Chintan Trivedi

4th Sem,Mech. Engg.

Oil and Gas Well Control Equipment

Oil & Gas Exploration and Production

Exploration - Finding Oil & Gas. Oil & Gas fields are identified using seismic data which is obtained

from seismic surveys and its interpretation using computer modeling.

To confirm the interpretations of the seismic data, Drilling is done which is also called as exploratory drilling.

Based on well testing data & reserves estimates, if commercially viable, field development plans are made.

Includes development well drilling & completion. Oil and Gas production, processing & transportation. Work Over (Sick well repair jobs) rig deployment to maintain

production. Dry or unsafe well Abandonment.

Well Control

Balancing or preventing Formation Fluid entering into the well bore by controlling mud hydrostatic pressure.

Primary well control can be achieved using well control equipment.

Types of Well control

Hydrostatic Pressure - It is the pressure exerted by a static column of fluid by virtue of its density.

Primary well control - The maintenance of sufficient hydrostatic head exerted by drilling fluid to hold back the formation fluid pressure is termed as “Primary Well Control”.  

Secondary well control - It involves detection & safe handling of kicks so as to re-establish primary well control.

Tertiary well control - It involves the techniques used to control a blow-out once the primary & Secondary Controls are lost.This primarily involves a re-establishment of the secondary control system & subsequently establishing the Primary Control.

Kick & BlowoutKick Influx or flow of formation fluid into the well bore. Occurs if formation pressure is greater than Bottom

Hole Pressure exerted in the well bore. Blowout Uncontrolled flow of formation fluid at the surface

or subsurface. A result of uncontrolled kick. Can lead to oil well fire,loss of human life,Rig

equipment , environmental damage & disaster if not controlled professionally by blowout control experts.

Primary function -

Confines well fluid to the well bore.

Provides means to add well killing fluid to the well

bore.

Allows controlled volumes to be withdrawn.

Provides means to hang off drill string & shearing

of drill pipe if required.

Use of Well Control Equipment

Well control equipment used at Drilling / WOR rigs are -

Blow Out Preventer

BOP Control Unit

Choke Manifold & Kill Manifold

FOSV (Full Opening Safety Valve)

Inside BOP

HCR Valve (Hydraulically controlled valve) & Manual

Gate Valve

Types of Well Control Equipment

TO SHALE SHAKER

BLIND RAM

PIPE RAM

CHANGE OVER

SPOOL

CSG.BOWL

CASING

ANNULARBOP

DOUBLE RAM BOP

To DEGASER

WASTE PIT LINE

CELLER PIT

CHOKE MANIFOLD

KIL

L M

AN

IFO

LD

AS

SY

RISER NIPPLE

HCR Valve & Manual Gate Valve

When primary well control is lost, it becomes necessary to

close the well safely by some means in order to prevent

blowout.

The equipment designed to seal the well bore is called Blow Out

Preventer.

Types of BOP

Ram type BOP

Annular BOP

Blow Out Preventer

Ram type preventers seal the annulus by forcing two

front packing elements around pipe in the well.

Ram type preventer can only seal the corresponding

size of pipe in the well.

Variable rams can be used for different size of pipe.

Ram Type Preventer

Ram Type Preventer

Ram Block

Ram Shaft

Piston

Ram Change PistonLocking Screw

Can be closed on drill pipe, drill collar, casing pipe,

square & hexagonal kelly, tapered pipe, tool joint,

logging tool, wire line & open hole.

Annular preventer should be closed on open hole in

case of emergency only.

Annular preventer can be used for stripping operation

Annular Preventer

Annular Preventer

Upper Housing

Sealing Element

Sealing Ring

Adaptor Ring

Piston

Lower Housing

BOP control unit is a high pressure hydraulic unit used to close

/ open BOP during drilling & work over operations.

It provides sufficient operating fluid for BOP stack.

It includes accumulators, reservoir, piping, electric motor & air

driven pumps and manifolds to reduce closing time of BOP

functions.

High Pr. Fluid in accumulator bottles enables BOPs to be

closed in the event of power failure.

BOP Accumulator Unit

BOP CONTROL UNIT

BOP control unit consists of –

Accumulator bottles for storing pressurized fluid.

Hydraulic control fluid and its reservoir tank.

Charging system to pump hydraulic fluid into accumulator bottles.

Pressure regulating valves and an operating manifold to operate the BOPs , choke and kill valves.

Remote control panels for operating BOPs , choke and kill valves from remote locations.

SURFACE BOP CONTROL UNIT

Accumulator Bottles

Hi/Lo Bypass valve

Electric Starter

Pneumatic (Air) Pump

Electric Pump

Annular Regulator

Hydro-Pneumatic Pressure switch

Hydro-Electric Pressure switch

Manifold Regulator

4 way Valves

Guages

Remote panel for BOP Accumulator unit

RESERVOIR

MANIFOLD

Choke Manifold

Choke manifold is an arrangement of valves, lines and chokes to

control the flow of fluids from the annulus during the well killing /

well control process.

The chokes are used to create back pressure in kick control circuit

while killing the well to maintain Bottom Hole pressure(BHP).

Kill Manifold

Kill manifold is an arrangement of gate valves, lines and check valve.

Kill line provides a means of pumping into the well bore when the

normal method of circulating down through the kelly or drill pipe can not

be employed.

Manual Adjustable Choke

This type of choke creates a back

pressure with a stem and beveled

mechanism. Fluid is allowed to

flow through the seat or orifice.

Back pressure control is attained by

the degree to which the stem is

forced into the beveled seat or

extracted from it.

Mud Gas Separator

A mud/gas separator is an

essential equipment used on

the rig for removing high

percentage of gas from the

mud, which is coming out

from downstream of the choke

during gas kick.

BODY

UPPER SEAT

CRANK

BALL

LOWER SEAT

Advantages

Easier to install

Wire line tools can

be

lowered through it Disadvantages

Cannot be used alone

for stripping

FOSV/Kelly Cock

Release Rod

Rod lock Screw

Release Tool

Upper Sub

Dart Seat

Dart “O”Ring

Spring

Lower Sub

Inside BOP

Advantages

Can be used for stripping.

Can circulate through tool.

No back flow through tool. Disadvantages

Not easier to install.

Wire line tools cannot be

lowered through it.

HCR Valve

Gate Valve

In gate valve a blank plate is positioned across the

flow path to halt fluid flow. When the valve is

opened, the plate containing an orifice is positioned

across the flow path to allow fluid movement

through the orifice.

Gate Valve