its setting regardless of pressurefluctuations which might occur in the mixture supply line.The figure below shows a typical mixing system.



The mix water flows through a regulator which reduces the pressure andmaintains a constant flow rate. An independent air-operated pump injects thewater soluble oil at a constant rate, thus maintaining the proper mixing ratio.The system is insensitive to pressure and volume fluctuations in the mix watersupply as long as the rig water system is capable of supplying water faster.than the setting for the mixing system. The mix ratio can be adjusted by varyingthe mix water and/or water soluble oil flow rate. To protect the hydraulic fluidagainst freezing, the capability to mix glycol with the water soluble oil and wateris provided. The glycol would be added in a manner similar to that of the watersoluble oil. Glycol and water volumes are added when determining the amountof lubricant to add.

The main pumps for the power unit are typically electrically driven triplexpumps. The primary consideration when selecting the capacity of the pumps isusually the amount of time it would take the pumps to charge the systemaccumulators from their precharge pressure to the maximum system workingpressure. Charging times no longer than 15 minutes are desirable. There canbe other considerations which would override charging time and require morepump capacity. These considerations usually involve saving rig time, the cost ofwhich makes the cost of additional pump capacity negligible. When pumpcapacity requirements exceed 20 gpm, splitting the capacity between twopumps prevents complete dependence on one pump.

To provide additional or backup pump capacity in case electric power is notavailable, one to three air-operated pumps are usually installed. All pumps aremounted so that any one can be isolated for repairs without interfering with theoperation of the others.

The pumps are equipped with pressure switches to start and stop the pumps atselected pressures and suitable relief valves. To maintain maximumaccumulator fluid for a 3000 psi system, the pressure switch to stop the pumpsis set at 3000 psi. The relief valve vents at 3500 psi. The fluid from the pumpsis filtered by 40 micron filters. Two filters connected in parallel are used, witheach filter capable of being isolated to eliminate pump shutdown for filterreplacement.

Fluid travels from the pumps into accumulator banks. These accumulatorsserve two purposes; first, they store hydraulic energy which can be used whenpumping capability is lost. Second, they supply fluid at rates much higher thanthe pump capability and are used to achieve faster BOP actuation times.

Separator-type accumulator bottles are used in all of Shaffer control systems.They have a rubber bladder than separates the gas precharge from the storedliquid. The gas precharge is injected into the accumulator through theprecharge valve in the top. No fluid should be in the accumulator when it isprecharged. Cameron traditionally use float type accumulator bottles in theirsystems. The float replaces the bladder and it is the dropping float which shutsoff the bottle outlet to prevent the nitrogen from escaping from the bottle as thefinal fluid exits.



The surface control manifold contains all the controls and indicators necessaryto operate the valves and regulators on the subsea pods and monitor thegeneral status of the system. The manifold contains the pod selector valve,which directs the power fluid to the active pod and vents the inactive pod to thefluid reservoir located on the power skid. The manifold can be operatedremotely from any of several panels which will be discussed later. Thefunctions on the manifold can be broken into four categories, pilot valve control,regulator control, pressure readback display, and pod selection.

Each piece of equipment on the stack has a corresponding surface controlvalve on the manifold which pilots the pod control valve(s) that, in turn, controlthat piece of equipment. The control valves for the Shaffer system are 1/4-inchshear seal valves equipped with air operators to allow control of the valves fromthe remote panels.



The hydraulic signal from each valve goes to both junction boxes on themanifold unit, through both hose bundles, and actuates SPM valves on both theactive and inactive pods.

Only one subsea pod, the active pod, has power fluid or main hydraulic supply(MHS) fluid supplied to it at any given time. The pod selector valve on themanifold unit directs fluid to the active pod and vents the fluid from the inactivepod. The pod selector (a 1-inch shear seal valve) operates exactly like the pilotcontrol valves and is equipped with an air operator for remote operation.

The controlled pressure side of each regulator in the subsea control pods isconnected through a 3/16-inch hose to a gauge labeled pressure readback onthe manifold unit. A pressure transducer transmits the readback pressure tothe remote panels. A shuttle valve connects the hoses from the pods at themanifold unit and isolates the active and inactive pods.

Explosion-proof housings located on the manifold unit skid contain theequipment which interfaces the remote control panels with the manifold unit.This equipment includes the pressure transducers which transmit pressuresfrom the manifold to the control panels and pressure switches that providestatus information (open, close) for the remote panels. Also included are thesolenoid actuated valves which direct air to the air operators on the manifoldpilot control and pod selector valves and provide regulator increase/decreasecontrol.

2) Hydraulic Hose Bundle and Storage Reel

In hydraulic systems, the subsea power fluid supply, MHS, and all pilot signalsfor the control valves are transmitted through a hydraulic hose bundle whichextends from the surface manifold unit, through jumper hoses to the hose reels,and from the hose reels to the subsea pods. Also hydraulic fluid from theregulated side of the subsea regulators is transmitted through the hose bundleto pressure gauges labeled pressure read-backs on the control panels. MHSfluid is supplied only to the hose bundle of the active pod while pilot pressure issupplied to both the active and inactive pods.

The hose bundles used in most operations generally are composed of one 1-inch ID supply hose, which supplies power fluid to the pods, and 3/16-inch IDpilot hoses for activation of the individual control valves and readbacks. Thesupply and pilot hoses are typically bundled with the supply hose in the centersurrounded by pilot hoses. Polyurethane is the preferred outer coveringmaterial for the bundle because of its superior physical properties.

The hose reel stores and supplies the hose bundle as required during drillingoperations. A separate cable reel provides the means for easy running andretrieval of the pod. When the pod is run or retrieved, the junction box for thejumper hose is disconnected from the hose reel. However, to keep selectedfunctions live during the running or retrieval operations, a few control stationsare mounted on a manifold attached to the side of the reel. The live functions



include at least the riser and stack connectors plus the pod latch. Contractorsmay select to additionally operate one or two pipe rams, fail safe valves andtest valves. Below is a typical a typical diagram of reel piping through which thepower fluid flows to the controlled functions during the operation of the reel.

The hose bundle leaves the reel and runs over a roller sheave down to the pod.The bundle is clamped to the wireline attached to the top of the pod at 30 to 50foot intervals.

The pressure drop in the power hose can be substantial when a function isactuated, particularly for long hose lengths. One way to compensate for thispressure loss and assure faster actuation times is to place accumulatorssubsea on the BOP stack. Another means is to supply fluid to the control podsthrough 2 or 2-1/2-inch ID conduits integral with the marine riser. Theseconduits are similar to small diameter choke or kill lines.



1) Control PodsFlexibility in BOP stack configuration is provided by double female controls pods.The flexibility is achieved by having discharge ports in both the upper and lowerfemale portions and utilizing a combination of 3/4 and 1 SPM valves for preventerfunctions, depending on fluid requirements.

These control pods also are equipped with 1-1/2 regulators to provide large flowand still maintain accurate pressure settings. The packer seals at the mated portsbetween sections of the pod have been tested to 12,000 psi without leakage in thetransfer of high pressure fluid between sections. The subsea hose bundleterminates at the pod through a hose radius guard attached to the junction boxcover. This protects the hose from kinking and prolongs its life.

The pods are run and retrieved by unitized guide frames. Keyed connections providereliable mating.

The retrievable pod incorporates 1 SPM valves and 1-1/2 regulators with the SPMvalves mounted in individual stainless steel pockets for ease of maintenance. Packerseals make leakproof connections between pod sections, and special coatingsprotect the pod against corrosion.

Power fluid to operate the preventer is supplied to the pod through a one-inch hosein the hydraulic hose bundle or a rigid conduit integral with the marine riser. Powerfluid is also supplied from accumulators mounted on the BOP stack. Hydraulic powerfluid is normally supplied to the subsea control pod at full system working pressure;nominally 3,000 psi surface gauge. A regulator in the pod reduces the pressure tosuit the requirements of the BOP equipment, normally 1500 psi surface gauge.

