CAD/ P&ID

CAD/ P&IDMuhammad Abdullah Shakeel

AbstractThe following report is to show the materials learned and experience gained by the intern in the one month spent with Engineering Department; Dragon Oil. It goes through the companys electric structure, general instrumentation principles and piping; design, manufacture and codes.

ACKNOWLEDGEMENTS

I wish to express my sincere gratitude to Mr. Ali Al Matar, Engineering Manager for providing me an opportunity to do my internship in Dragon Oil L.L.C

I sincerely thank Mr. John Kottappuram, Mr. Biju Menon & Mr. Abdullah Ghauri for their knowledge, guidance and support in carrying out this report.

ContentsIntroduction:5Electrical Engineering6Off Shore6On Shore6Hazards7Rating is as shown in figure 1;8Explanatory Example; (fig 2)8Electric Pumps:10Method 1;10Pump 2;10Pump 3;10Pump 4;11Pump 5;11Method 2;11Mechanism;11 Central Processing Facility (On Shore)12System;13Transformers;13Off Shore;13Generators;13Three Phase1414Distribution Board14Generators;15AC Generator:15DC Generator:16Engine Generators;17Instrumental Engineering:19Instrumentation in Petrochemical Industries;19Temperature Indicators;19Pressure Measurement;19Flow Meters;19Level Sensors;20Analysis Instruments;20Control System;21Function:21Control;21Separation;22Instrumentation diagram:23Legend:23Job:25Piping and Instrumentation Diagram (P&ID);29For processing facilities, it is a pictorial representation of;29List of P&ID items;29Identification and reference designation;30Symbols of chemical apparatus and equipment;31Instrumentation Symbols:32Practice 1;33Practice 2;34

Introduction:The following report is diving into three parts; Electrical, Instrumentation, CAD and Piping Engineering. It is formatted to include an introduction, body and conclusion in each discipline.

Electrical EngineeringElectrical Engineering is an important part of the petrochemical industry ensuring safe, reliable and economic production of oil and gas. Electrical engineers design, monitor, control and manage the electric power system that supplies power to the hundreds of high voltage motors and thousands of low voltage motors in the field. It is with those motors that the oil and/or gas could be extracted from the wells for processing at the plant. Electrical engineers also design, supervise, run and monitor instrumentation control consoles protecting personnel, machinery and equipment in the plant. (Electrical Engineering, 2015)

Off ShoreDragon Oil at present does not use pumps or motors to extract the oil from the reservoirs as the natural pressure acts like a self-pump, flowing out oil and gas. Thus electric engineering is not much used off shores other than lighting and other facilities for the engineers living there. It is produced by diesel generators on field.

On ShoreUnlike off shore, electronics play a vital role in Dragon Oil operations. Pumps are used to transfer crude oil to the jetty and all other facilities. The source of the electricity is primarily the Turkmenistan government, however there are generators installed on site which automatically start functioning in case of blackout or other failure.

HazardsThe difference between an oil industry and any other industry for the matter are hazards, normal equipment cannot be used as it poses great threat to the facility and workers. There are generally three classifications of hazard areas, Zone 0, Zero 1 and Zone 2.Hazardous areas are classified into zones based on an assessment of the frequency of the occurrence and duration of an explosive gas atmosphere, as follows:Zone 0: An area in which an explosive gas atmosphere is present continuously or for long periods;Zone 1: An area in which an explosive gas atmosphere is likely to occur in normal operation;Zone 2: An area in which an explosive gas atmosphere is not likely to occur in normal operation and, if it occurs, will only exist for a short time.

Various sources have tried to place time limits on to these zones, but none have been officially adopted. The most common values used are:Zone 0: Explosive atmosphere for more than 1000h/yearZone 1: Explosive atmosphere for more than 10, but less than 1000 h/yearZone 2: Explosive atmosphere for less than 10h/year, but still sufficiently likely as to require controls over ignition sources. (Hazardous Area Classification and Control of Ignition Sources, 2004)

To prevent disasters, special machines are used. Products are coded to their certification for use in particular types of environments.

Rating is as shown in figure 1;(Certification Definition, 2012)

Explanatory Example; (fig 2)

Classification of Equipment for use in potentially explosive atmospheres. (Fig 3)

Electric Pumps:The pumps used to transfer vary depending on the properties of crude oil, there are generally two ways of pumping.Method 1;

Pump 1; Settlement of wax and other substances on the inside surface is reducing. The nominal diameter of crude oil pipelines on production side. Screw Pumps are employed to flush the pipework with crude oil from the storage tanks on a regular base.Pump 2; High pressure Triple Screw pumps are installed as pipeline start-up pumps. These pumps are required when the main pipeline pumps cannot overcome the friction losses during start-up of a crude oil pipeline. Pump 3; Screw Pumps, series L4, are typically used as crude oil transfer pumps.

