Well Control Mechanisms

8/12/2019 Well Control Mechanisms

1/13


2/13


3/13

Failure to keep thehole full


4/13

Causes

High pulling speeds.

Mud properties withhigh viscosity and highgels.

Tight annulus BHA-hole clearance, orrestricted annulusclearance

Swabbing


5/13

Causes Cavernous or vugular

formations. Naturally fractured, sub-

normally pressured zones. Fractures induced by

excessive pipe runningspeeds.

Excessive pressures causedby breaking circulationwhen mud gel strength ishigh.

Lost Circulation


6/13

Causes

Drilling into an abnormal pressure zone.

Dilution of the drilling fluid.

Reduction in drilling fluid density due toinflux of formation fluids/gas.

After cementing while WOC. Cement losseshydrostatic pressure as is starts to set.

Insufficient Mud density


7/13

Drilling break Increase in flow rate

Pit gain

Pump pressure decrease/Pump strokeincrease

Well flows with pumps off


8/13

Blow outs Underground blow out

Blow Out Underground Blow Out


9/13

Primary Control-(Ph>Pf) Secondary Control-BOPS

Ram Preventers

Blind Ram

Shear Ram

Pipe Ram Annular Preventer

Tertiary Control-(Barite/Cement Plug)


10/13


11/13

Wait & Weight

Method

Kill well in one complete circulation

lowest pressure on the formation

Requires longest waiting time

DrillersMethod

First kick is circulated out then KMW is pumped

Can start circulation right away

Highest casing pressures for longest period

ill Methods


12/13

Bull heading

If High H2S gas influx

Pump Fluid to force formation fluid back into the

formation

Gas by pass

Volumetric

Apply if gas kick cannot be circulated out due to

migration

Drill string above the kick/out of the hole

Allow gas to expand

ill Methods


13/13

Documents

Well Control Mechanisms