The purpose of a regulator is two-fold. First, to reduce higher (system) pressure to alower (working) pressure. Second, to maintain the preset pressure should externalforces attempt to increase or decrease it. The regulator is controlled from the surfacethrough a pilot hose in the hydraulic hose bundle. The shear seal type regulatoremploys a sliding metal seat which seals on a fixed metal surface.



Centered

Fluid Vented

Cameron Slide Valve

Open

edSu

pply

ing

Flui

d



Open Supplying Fluid

ClosedFluid Vented

Shaffer SPM Valve



The regulated hydraulic fluid is supplied to selected SPM valves mounted onthe subsea pod. Pods may have two or three regulators depending upon drillingcontractor requirements. Pods with two regulators use one to supply regulatedfluid to the valves controlling the annular preventers, the other suppliesregulated control fluid to the remaining functions (ram preventers and valves).In some instances the connectors will have their own regulator.

The SPM valves are operated hydraulically from the drilling vessel throughsmall pilot hoses in the hydraulic hose bundle. When operated, they supplycontrol fluid to actuate the piston operators of preventers, valves andconnectors. At the same time they vent fluid from the other side of the pistonsto the sea.

SPM valves are two-position, three way valves and are available in 3 nominalsizes, 3/4 inch, 1 inch and 1-1/2 inch. One-inch valves and one and a half inchvalves are used to control the annular preventers. The 3/4-inch valves areused to control the other stack functions such as ram preventers, choke and killvalves, and connectors. The SPM valve is a poppet type in which a slidingpiston seals on Delrin seats. In the normally closed position, a spring attachedto the top of the piston shaft keeps the piston on the bottom seat, blockinghydraulic fluid from reaching the BOP. In this position, hydraulic fluid from theinactive function is vented to the sea. When pilot pressure is applied to thevalve, the piston moves up against the upper seat and blocks the vent ports,allowing control hydraulic fluid to reach and function the BOP.

Two SPM valves are required to operate a blowout preventer. The pilot fluidflows from the control valve at the surface, through a pilot hose to the SPMvalve and lifts the valve spindle off its bottom seat. Regulated fluid flowsthrough the SPM valve to the preventer cylinders CLOSE side. At the sametime, the three-position, four-way, surface control valve relieves pilot pressureon the preventers OPEN SPM valve. The spring forces the piston to its lowerseat and displaces pilot fluid to the surface. Hydraulic fluid from the OPEN sideof the preventer cylinder is vented subsea through this valve. Regulated powerfluid pressure acts on a small piston area on the spindle to aid the spring inholding the SPM valve closed.

The surface control valve when in the centered position relieves both SPMvalves of pilot pressure, thus allowing both valves to block or seal off theregulated power fluid and vent both sides of the preventer actuating cylinder tosea. When the control valve is in this position, it is said to be in the centered,block, or vent position. When SPM valves are operated in this manner, thetwo valves act as one three-position, four-way valve.



After passing through the SPM valve, the power fluid exits the pod and flows tothe appropriate function first through a hydraulic hose and then through ashuttle valve mounted adjacent to the function.

The shuttle valves, which isolate the inactive pod from the operated functions,are an integral part of the redundant two-pod design. Shuttle valves are usedto direct power fluid from the active pod to the function while at the same timeisolating the inactive pod from the control pod in use.A cut away drawing of the shuttle valve is located on page 40 where you cansee the internal operation.When the pods are switched, fluid from the active pod shifts the shuttle in thevalve to isolate the inactive pod from the function. Also, note that thecorresponding SPM valve in the inactive pod is piloted open concurrently withvalve in the active pod; however, no power fluid flows from inactive pods valvebecause the hydraulic fluid line has been vented on the surface.

Not all functions on the BOP stack are controlled through valves on the pod.Function that require less volume, e.g., ball joint pressure, are controlleddirectly from the surface through small hoses in the hydraulic hose bundle. Thefluid flows through a hole drilled directly through the pod. These functions arecalled straight through as opposed to functions requiring SPM valves.

Thus far, only the operation of a single function through the subsea pod hasbeen discussed. The pod must have additional capabilities or requirements tomeet todays drilling needs; some of them are: Capable of being run and retrieved with the riser package, Capable of being run and retrieved independently, To be fully redundant, To have all hydraulic seals on the retrievable portion of the pod, To have all functions go to the exhaust position if communications are cut

with the surface and, To allow any leaks occurring downstream of the pod to be isolated either at

the pod or upstream of the pod.

To meet the preceding criteria, the pods must be mounted on the upper stacksection (LMRP) which is retrieved with the riser.



2) BOP Remote Control PanelsThe Driller's Control Panel is the primary operating centre for the BOP ControlSystem: the electrically operated Mini Remote Control Panel and the manualoperated hydraulic Control Manifold are secondary centres. Operating voltage forThe Drillers Control Panel is typically 12 VDC or 120 VDC. The control panel isdesigned with a graphic overlay of the BOP stack and choke and kill lines. Thegraphic overlay helps the driller locate quickly the functions to be operated. Thedrillers control panel also enables remote operation of the diverter control functions.The controls for the diverter functions are also arranged in a graphic overlay for easeof identification. The entire control panel is protected from physical andenvironmental damage by two Lexan doors.

a) Function Pushbutton/Indicator LightsThe main section of the Driller's Control Panel contains the push button/indicatinglights for control of the BOP Stack and Lower Marine Riser Package (LMRP)functions.



These functions duplicate the functions on the Hydraulic Control Manifold. Atypical list of functions is listed below:

Stack & Riser Functions Function Positions Pod Selector Blue. Block. Yellow Accumulator Isolator Open. Close Blue Pod Latch Vent. Latch Yellow Pod Latch Vent. Latch Upper AnnularOpen Block Close Riser Connector Unlock. Block. Lock, Riser Connector Secondary Unlock Vent Shear Rams Open. Block. Close Upper Pipe Rams Open. Block. Close Middle Pipe Rams Open. Block. Close Lower Pipe Rams Open. Block. Close Outer Kill Open. Vent Inner Kill Open. Vent Upper Outer Choke Open. Vent Upper, Inner Choke Open. Vent Lower Outer Choke Open. Vent Lower Inner Choke Open. Vent Stack ConnectorUnlock. Block. Lock Stack Connector Secondary Unlock. Vent Upper Wedgelocks Unlock. Block. Lock Lower Wedgelocks Unlock. Block. Lock

b) Lamp Test PushbuttonTo the left of the stack overlay, is the Lamp Test pushbutton. When this button ispushed, all the panel lights should illuminate

c) Warning PanelTo the immediate right of the function pushbuttons is the warning panel. Thissmall panel typically contains five red alarm indicator lights for the following:

Glycol Level Soluble oil Level Accumulator Pressure Fluid Level Rig Air Pressure

If the pressures or levels of the above listed items drop to a predetermined lowlevel, the red indicating lights illuminates to warn the driller. The driller shouldcheck the low pressures and low liquid levels and restore them to acceptablelevels before proceeding with control system operations.



When any of the red warning lights come on, an audible horn also sounds at theDriller's Control Panel. To turn the horn off, the rig- hand presses the HornCancel button at the bottom of the warning panel.

d) System Pressure Meters

To the right of the Driller's Control Panel are two electrically operated Pressuremeters. The Accumulator Pressure meter indicates Line Pressure or the mainhydraulic supply from the main accumulator bottles to the stack functions. ThePILOT PRESSURE meter indicates the pressure in the pilot system. The RIGAIR PRESSURE meter indicates the rig air pressure to the Hydraulic Power Unit.The correct meter readings are as follows:

Pilot Pressure 3000 Accumulator Pressure 3000 Rig Air Pressure 100- 125 psi

e) Flow Meter

A flow meter is located on the Driller's Control Panel immediately below the twopressure meters. The flow meter on the panel indicates the amount of fluid thathas been used at the completion of a function operation. The electric flow meteron the Driller's Control Panel is linked to the hydraulic flow meter on theHydraulic Control Manifold. The flow meter registers the volume in tenths of agallon. Careful observation of the flow meter can signal the driller that a leak ispresent in the control system. After a function has been operated, the flow meterat the Driller's Control Panel can be reset to zero by pressing the FlowmeterReset pushbutton to the left of the flow meter.

f) Pressure Regulation Stations

On the left side of the Driller's Control Panel are five additional electricallyoperated pressure meters. These meters are:

Annular Regulator Pilot Pressure Annular Regulator Readback Pressure Manifold Regulator Pilot Pressure Manifold Regulator Readback Pressure Pilot Pressure

The readings on these meters correspond to the readings on the pressuregauges on the Hydraulic Control Manifold.