Pump 4; Large crude oil transfer pumps with big port sizes are not particularly suited to empty storage tanks completely. Smaller Screw Pumps, either in submerged design or dry mounted, must be used. With their excellent suction capability they remove heavy products with high viscosity and high solids content from the bottoms of the storage tanks. A special screw design along with a wide range speed control reduce the NPSHR values of these pumps to a minimum.Pump 5; Crude oil storage tanks must be cleaned on a regular base. Screw Pumps, handle these often high viscous residues consisting of heavy oil sludge and solids. Special Tungsten Carbide coating of the screws and Stellite coating on the liners protect the pumps against excessive wear and increase the service life considerably.Method 2;In some applications, a single pump is used to transfer the crude oil from storage to jetty/trucks/etc. Instead of using a starting pump to overcome friction, Voltage is fiddled with to create inertia of motion. This takes a little longer to start the pump but saves a lot of electricity.

Mechanism;

There are many types of pumps with different mechanisms, however the power the pump produces is given by the equation;

Where p is the change in total pressure between the inlet and outlet (in Pa), and Q, the volume flow-rate of the fluid is given in m3/s, is the pump efficiency. (Pumps, 2015)

Central Processing Facility (On Shore)

GRID35 KV

Transformer35 -> 6KV

Distribution Board6KV -> 400V

Load 230v 230v 400vCentral System Pumps Other Facilities

System; Electricity is provided by the Turkmenistan government. High voltage is received by the grid. This voltage is however too high to run machinery; Transformers are used to cut down voltage levels for safe use, in this case from 35Kv to 6v. The 6000 Voltage then goes to the distribution board where it further decreases to 230 Volts to run equipment such as lightning, heaters etc. The raw 400V is used to run pumps. (Oil Transfer). In case of power blackout, Backup generators are present with logic gates which monitor the voltage activity and turn on the generators accordingly.

Transformers; Electrical transformers are used to "transform" voltage from one level to another, usually from a higher voltage to a lower voltage. They do this by applying the principle of magnetic induction between coils to convert voltage and/or current levels. (Transformers, 2014)

Off Shore;As of now, there is no electricity connection between offshore and grid. Individual platforms have independent diesel-powered generators running them. Generators;There are multiple ways of producing electricity, for instance; Wind turbines, Thermal turbines, geothermal energy, solar energy, Fossil fuels. There are different types of generators as well which come under a) Alternating current generators and b) Direct current generators.

Dragon Oil uses diesel powered generators as it is economic, reliable and efficient. It functions as follows; FuelGenerator EngineAlternator

Three Phase

Distribution Board

Generators;

AC Generator: Generators have two windings components, one is the armature, which generates the electricity through electromagnetic induction, and the other is the field component, which creates a static magnetic field. When the armature moves relative to the field, a current is induced due to the flux change around it. The current is known as the induced current and the voltage which drives it is known as electro-motive force. The repetitive relative motion required for this process is obtained by rotating one component relative to the other. The rotating part is called as the rotor, and the stationary part is called the stator. Either armature or the field can operate as the rotor, but mostly the field component is used in high voltage power generation, and the other component becomes the stator.

DC Generator: Slight change in the configuration of the contact terminals of the armature allows an output that does not change the polarity. Such a generator is known as a DC generator. The commutator is the additional component added to the armature contacts.The output voltage of the generator becomes a sinusoidal waveform, because of the repetitive change of the polarities of the field relative to the armature. The commutator allows the change of the contact terminals of the armature to the external circuit. Brushes are attached to the armature contact terminals and slip rings are used to keep the electrical connection between the armature and the external circuit. When the polarity of the armature current changes, it is countered by changing the contact with the other slip ring, which allows the current to flow in the same direction.

Engine Generators;Most engine generators run on either gasoline, diesel fuel or propane. Besides the relative cost difference between the three fuel types, the operating principles between them are the same. The primary difference between various generators is their output capacity.

Very small portable generators are available, which would not produce enough power to effectively support a household electrical system but are perfect for operating single pieces of equipment. It may be that the renewable energy system doesn't have sufficient capacity to simultaneously power the house and a specific piece of equipment or machinery. It wouldn't be cost effective to expand the alternative system if the equipment in question is rarely used, or it may be that a specific piece of equipment needs to be operated for a short time at a remote location. A portable generator would fit perfectly into such a situation.