To the right of the meters are two increase, decrease pushbutton stations. Onestation is for the annular pressure regulator, the second is for the manifoldpressure regulator. Note that the three-way Unit/Remote Panel Selector switchon the Hydraulic Control Manifold must be in the Remote Panel position before



the regulator pressures can be controlled from the Driller's Control Panel. Whenthe driller operates either the annular pressure regulator or the manifold pressureregulator, the pressure is indicated on the Annular Regulator Pilot Pressure andManifold Regulator Pilot Pressure meters respectively. When the regulatedpressure pilot signal is retrieved subsea, the subsea HKR regulating valves sendsignals back to the Drillers Control Panel. These return signals are indicated onthe two readback pressure meters. When all system equipment is operatingcorrectly, the Pilot Pressure and Readback Pressure meters for the two regulatedfunctions read the same.

3) Diverter Control Section

a) Function Pushbutton Indicator LightsThe right side of the typical Drillers control panel contains the controls for thediverter control system. These controls enable remote operation of the diverterequipment from the Drillers control panel. The diverter control section of theDrillers control panel contains the pushbutton/ indicator lights and regulators forcontrol of the diverter functions. The panel is designed with a graphic overlay ofthe diverter functions, which helps the driller locate quickly the functions, whichare to be operated. The seven functions reflect the functions of the divertersubstructure panel. The functions and positions are listed below :

Positions FunctionOpen, Close Diverter ElementUnlock. Lock Insert Packer Lockdown DogsUnlock. Lock Diverter Lockdown DogsUnlock. Lock Diverter Support Lockdown DogsVent. Pressure Flowline SealsOpen. Close Shale Shaker ValvePort / Starboard Open Overboard Valves

Unlike the panel functions or the BOP Control System, the panel functions for theDiverter Control System do not contain Block positions. Diverter functions can beput into the Block position only at the Diverter Substructure Panel.

b) Pressure Regulation StationsThree sets or pressure regulation pushbuttons are located in the center of thediverter control section. The three pressure regulators are for the DiverterElement Regulator. Diverter Manifold Regulator. and Slip Joint Regulator. Eachregulator is provided with an Increase and Decrease pushbutton.

Note that the three way remote panel selector switches at the divertersubstructure panel must be in the remote panel position before the regulatorcontrol pressures can be controlled from the drillers panel.



Pressure Meter Operating Pressure (psi)Diverter Element Pressure 750Slip Joint Pressure 300Diverter Manifold Pressure Drillers choice

(usually 1000 to 1250 psi)

A fourth pressure meter for the Diverter Accumulator Pressure - Is located on thediverter section on the Driller's Control Panel. This meter displays theaccumulator pressure or, the Diverter Substructure Panel and should, read 3000psi.



Hydrostatic Effects onSubsea Accumulator Bottle Precharge

3000 psi Working Pressure System

Water Depth Precharge, psi(1,000 psi + Water depth x .445psi/ft)

Available Fluid from10 Gallon Subsea

Bottle 1

0 ft. 1,000 psi. 5.0 gal.

500 ft. 1,223 psi. 4.8 gal.

1,000 ft. 1,446 psi. 4.6 gal.

1.500 ft. 1,669 psi. 4.4 gal.

2,000 ft. 1,890 psi. 4.2 gal. 1 Calculated on a 3,000 psi WP system using 1,200 psi as the minimum usable fluid pressure. The % of

usable fluid delivered from the bottle is equal to:(precharge + hydrostatic head) (-)minus (precharge + hydrostatic head)(Min. pressure + hydrostatic head) (System WP + hydrostatic head)



API and MMS System Sizing and Response Guidelines

Reference Response Time Requirements Accumulator SizingCriteria

API RP-53, 3rd Ed.Response - Sec. 13.3.5Volume - Sec. 13.3.2

Rams close in less than 45 sec. Valves not to exceed rams Annulars close in less than 60 sec. LMRP Connector unlatch in less

than 45 sec.

Close & Open all rams plus oneannular with remainingpressure to be 200 psi aboveprecharge pressure

API Spec 16DResponse - Sec. 2.2.2.1Volume - Sec. 2.2.2.5

Rams close in less than 45 sec. Valves not to exceed rams Annulars close in less than 60 sec. LMRP Connector unlatch in less

than 45 sec.

Open & close all rams plus oneannular plus 50% reserve withremaining pressure to be aboveprecharge pressure

then

Open & close all rams plus oneannular with remainingpressure above calculatedminimum ram or valveoperating pressure

MMS CFR 250Chapter II Subpart DSec. 250.406-d-1

1.5x the volume to close allpreventers with remainingpressure to be 200 psi aboveprecharge pressure



BOP Response Times

The closing time of a subsea BOP control system consist of two parts: signal time andfill-up time.

The signal time is the elapsed time from when a function on a panel is operated until allvalves in the sub-sea pod have operated. The fill-up time is the elapsed time from whenthe valves in the pod operate until the stack function if fully operated (open or close)

1) Signal TimeIn an all hydraulic system there are five factors which affect signal time.

a) Hose length - this is a customer requirement and cannot be changed. For eachtype hose the greater the length the slower the reaction time.

b) Hose Volumetric expansion - a stiffer hose, i.e., a lower volumetric expansion willproduce a faster signal transmission.

c) Hose diameter - for a constant length and stiffness, increasing the diameter ofthe hose within limits will decrease the signal response time.

d) Temperature - tests or calculations at room temperature are inadequate.Corrections must be made to account for the colder water (approximately 350F)since most of the hose will be underwater. Colder temperatures will cause alonger response time. Response time calculations typically are at 350F.

e) Amount of ethylene glycol - for adequate antifreeze protection, a 40% solution ofethylene glycol should be used in the pilot lines while operating in sub zerotemperatures. Increasing the concentration of ethylene glycol will significantlyslow the response time of a given hose.

2) Fill Up TimeFill up time of a preventer is affected by the supply of fluid and the hydraulic circuitryon the stack.

a) Fluid supply to preventers is accomplished in two ways. Fluid is delivered fromthe surface via hose or rigid conduit. Fluid can also be supplied from stackmounted accumulators. If lines from the surface to the annular are not able todeliver fluid at a minimum of 180 gpm for an 18 3/4 10,000 psi annular thenstack accumulators are necessary. The accumulators should contain enoughusable fluid to close one annular.



b) Hydraulic circuitry between the pod and preventer restrict the flow of fluid to thatpreventer. Connections to an annular may include two one inch SPM valvessupplied by a 1 inch regulator and sufficient usable fluid in stack mountedaccumulators to close the annular. In tests on fill up time conducted on Shafferpods in the ship yard, to close an 18-3/4 inch 5,000 psi Spherical required 18 to21 seconds. The 18 3/4 inch 10,000 psi Spherical with the same circuit will closein 28-30 seconds. Connections to the annular included four one inch SPMvalves supplied by a 1 1/2 inch regulator and sufficient usable fluid in stackmounted accumulators to close the annular.



HYDRAULIC SYSTEM FLOW

1) Main Hydraulic SupplyHydraulic fluid, made up by automatically mixing potable water and water soluble oilconcentrate, is stored in a reservoir. It is picked up by electric pumps and/or airpumps and flows through two 40 micron filters in parallel. The fluid then enters abank of accumulators where it is stored at a maximum pressure of 3,000 psi (with a1,000 psi nitrogen precharge in accumulators). The hydraulic fluid also continuesthrough a flow meter (FM). An accumulator pressure gauge is located on the front ofthe hydraulic control manifold and a pressure transducer (PT) transmits pressurereadings to the remote panels. A low accumulator alarm switch activates wheneverthe accumulator pressure falls below 1,500 psi.

Hydraulic fluid flows from the accumulator bottles through a 1 check valve on itsway to a 1 manipulator type 4-way valve which selects the pod which receives theMain Hydraulic Supply (MHS) The pod which receives MHS is called the active pod.The pod selector valve is on the front of the accumulator unit and operates eithermanually or remotely for a remote panel. When MHS flows from the valve to eitherof the pods, the pressure activates either one of the pressure switches in the outputlines to operate the appropriate pod indicator light on the remote panels to indicatethe active pod.

Main hydraulic supply leaves the pod selector valve and flows to the BOP controlpod located subsea. This line is a 1 hydraulic hose located in the hose bundle. TheMHS line enters the pod through the large connection in the center of the kidneyplate. The flow then continues to the two subsea regulators (1 l/2 HKRs).

Some systems send the fluid subsea down a rigid conduit line. This is permanentlyattached to the riser in a manner similar to a choke and kill line.



2) Regulator Pilot Circuits

We now need pilot lines to control the two subsea regulators (HKRs). Pressure issupplied from the main accumulator bank through a 1 check valve to the manifoldpilot pressure regulator and the annular pilot pressure regulator. These tworegulators (1/2 AKRs) in the hydraulic control manifold apply pilot pressure throughthe pilot lines (MR and AR) to the subsea manifold and annular HKRs, respectively.Regulator pilot pressure is also fed to panel mounted gauges & pressuretransducers.

The subsea HKRs supply output pressure at a 1 to 1 ratio. A 1,500 psi pilotpressure produces 1,500 psi output pressure from the subsea HKR for the blowoutpreventers.

The output of the manifold subsea HKR goes to all of the ram preventer, valve, andconnector functions while the output of the annular subsea HKR supplies power onlyto the annular preventers. A pilot line leaves each of the subsea HKRs and returnsback to the surface through the hose bundle. These two, 3/16 lines supply manifoldand annular readback pressures to gauges and pressure transducers located on thehydraulic control manifold. A shuttle valve is located on the input to each gaugebetween readback lines from both the blue and yellow pods (This Pod and ThatPod). Since there is no MHS to the inactive pod, only the active pod suppliesreadback pressure through the shuttle valve to the gauge and pressure transducer.



3) Operation of a 3 Position Function

The pilot pressure required to control a function begins at the main accumulatorswhere 3,000 psi hydraulic fluid supplies two, ten gallon pilot pressure accumulatorbottles (with 1,500 psi precharge) through a 1/2 check valve. The pressure in thepilot pressure accumulators is monitored by a gauge and pressure transducer.These pilot pressure accumulators supply pressure to the manipulator valves onthe front of the hydraulic control manifold. Here we see a valve to control a HydrilBOP. Pilot lines (number 29 and 36) leave the manipulator valve, connect topressure switches, then leave the manifold and go to both pods (both This Pod andThat Pod). Once in the pod, both lines connect to SPM valves. Both SPM valvesattempt to supply hydraulic pressure to either open or close the annular preventer.Remember, only the active pod receives MHS and actually operates the preventer.

When the handle of the functions valve is operated, pilot pressure leaves the manipulator valve through one pilot line and activates the associated pressureswitch to turn on an indicator light on the remote panel. The pilot pressure thenenters both hose bundles and continues subsea to the kidney plates. The pilot linesthen lead to the proper SPM valve in each control pod. Pressure forces the SPM(Sub Plate Mounted) valve into the open position. This then allows hydraulic fluid toflow from the subsea annular HKR and through the open SPM valve to operate theannular preventer.

The opposite pilot line is simultaneously vented by the manipulator valve, releasingpressure in that pilot line. When pilot pressure is released from the opposite SPMvalve, the SPM returns to the closed position by spring action and vents operatingpressure from the BOP into the sea.

Note that both pods receive pilot pressure but only one pod will actually be supplyingfluid to operate the preventer. This is the pod which is receiving Main HydraulicSupply (MHS) pressure from the pod selector valve.

In the center, or block position, the manipulator valve vents both pilot lines to theAnnular BOP. This allows both SPMs to close and vent all control pressure off thepreventer. The Block position indicates that the Control System blocks pressurefrom going to the function and vents all control pressure off that function.



4) Operation of a 2 Position Function

A two position function differs from a three position function due to the presence ofonly 1 pilot line from the pilot valve. The two position function reefers to the ability ofthe circuit to only supply pressure and vent hydraulic pressure. These functions areused for such items as subsea failsafe valves which must be pumped into the openposition or vented to allow them to close under their own spring power. Otherapplications are Connector Secondary Unlock, where pressure is applied or vented.

Power for either pilot pressures originate in the pilot accumulator bottles. Only onepilot line leaves the manipulator valve of a 2 position function. Leaving the valve,the pilot line leads to a pressure switch and to both pods by way of the RBQs, hosebundles, and kidney plates. The single pilot line then leads to the proper SPM in thesubsea control pod.

When it is desired to open a subsea failsafe valve, it must be pumped into the openposition against spring force. To initiate this, the manipulator valve is put into theopen position . This supplies pressure to the pressure switch in the pilot line whichturns on the indicator light on the control panel. The pilot pressure also enters bothpods through the pilot lines and activates the proper SPM valve. The SPM valve isforced into the open position which allows hydraulic pressure to flow from thesubsea manifold HKR in the active pod, through the open SPM, and into the openingchamber of the subsea failsafe (fail-safe) valve.

When it is desired to close the failsafe valve, the manipulator valve is placed inthe center, or close position, which vents off all pilot pressure to the subsea SPMvalves and the pressure switch. The pressure switch turns on the proper indicatorlight on the remote panel. With pilot pressure removed from the SPM valves, theyreturn by spring force to the closed position and also vents pressure from theopening chamber of the subsea failsafe valve. With no hydraulic pressure to hold itin the open position, the failsafe valve closes due to spring force.



5) Operation of a Straight Through Function

Functions which use small volumes of fluid use 3000 psi pilot pressure directly at thefunction and avoid the requirement of an SPM valve. These are often items such asthe pod latch (shown here as the manipulator valve on the far right-hand side), stackmounted SPM valves for stack mounted accumulators, and ball joint pressure.

With these functions, pilot pressures are sent down to the pod through the hosebundle from manipulator valves located on the hydraulic control manifold. Pilotpressures flow through the pod directly to the pod latch piston or through the pod tostack mounted SPM valves

Ball joint pressure originates at the ball joint pressure regulator located on thehydraulic control manifold. The pressure is carried down a pilot line through theupper female and to the ball joint.



Typical Hydraulic Power Unit Schematic



Typical Manifold Schematic



Typical Pod Schematic



Typical Stack Schematic



Shuttle valves for redundancy

1. Shuttle valve - the point where the redundant systems, blue and yellow, cometogether.

2. Shuttle makes a decision "Who is going to operate this function, blue oryellow pod"

3. Shuttle is passive. It is shifted by the active pod when pods are shifted.4. Mounts directly onto the preventer since redundancy stops at this point2

5. Stops flow out through shuttle into the inactive hose and pod if there shouldbe a leaking hose on the inactive pod.

2 Systems which are hard piped from the shuttle valve to the equipment port may deviate from thisgeneral rule.



Hydraulic Symbols

1) Hydraulic and Air Lines

Preferred Acceptable ANSI

Hydraulic Air

2) Check Valves

Simple Pilot OperatedCheck Valve (POCV)

3) Shuttle Valve

4) Relief Valves, Adjustable



5) Regulators

Manually Adjusted Hydraulically Piloted

6) Miscellaneous Items

Flow Meter Gauge Pressure Switch Pressure Transducer

7) Pumps

Air Driven Electrically Driven

8) Accumulator Bottles



9) Valves, 2-way

Needle or Ball Valve

10) Spool and Shear Seal Valves, 3 and 4-way

Manual2-way

Manual 4-way3-positionSelector

Manual 4-way3-position

Manipulator

Return toReservoir

Plugged Unconnectable

Air Pilot andManual Operation

Hydraulic PilotOperation

with Spring Return

SolenoidOperation

with Spring Return



Survey of Fittings Found on the BOP Stack

1) Threaded Fittings

a) Tapered Pipe ThreadsThe tapered pipe thread, either U.S. or British, has always had a sealingproblem. The U.S. thread is NPT (National Pipe Taper) and the British thread isBSP.