A mid-sized generator that may be too small to power a full household electrical system operating at capacity can still provide supplemental power to charge batteries when the alternative system is under-performing. Such a generator could be attached only to specific essential power circuits, allowing non-essential loads to go without power until the batteries are recharged. This allows for reliable back-up power with a much smaller investment than a stand-alone capable generator would require, although the electrical system may not be fully operational at all times.

For systems where partial-capacity operation is not a viable (or desirable) option, engine generators are available at very high output capacity. While the alternative system may provide sufficient power under most conditions, with a full-capacity backup generator there is no concern about losing power in any situation. These large generators are also commonly found in hospitals, where vital life-support and other medical equipment must be operational even when grid power fails. (ABS Alaskan, 2015)

Instrumental Engineering:

Instrumentation engineering is the engineering specialization focused on the principle and operation of measuring instruments that are used in design and configuration of automated systems in electrical, pneumatic domains etc.

Instrumentation in Petrochemical Industries;

Temperature Indicators; The measurement of temperature is a vital part of instrumentation in petrochemical industries. Platinum Resistance Temperature Detectors (RTD's) are often used for their excellent temperature response. Thermocouples are used in locations that need a more durable sensor.

Pressure Measurement; We use a Pressure to Current converter (P/I converter) in petrochemical industries to measure the pressure developed by Liquefied Petroleum Gas (LPG), crude oil, petrol, and various other petroleum byproducts. In the P/I converter, the indicated pressure can be a digital or an analog form. The main advantage is that it can be directly shown on the control panel in the control room. This is true for temperature measurement also.

Flow Meters; Because refined oil is volatile, it is important to know the quantity of oil being transported at numerous points along the pipeline. This requirement also holds for natural gas. Flow meters are generally of vortex, Positive Displacement (PD), Differential Pressure (DP), Carioles, and ultrasonic varieties.

Level Sensors; Petroleum and natural gas industries need very accurate level measurement. Besides traditional technologies like differential pressure level meters, radar, magnetostrictive, and magnetic float are also used extensively. One of the problems with a significant number of technologies is that they are installed through a nozzle and are exposed to products. This can create several problems, especially when retrofitting new equipment to vessels that have already been stress relieved, as it may not be possible to fit the instrument at the location required. Also, as the measuring element is exposed to the contents within the vessel, it may either attacked or coat the instrument causing it to fail in service. One of the most reliable methods for measuring level is using a nuclear gauge, as it is installed outside the vessel and doesn't normally require a nozzle for bulk level measurement. The measuring element is installed outside the process and can be maintained in normal operation without taking a shutdown. Shutdown is only required for an accurate calibration.

Analysis Instruments;Industrial chromatographs are generally use d in olefin processing in the petrochemical industry. Continuous gas analyzers are also widely used.

Control System;There are three main classifications of control systems. First being process control which is used around the clock. ESD; Emergency shutdown runs simultaneously to prevent damage to the system. ESD does not completely shut down the platform. It just turns off operations in the section where the problem occurs.Fire and Gas/ Complete Shutdown; this happens in high chances of a gas or oil leak. Actuators are installed alongside the pipeline which monitor the gas levels.

Function: All these measuring instruments are connected to the control center via special wires. The wires run above the pipelines to the control center. Control;There are many types of valves used for controlling the flow in the pipes. A ball valve is used for complete shut off (0 or 1). It opens and closes at 90 degrees and is powered by hydraulic oil or sometimes manually. For control, a globe valve is used, it can be operated from all ranges 0 to 100% as shown in diagram; The measurements are measured in milli amperes for example 4 to 20mA with 4 being 0% and 20 being 100%. All these values go to the control center first and are analyzed by the engineers. The engineers can then further control the valves and other equipment accordingly.A pneumatically actuated ball valve operates automatically, it opens and closes approximately one-half to one second depending of actuator model / type. Pneumatic ball valves are designed to operate using high pressures of air or hydraulic fluid. Non compressible liquids have to be used in such applications.

Separation;Instrumentation are used the most used while separation. Temperature in tanks, pressure, everything is monitored. This information is connected to main servers and can be seen real time anywhere. For instance Dragon Oil can view the pressures and operating values of their plant in Turkmenistan.