The wedging action of the pipe taper will always be a problem. Any poorlytrained mechanic can take a large wrench to a pipe fitting and by putting toomuch torque on the wrench he can split the casting of an expensive componentbecause of the wedging action of the taper. At sizes above 1" the NPT fitting isnot rated for pressures above 3,000 psi.

b) Straight Thread FittingsTo solve the problems of a tapered thread a straight thread has been developedwhich seals with an O-ring. The thread machined into the housing is an SAE finethread, but at the top, a chamfer is machined which will accommodate the O-ring.

When the fitting is screwed into a port it can be tightened until the fitting makes ametal-to-metal seat on the housing and the O-ring provides the fluid seal. Sincethere is no taper on the threads, there is no wedging action to split the housing.



2) Flare Fittings

a) 45o SAE Flare FittingsThe concept of flaring tube to provide a seal and holding power to the connectionis very old. Its origin goes back to the early days of the automobile. Differenttypes of flared connections including 45o single and double flares, inverted flare,30o flare, etc., were developed for coolant, fuel, brake and lube systems of theautomobile.

The SAE (Society of Automotive Engineers), formed in 1910, made itselfresponsible for the manufacturing standards of all items used in automobilemanufacture, and tubing was one item to be so controlled. A set of dashnumbers was introduced so that the manufacture's part number followed by adash and a number would identify it as being made to SAE standards. Dashnumbers such as -5 for 5/16" O.D., were assigned with similar dash numbers forother sizes.

A hand flaring tool was developed so mechanics could make an outward flare onthe end of a piece of copper tubing, and the inside flare surface always finishedoff with an exact 45o angle. This became the standard angle for all SAE flarefittings.

The thread, identifying dash numbers, and fitting to be used with each size tubewas regulated by SAE. This was the beginning of all the dash sizes we nowhave in use in fluid power connectors.

The American made hose ends and adapter fittings did not match with thosemade in other countries, especially in Europe and Asia. The confusion wasespecially felt in the oil well drilling business as the drilling rigs were moved fromone location to another.

b) 37o JIC Flare FittingsThe 37o flared fitting is the most widely used fitting throughout the world.Because the fitting can be used to connect to inch tubing, metric tubing and alsoa hose assembly, this versatility offers the user a greater internationalacceptance as compared to other fitting styles.



With American support, arrangements were made with manufacturers in manyother countries for an all-world seminar to arrange common standards. Thisseminar was called the Joint Industry Conference and the standards which cameout of it were called JIC standards. The first thing to be done was to make aneasily noticed difference between an SAE and a JIC fitting. The face chamferangle on the female hose ends was changed to 37o, enough difference to benoticed by the eye. Also, many thread sizes were made to different diameters soJIC fittings would not mate with SAE fittings. In some cases the number ofthreads per inch was made different. Each mechanic could tell that a JIC fittingcould not be used with an SAE adapter.

However, a variation of the dash numbering system was agreed upon for thehose manufacturing trade, so that the I.D. sizes were in sixteenths of an inch.Thus, 1/2" I.D. hose became 8/16 " or -8 size. The JIC hose ends for the "hose have female JIC swivel end fittings are identified with the same dashnumber, -8, for example.

3) Bite Type FittingsThe bite type fitting is a flareless fitting that consists of a body, a one-piece ferrule,and a nut. On assembly, the ferrule "bites" into the outer surface of the tube withsufficient strength to hold the tube against pressure, without significant distortion ofthe inside tube diameter. The basic bite type fitting was first developed in Europe inthe early 1930s.

The bite type fittings provide a fairly secure and easily made-up method ofemploying tubing on the control system. The bite type fittings are generally notconsidered as "bullet-proof" as the 37o JIC fitting system.

The ferrule also forms a pressure seal against the fitting body. Bite type fittingsallow the fitting assembler to visually inspect the bite quality, thus significantlyminimizing the risk of improper assembly and related service problems



4) Flange Fittings

a) SAE FlangeThe SAE flange hose end fitting has come into wide usage in the last severalyears since system operating pressures have risen above 3,000 psi (the limit forlarge diameter NPT threaded fittings). It is primarily intended for high pressureconnection of a hose to a component port pad. It is only for hose and is notnormally used on rigid plumbing. The flange end fitting is crimped on to the endof a hose or the end of the hose is threaded into a flange block. These fittingscome either as a straight-through connection or with various angles from 22 o

to 90 o. The flange is clamped to a machined port pad on the component, usuallya valve, pump, valve manifold, or BOP, by two half flanges using hex head capscrews. An O-ring fits into a circular groove in the hose flange and makes a sealagainst the port pad on the component.

These flange fittings are made in several pressure ratings, for pressures from2500 to 6000 psi. They are available in sizes as small as 1/2" and up to 3inches. Although they were originally built for mobile hydraulic systems, they arebeing used on industrial systems as well. Size identification is with dashnumbers similar to those used on other fittings, expressed in sixteenths of aninch.

Several variations of the basic design have been developed. The Code 62 is themost common type used in BOP control systems.

b) SAE Flange with Integral Seal SubA modification of the SAE flange is to replace the face mounted O-ring seal witha radial seal in both halves of the connection. A seal sub is an additional itemwhich is added to the assembly to form the radial seal in both halves of theconnection.



Troubleshooting: Pressure Losses

While the B.O.P. is down, pressure losses do occur. Isolating them as best as possibleand repairing the components where possible can keep downtime as a result of pullingthe BOP or Pods at a minimum. The areas that losses are sorted into 5 categories.

1) The Koomey Unit the Hydraulic Power Unit (HPU)Components, which are the most common sources of pressure losses at surface,are:

Pod selector valve. Relief valve. Check valves on the air and electric pumps discharges. Hydro-air pressure switch. Increase/decrease solenoids. Manual regulator. Tubing and piped connections. Four way valves.

Most components above can be easily repaired (at an opportune time such as bittrips, etc.) by securing pressure to the components and securing the air and electricpumps.

Four way valves for instance one or another may not be possible to change out ascircumstances dictate and would have to be prolonged until the B0P/LMRP is pulled.Operations will always dictate how and when repairs can be conducted safely.

2) The Pilot SystemThe pilot pressure system begins at the two pilot pressure accumulators at theKoomey Unit and ends at each pod block. A pressure drop on the HPU pilotpressure gauge while the unit is idle will indicate a loss of pressure in the system.Components in the system are:

Tubing/pipework from the accumulators to the 4 way valves. The 4 way valves, and regulators. RBQ junction plates for each jumper hose. The RBQ junction boxes at each pod reel. The hose reel hot line system. Any splices or damaged areas in each hose. The termination of the pilot hoses to the kidney plate. The stainless steel tubing and connections from the pod top plate assembly to

the pod valve block. The pilot signal passage way in the pod valve block and the SPM.



a) Any leaks found in the tubing/piping can be visually found and stopped bysecuring the pressure to that function.

b) On the 4 way valves most leaks can be detected by listening to the valve andlistening for a washed valve body. Also the regulators and the 4 way valves canbe checked for pressure loss by removing the vent return lines and watching fora leak.

c) A visual check on the RBQ's both at the Koomey Unit and the hose reel and thepilot line connections should reveal any leaks.

A way of decreasing the chances of having a leak at a junction box, is by firstvisually inspecting the male/female check valves for debris, broken O-ring, andsecondly by placing all the functions, where possible, into the block position atthe 4 way valves when the junction box is removed or installed. If there is nopressure on the check valves when mating them together there is less of achance of washing out or cutting the O-rings before the junction plates are fullymated.

d) The pod reel hot line system gets its power from the 1" -3000 psi supply line andit is still possible to lose pressure in the pilot system. Since the hot line system 4way valves and regulators tie into the main pilot line/hose inside the reel, anypressure applied to the pilot lines once the hose reel junction boxes are matedcan back flow through the components and be lost through the vents. Bysecuring the supply valves and keeping the check valves in good order, thechance of this happening can be greatly reduced.

e) Although pressure losses can occur from damaged areas in the pod hose, thiswill most likely be the last place that you'll look. Leaks here will be hard to detect.That's why it is essential when the pod or BOP is on deck and being tested anypressure losses should be scrutinised so that you can be absolutely sure that youcan eliminate this area as a possible source pilot line pressure losses.

f) As above, the termination of the pilot hoses to the pod top plate assembly andthe stainless steel tubing and the connections to the valve body are not areas ofhigh probability where you are going to have leaks. However if these areas arecorroded particularly at the kidney plate, they can become high suspect areas.

Also consideration should be given to this area if you know that an object (T.V.frame, guideline tools may have hit or jarred the pod guide arms).

g) The SPM, besides the check valves at the pad hose reel, is going to be the mostlikely place for a leak in the pilot line system.



SUMMARY

If you have a leak in the pilot line system and you can rule out the loss ofpressure is occurring top side then the way to find this leak is by systematicallyplacing each four way valve into the block position and observing the leak untilyou find the pilot signal that is losing the pressure. Once the leak is found anddepending upon it's severity and the rigs situation any action or no action may betaken.

3) The Accumulator/Pod Manifolds System and BOP Functions:The accumulator/pod manifolds system provides the way for fluid to get to the SPMat the right pressure to be sent on it's way by the SPM to the designated function onthe BOP. The components that must handle this fluid are:

Accumulator bottles at the Koomey unit. Pod selector valve. Pod hose, reel swivel connection, pod hose. The 3000 psi pipe work from the pod top plate to the regulators and the

discharge piping to the valve block. BOP accumulator isolator valves The internal pod valve block manifolds. Hoses from the pod receptacles to the shuttle valves. Hoses from the shuttle valve to the functions on the B.O.P.

Most probable leak points are:

a) The accumulator bottles; unless there is a visual leak here in the pipe work to thepod selector valve you won't have any problem.

b) Any leak associated with this entire system will show up on the flowmeter and onthe accumulator pressure gauge.

c) The Pod selector: the selector valve (which is of the manipulator type) can beeasily checked for leaks. Listen to the valve for leak noise with a mechanicsstethoscope. By breaking the pipe work on the return side of the 1 pod valveany leak can be checked visually.

d) The Pod hose reel swivel connection, and pod hose; unless you can visually seea leak in the top side of this system the only way to isolate the 1 hose down tothe pod is to do the following:

e) Bleed down both the pilot signals to the pad manifold and annular regulators andput the riser connection 4 way valve into the block position, this will isolate the



3000 psi 1 hose, the 3000 psi pipe work in the pod and the 3000 psi systemdownstream of the subsea accumulator SPM. A loss of pressure will be indicatedon the accumulator pressure gauge. To continue and to find the leak, send a pilotsignal to the Subsea accumulator SPM establishing communication to thesubsea bottles. Observe for leaks. If no loss of pressure is found, continue on byplacing each 4 way valve into block (thus closing all SPMs).

f) By putting a pilot signal to each regulator you will find if you have any leakingSPMs while they are closed. Next, by placing each 4 way valve into the drillingmode (rams open, annular open, failsafes closed) this will detect if the leak istaking place from the open SPM to the designated function. If a leak is foundhere, to determine if it's from the open SPM to the shuttle valve or from theshuttle valve to and including the function just switch pods. Then place all 4 wayvalves into block and individually open the suspected leaking function. If the leakis not found here then this will tell you the leak is not from the shuttle to thefunction. The problem must be the SPM or the hose going to the shuttle valve. Ifthe leak is still found on the other pod then the leak is from the shuttle valve tothe function.

SUMMARYOnce it is determined where the pressure loss is occurring, a number of actionscan take place. They are:

1. Put pressure on the leaking SPM/function line then place 4 way valve intoblock position and leave it like that.

2. Switch pods.3. Pull pod.4. If leak is below (downstream) SPM/pod, the BOP stack or LMRP will have to

be pulled.

In conclusion, if the leak is to the main 3000-psi hose or pipe work or if aregulator is leaking the pod will most likely have to be pulled and repaired. If theSPM is working and you are losing pressure through it, and it holds pressurewhen it is closed (the SPM) you can most likely leave it in the block position untilthe BOP is pulled. And finally if the leak is from the shuttle valve to the functiondepending upon the situation the B.O.P. will have to be pulled to repair the leak.

4) Hose Reel ManifoldThe hose reel manifold is designed to give control to the pods so that a few primaryfunctions can be operated while the BOP is being run or pulled. The system shouldbe used during these times and not during normal operations.



The hose reel manifold receives its primary fluid pressure from the 1-3000 psi feedinto the reel via the swivel connection. A 3/16 I.D. jumper hose tee off from the 1"line feeds the main shut off valve for the hot line system (manifold supply shut off).

The manifold supply shut off feeds a common manifold from which the following 4way valves are fed fluid pressure:

Riser Connector - primary latch and unlatch SPM's. Riser Connector - secondary unlatch SPM. Wellhead Connector primary latch and unlatch SPM's. A Shear or Pipe Ram open and closed SPM's (pending hook up). A regulator for ball joint pressure. (This is no longer required but some older rig

systems may still have the regulator not hooked up). A regulator for the manifold pressure command pilot signal to the live pod.

Selecting one of the above pod hose 4 way valves; Riser Connector SecondaryWellhead Connector, Shear or Rams, and placing it in the desired mode of operationsends a pilot signal to the pod to lift that particular SPM. With the manifold regulatoradjusted to 1500 psi and with the manifold regulator shut off valve open a pilot signalis sent to the manifold regulator at the pad. With this signal the regulator will thenregulate the 3000-psi feed to the desired pressure (1500-psi). Now with the SPMlifted off of its seat, manifold pressure can now flow to the desired function andoperate the function. With the 4 way valve kept in the desired mode (say riserconnect lock) and with the pod reel regulator adjusted to 1500 psi, the regulator willreduce the 3000 psi feed to 1500 psi, and keep 1500 psi on the riser connector lockwhile the BOP is being run or pulled. Obviously this is of primary concern whilstrunning or retrieving a BOP stack - maintaining hydraulic closing pressure on theL.M.R.P. connector.

An important consideration to keep in mind while working and the way valve is thatthey are of the selector type . If a manipulator type body is installed once the reelhot line system is shut down and the junction box is mated together any pilot signalusing the above 4 way valves can be bled off because a manipulator valve bleeds ofpressure from its functions while in block, where as the selector valve will holdpressure in the block position. Therefore Pod hose valves should always be selectortype which will not bleed off pressure when thrown into a block position.

a) The procedure for activating the reel hot line system for running or pulling theBOP is as follows: Place the pod selector to either blue or yellow pod (use the same pod that

was previously used). Go to the hose reel and check to see if all 4 way valves are in block, if not

put them in the block position.



Open the manifold supply shut off valve. Open the manifold regulator shut off valve. Adjust both regulators to the desired operating pressures (manifold 1500

psi). If BOP is to be run, place riser connector to lock position wellhead connector

to open (unlatch) position. REMOVE THE HANDLE TO THE RISERCONNECTOR VALVE WHILE RUNNING OR PULLING THE B.O.P. AS ASAFETY PRECAUTION.

If BOP is to be retrieved put the riser connector to lock, and wellheadconnector to the latch position. Then put manifold pressure at pod reel tominimum 1500 psi.

Go to Koomey Unit, place all four way valves into the block position, bleed offregulators, place regulator selectors to block position.