Instrumentation diagram:These diagrams are used to display the layout of the piping and instruments used. Special symbols are used for different components. Legend:

A typical Instrumentation looks like this:

Job:An instrumentation and control engineer is required to;1. Design and develop control systems2. Maintain the existing control systems3. Manage the control systems4. Collaborate with design engineers, purchasers and other staff members involved in the production processes5. Manage projects within the given restraints including cost and time6. Troubleshoot7. Ensure that the instruments comply with health and safety regulations8. Ensure that quality standards are maintained9. Provide consultancy support

The main purpose of instrumentation engineering is ensuring stability, reliability, safety and continuity of petroleum components. It also works with the goal of improving productivity and optimization. These engineers design, develop, maintain and manage the instruments and instrumentation systems.

Process control may either use feedback or it may be open loop. Control may also be continuous (automobile cruise control) or cause a sequence of discrete events, such as a timer on a lawn sprinkler (on/off) or controls on an elevator (logical sequence).

A thermostat on a heater is an example of control that is on or off. A temperature sensor turns the heat source on if the temperature falls below the set point and turns the heat source off when the set point is reached. There is no measurement of the difference between the set point and the measured temperature (e.g. no error measurement) and no adjustment to the rate at which heat is added other than all or none.

A familiar example of feedback control is cruise control on an automobile. Here speed is the measured variable. The operator (driver) adjusts the desired speed set point (e.g. 100 km/hr) and the controller monitors the speed sensor and compares the measured speed to the set point. Any deviations, such as changes in grade, drag, wind speed or even using a different grade of fuel (for example an ethanol blend) are corrected by the controller making a compensating adjustment to the fuel valve open position, which is the manipulated variable. The controller makes adjustments having information only about the error (magnitude, rate of change or cumulative error) although settings known as tuning are used to achieve stable control. The operation of such controllers is the subject of control theory.

A commonly used control device called a programmable logic controller, or a PLC, is used to read a set of digital and analog inputs, apply a set of logic statements, and generate a set of analog and digital outputs.

For example, if an adjustable valve were used to hold level in a tank the logical statements would compare the equivalent pressure at depth set point to the pressure reading of a sensor below the normal low liquid level and determine whether more or less valve opening was necessary to keep the level constant. A PLC output would then calculate an incremental amount of change in the valve position. Larger more complex systems can be controlled by a Distributed Control System (DCS) or SCADA system.

The above flow chart describes how the control system functions. As seen, the system makes the change in the component which cam either set to automatic or manual.

As shown, the sensor reads the water level/temperature, these readings are in millivolts which are preset. They are then decoded by the signal converter into numerical values and displayed on the controller output. The engineer in the control room makes the decision of opening or closing the valve and hence its done. This can be automated by software also.

CAD/ P&IDMuhammad Abdullah Shakeel

Piping and Instrumentation Diagram (P&ID);A piping and instrumentation diagram/drawing is a diagram in the process industry which shows the piping of the process flow together with the installed equipment and instrumentation.P&IDs play a significant role in the maintenance and modification of the process that it describes. It is critical to demonstrate the physical sequence of equipment and systems, as well as how these systems connect. During the design stage, the diagram also provides the basis for the development of system control schemes, allowing for further safety and operational investigations, such as a Hazard and operability study commonly pronounced as HAZOP.For processing facilities, it is a pictorial representation of; Key piping and instrument details Control and shutdown schemes Safety and regulatory requirements Basic start up and operational informationList of P&ID items; Instrumentation and designations Mechanical equipment with names and numbers All valves and their identifications Process piping, sizes and identification Miscellanea - vents, drains, special fittings, sampling lines, reducers, increasers and swaggers Permanent start-up and flush lines Flow directions Interconnections references Control inputs and outputs, interlocks Interfaces for class changes Computer control system Identification of components and subsystems delivered by

Identification and reference designation;

Based on Standard ANSI/ISA S5.1 and ISO 14617-6, the P&ID is used for the identification of measurements within the process. The identifications consist of up to 5 letters. The first identification letter is for the measured value, the second is a modifier, 3rd indicates passive/readout function, 4th - active/output function, and the 5th is the function modifier.

Symbols of chemical apparatus and equipment;

PipeThermally insulated pipeJacketed pipeCooled or heated pipe

Jacketed mixing vessel (autoclave)Half pipe mixing vesselPressurized horizontal vesselPressurized vertical vessel

PumpVacuum pump or compressorBagGas bottle

FanAxial fanRadial fanDryer

Packed columnTray columnFurnaceCooling tower

Heat exchangerHeat exchangerCoolerPlate & frame heat exchanger

Double pipe heat exchangerFixed straight tubes heat exchangerU shaped tubes heat exchangerSpiral heat exchanger

Covered gas ventCurved gas vent(Air) filterFunnel

Steam trapViewing glassPressure reducing valveFlexible pipe

Instrumentation Symbols:

Practice 1;

Practice 2;

Made with Lucid Chart.