Remove junction boxes from hose reels and activate hose reel functions. You are ready to go about with your BOP stack operation.

b) To deactivate the hot line system if the BOP is down: Mate on junction box, make sure air to motor and lock pin on reel is engaged. Go to unit, place all 4 way valves into the drilling mode (rams open, annular

open, failsafes closed and (Connectors locked). Select mode of operation for the regulators (electric or manual). Set

regulators to drilling pressures. Go to the reel and secure the manifold regulator shut off valves. Bleed down regulators. Place 4 way valves into the block position. Secure manifold supply shut off valve.

c) To secure the reel hot line system if BOP is on deck: Secure ball joint and manifold regulator shut off valves. Bleed down regulators. Place 4 way valves into block position. Secure manifold supply shut off valve.

d) A few comments about the Pod Reel hot line system: To avoid any confusion at the pods, always use the reel hot line system on

the pod that is on line. The hot line system is not to be used when the reels junction boxes are

mated. The 4 way valves are of the selector type.



Troubleshooting: SPM Failure

1) 42 Line PodScenario: B.O.P. on beams ready to be run or at the wellhead and a function fails to

operate. What should be done?

a) If no fluid flow is indicated by the flowmeter check the following: The Pod selector valve is selected to proper pod. The Regulator pressures: manifold and annular regulator selectors are in

proper mode and both regulators have the right amount of pressure on them -Check read back gauges to verify.

Pod reel junction box is on and secured. Pod reel hot line system is secured. To do this check:

a) 4 Way valves are in block position.b) The Pod reel shut off valves (manifold supply, manifold regulator and the

prehistoric ball joint regulator if still in use) are closed.c) The Regulators are bled off.

b) Switch pods, try same function again (same panel): If function works this tells you that your problem is between the RBQs (for

that pad that did not work) at Koomey Unit to the shuttle value going to thatfunction.

If function still does not work check out:a) Air pressure at Koomey Unit.b) Electricity to unit (proper current, voltage).c) Obstructions that may stop the 4 way valves from working.

c) Try function again from another source and if the function works then check out: Panel which would not operate: The easy way to check out the solenoid is to

disconnect the air fitting to air piston. `Try functioning again and you shouldget a shot of air. If you don't check out the electrics for that function andsolenoids. (Electrical box right hand side of main control panel).

If function still doesn't work review steps 1 a If the function did work on the other pod, switch back to the pod which is

malfunctioning.

d) Try functioning it again, if it still doesn't work: Go to pod reel, find proper pilot line and disconnect it on the inside of the reel

so that you can see if the signal is getting through the junction box checkvalves. Be sure pod hose reels are locked out and can not be rotated.

If you are getting a good pilot signal through, then the signal you are gettingshould be a good one at the pod. Obviously a leaking pilot line in the hosebundle can prevent the signal lifting the SPM.



If you don't get a signal here, reconnect pilot line and disconnect it on theoutside of the pod reel before the check valves, if you get a signal here theneither the male or female check valve is damaged -change out the checkvalve.

If you don't get a signal, go to Koomey unit and inspect the check valves onthe RBQ and also check to see if the correct pilot line is hooked up betweenthe unit and pod reel.

e) If you are getting a good pilot signal to the pod: Try another function that will use the same regulator on the pod to determine

if the regulator is shot. If the other function works you can be fairly sure that:

a) The SPM is not working.b) The shuttle valve is jammed and not allowing the fluid flow to the function.c) Or the component functioned is inoperable.

f) If at anytime that you operate the function and the fluid flow doesn't stop and thefunction works on the other pod then you have a broken hose or connection onthe pod side to that particular function.

Once you have the problem isolated to an SPM, then the only operation to pullthe pod (see section on PULLING A POD). After pulling the pod, repairing the SPM, function testing it on surface, rerun

the pod. Use a T.V. camera, don't stab it blind. Function test pod. If the function still doesnt work from any source, the shuttle valve must be

jammed. Depending on the particular function, wellhead connector, shear orpipe rams, failsafes, or lower annular then both halves of the BOP will have tobe pulled. If the riser connector, upper annular, or choke and kill connectorSPM1S fail then your only need to pull the L.M.R.P. section to surface.

g) Basically a function needs only 4 requirements to be fulfilled and they are: The regulators need a continuous feed of high pressure fluid (3000 psi). A Pilot signal to the regulator telling it what pressure to reduce the 3000 psi

to. A pilot signal (3000 psi) to the SPM, to lift it off its seat. An uninterrupted means of letting regulated fluid to the function (hose, shuttle,

valve). If you can be sure these requirements are met then it can only be 2 things:

the SPM or the function (ram operator, annular assembly, failsafe orconnector pistons).



Final Note:Remember that the manner and way you troubleshoot your controlsystem problem is vital to the rigs safety. How you derive the problemwill determine whether you require to make a surface repair, pull apod, pull the L.M.R.P. or pull the complete BOP stack. Therefore knowyour system well.



Troubleshooting: Leaks and Malfunctions

1) Leaks and MalfunctionsNormally, a fluid leak in the system is detected by watching the flow meter on thedriller's panel. If the flow meter indicates a fluid flow when no functions are beingperformed, or if it continues to run and does not stop after a function is performed,this generally indicates that there is a leak in the system.

Once you have determined that there is a leak, you should begin a check of thesystem to determine the location of the leak. 'Me first thing to do is to make athorough visual inspection of the surface equipment. You do this by carefullyexamining the hydraulic control manifold and accumulators to see if you can find abroken line in the system or a fluid leak at any of the fittings. If no leak is found, nextcheck the jumper hoses and hose reels to see that all connections are tight and thatno hoses are damaged. Sometimes a bad connection at a hose reel R13C junctionbox will result in a leak. Examine the connections carefully to be certain that theyhave a firm seat.

While at the hose reel, check the hose reel manifold to make certain that all of thevalves are in the centre position. Also, make certain that the needle valve to themanifold pressure supply shutoff is tightly closed. If this valve is left open when theRBQ junction box is connected to the reel, it will allow fluid pressure to be forcedback through one of the surface regulators and vent into the tank, thus indicating aleak in the system.

If you find this valve in the open position, then close it and check the flow meter tosee if the fluid flow has stopped.

If this procedure does not prove successful in locating and stopping the leak, youshould then return to the driller's panel to begin an item by item check of the system.

Upon returning to the driller's panel, change the pod selector valve to operate thesystem on the other pod.

For example, if you are operating on the blue pod, switch over to the yellow pod.This will tell you whether the leak is in one side, or both sides, of the system and willlet you begin to isolate the leak. If the leak stops when you change from the blue toyellow pod, then you know that the leak is located in the blue side of the system.

If the leak doesn't stop when you change control pods, then you know that the leakis either below the control pods or somewhere in the hydraulic control manifold.

Let's take a hypothetical example and say that the flow meter stopped when youchanged from the blue to the yellow pod. Ibis tells you that the leak is somewhere in



the blue side of the system. And, since you made a visual inspection of the surfaceequipment earlier, you now know that the leak is probably subsea. If conditionspermit, you should now change back to the blue pod, and try to isolate exactly wherethe fluid is leaking. Do this by blocking each function item by item, allowing plenty oftime for the function to operate. You should watch the flow meter very carefully whileblocking each function to see whether or not the leak stops. If the flow meter doesstop when a certain function is blocked, then you have isolated the leak, it issomewhere in that specific function.

Since you are not sure exactly where the leak is, you should next lower a TV camerainto the stack. Then unblock the leaking function and try to determine the exactlocation of the leak. The leak will show up in the water as a white mist seeping fromthe leak area. If the leak is coming from the pod, there is either a bad regulator orSPM valve in the pod. If the leak is bad enough, you can pull the pod and make thenecessary repairs.

Always use the schematic drawing to make certain you are working on the correctvalve and follow the repair procedures as outlined in the subsea manual.

If the leak is below the pod, and the problem is serious enough, you can either senda diver down to make the necessary repairs or pull the stack and repair the leak onthe surface. If the leak is not of a serious nature, you can simply leave that functionin the block position until the next time the stack is brought to the surface and thenmake the necessary repairs.If the flow meter did not stop when the pod selector was switched, or when allfunctions were blocked, you should check the master fluid return line to the tank- Ifthere is a fluid flow in this line, then one of the pilot valves or regulators is leaking.

First, check all pilot valves to make sure they are squarely in the block position orfully opened or closed. Sometimes a partially opened valve will allow fluid to leak bythe valve.

If the valves are all fully thrown, next disconnect the discharge line from each pilotvalve one at a time. If fluid exhausts from one of the valves after the discharge linehas been disconnected, then the valve is bad and should be replaced with a newone.

If the discharge lines on the pilot valves do not show and signs or leaks, thendisconnect the discharge lines on the regulators in the same manner checking for afluid discharge. Any fluid exhaust from the fluid return side of a regulator will indicatethat the regulator is bad and should be replaced.

Now, let's continue. For this example we will assume the system is operatingnormally and you push a button to perform a function. The flow meter begins to



measure the fluid but then continues to run and does not stop at the number ofgallons that is required to operate that function.

Remember, the key words here are "continues to run". It is important to note thateach time a function is operated it will not take exactly the same amount of fluidlisted on the fluid capacity chart. It can vary either way of the listed capacitynecessary to operate the function.

However, if the flow meter continues to show a fluid flow after the time required forthe function to perform, then there is a leak somewhere in that function.

One possible cause is foreign material or trash in the SPM valve seat causing thevalve to stay open and bleed fluid through the system. The best way to check fortrash is to operate the valve several times to try and wash out the foreign material.After operating the valve several times, observe the flow meter to see if the leak hasstopped.

Next, go to the hydraulic control manifold and check the one inch line in the otherjumper hose. This will tell you whether or not the shuttle valve for the function isleaking. If it is leaking, there will be a fluid return to the surface through the otherhose. In other words, the fluid will be flowing down through the blue pod, leaking bythe functions' shuttle valve, returning to the surface through the hose to the yellowpod. This fluid return will indicate a faulty shuttle valve. The leak can be stopped byblocking that function in the desired position and then leaving it until repairs can bemade later.

If these procedures do not stop the leak, the problem is most likely caused by eithera broken line, a bad SPM valve or a bad seal in the function. 1he best way todetermine which of these is the problem is to lower a TV camera to observe thesystem in operation. Any fluid leak should be easily seen as a white mist flowingfrom the leaking area. If the leak is in the pod, the pod can be retrieved to thesurface and repaired. If the leak is somewhere on the stack, you send a diver downand make the necessary repairs. Or, pull the stack, pressure test to locate the leakand then repair it on the surface.

Up until this portion we have been concerned with fluid leaks. Now we will look intosome possible malfunctions that can occur in the hydraulic fluid system.

The first thing we will consider is a slow reaction time in the operation of a function.For instance, if we push a button to operate a particular function that we know issupposed to take 22 seconds, but the operation takes 60 seconds, then we knowthat there is a malfunction somewhere in the system. This problem will most likely bycaused by: low accumulator pressure, a bad RBQ connection, or a partially pluggedpilot line.



First check the gauges to see if you have the proper operating pressures. If you dono have the required pressures, then check the pumps to make certain they areoperating properly, and check the fluid tank to make sure you have fluid in thesystem.

The next thing to check in looking for the cause of the slow reaction time is theaccumulators. Always make certain the shutoff valves between the accumulatorsand hydraulic control manifold is open. If someone has been working on the unit,they may have forgotten to reopen the valves when they finished.

If all pressures are good and you can find nothing wrong with the accumulators orthe hydraulic control manifold, next check all surface hose connections. If the RBQjunction boxes are not tightly seated, they can restrict the flow rate of the fluidthrough the connection and thus cause the function operate slowly.

If you have checked all connections and the pressure in the system is good, then thefinal thing to do is to pull the pod and check the pilot lines for sludge which may havesettled out of the hydraulic fluid. This can be accomplished by disconnecting eachline at the pod one at a time. As each line is disconnected, it should be flushed outby flowing new fluid through it.

Another malfunction you may encounter is no fluid flow meter indication when afunction button is pushed. This can be caused by one of the following problems: Noaccumulator or pilot pressure, the valve on the hydraulic control manifold did notshift, there is a bad SPM valve, or the flow meter is not working properly.

First, let's troubleshoot for no accumulator pressure or pilot pressure. The first thingto do when troubleshooting for this problem is to check all of the pressure gaugesthat monitor the system. Normally, these will give you an indication of where theproblem is located. Also, before leaving the driller's panel, press the 'Test Button" onthe panel to make certain that the lights in the function buttons are working properly.Sometimes these lights bum out and will not indicate the position of a function.

If you have been unable to solve the problem at the driller's panel, you will next haveto go to the hydraulic control manifold and begin looking there. The first thing to do isto double check the flow meter on the driller's panel. This is done by operating thefunction again while monitoring the flow meter on the hydraulic control manifold. It ispossible for the impulse unit which sends the flow meter signal to the driller's panelto malfunction. A bad impulse unit might not indicate a flow on the driller's panelwhen the fluid actually is flowing through the system.

Another way to check for a bad flow meter is the regulator gauge for that function.You can always tell whether or not a function operates by watching the regulatorpressure after you push the button to operate the function. If the pressure falls 300



to 500 psi after the button is pushed and then comes back up after the time requiredto operate the function, then you will know the function has been performedregardless of flow meter action.

Next, check the air regulator and the electrical supply to make certain that the properenergy is getting to the hydraulic control manifold. Check the fluid level in the tanksand check the pumps and their pressure switches to make certain they are in theproper operating condition. If the fluid in the tanks has run dry, the triplex pump willhave to be primed again before you can get the system back into operation.

Also, check all filters to make certain that they are not plugged with trash.

Also, check the nitrogen pre-charge in the accumulator and bottles. Ibis is done bybleeding the fluid from the bottles back into the tank. Then check each bottleseparately to make certain that each has the proper nitrogen pre-charge.

Next, we will give you some troubleshooting hints for what to do if the valve on thehydraulic control manifold fails to shift when the button on the driller's panel ispushed.

The first item to check is the air supply to the system. Too little air supply is one ofthe biggest causes of unsatisfactory operation and valve malfunction. Check the airgauge for excessive pressure drop. If the gauge shows less than 80 psi or anexcessive pressure drop during operation, the air supply is not enough to operatethe system satisfactorily.

people hang things over the handles and forget to remove them. These items cansometimes prevent the handles from turning.

If you can easily operate the valve manually at the hydraulic control manifold, thereare three other areas to check in troubleshooting this problem.

The button on the panel and the electric solenoids and power relays to the valve.

Check the valve itself to make certain that it is not faulty. The best way to do this isto simply replace the entire valve body assembly. If the function then works properly,you will know that the valve needs to be repaired.

If a plugged pilot or main fluid line is preventing a function from being performed, theonly way to solve the problem is to disconnect the hose at the pod, and flush the linewith clean fluid.

If there is a bad SPM valve preventing a function from operating, the only solution forthis problem is to pull the pod and replace the valve. Always be certain that you use



the schematic in the subsea manual to locate the correct SPM valve before makingany repairs. It's always better to double check to be sure you are replacing thecorrect valve than to run the pod back down and then discover that you replaced thewrong valve by mistake.



Operation of the Electrical Portion of the System

THREE POSITION FUNCTION

OPEN PUSH BUTTON

When the open button is pressed on a remote panel, the open solenoid on the HPU willbe energized to the open position. Air pressure will then pass through the normallyclosed solenoid to a 3 position air cylinder connected to the hydraulic panel manipulatorvalve on the hydraulic manifold. The manipulator valve is then shifted to the OPENposition. Opening hydraulic pressure pressurizes the pressure switch in the open pilotline turning on the open lamp for this function.

When the open button is released, the air solenoid valve will return to its normallyclosed position simultaneously venting air pressure off the air cylinder. If required, thepanel hydraulic valve may be shifted manually with the handle since air pressure is nolonger applied to the cylinder.

The lamps on a three position function use a combination of two pressure switches toturn on the proper lamps. When pressure is applied to the Open hydraulic line, theOpen pressure switch is activated. Voltage is applied to the Open lamp through thenormally open (N.O.) contact of the OPEN pressure switch and the normally closed(N.C.) contact of the CLOS

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