11/25/13 INSIDE BOP

apirigroup.com/inside_bop.html 1/5

34. INSIDE BOP

34.1 FUNCTION

There are several pieces of equipment in addition to the primary blowout prevention equipmentthat are sometimes necessary to control a kick. The equipment which

furnishes closure inside the drill string is called an "INSIDE BLOWOUTPREVENTER". They are installed on the top or inside the BHA with the purpose to provide a means of

closing thestring for well control or even to permit to repair/replace some tools.

Inside BOP

- Manufacture specificationsInside BOP are manufactured according to API 6A (and API 7 for the connections)The relevant ISO standard is the 10423 Spec.

34.2 TYPES OF INSIDE BOP

DROP-IN VALVE

FLOAT VALVE

GRAY FLOAT VALVE

SAFETY VALVES

DROP-IN VALVE

- Components:

Landing Sub

installedin the drilling string;

Check valve: pumpdown or drop-in typedropped inside the stringand latches inside thelanding sub used forstripping or before to cutwith shear rams.

Retrieving Tools

areused if the check valve iswireline retrievable.

Main manufacturer are:

- HYDRIL

- SMF

11/25/13 INSIDE BOP

apirigroup.com/inside_bop.html 2/5

- HYDRIL DROP-IN VALVE Checkguard

Developed in the 1930s (market pioneer), Installed in the lower end of the drill string above the bit to prevent backflow

- Configurations and API specification5 configurations

#19 1 3/16" I.D. thru bore

#27 1 11/16" I.D. thru bore

#35 2 3/16" I.D. thru bore

#43 2 11/16" I.D. thru bore

#48 3" I.D. thru bore

Conforms to API, specification 7

- Working Principles

- Installing Checkguard valve

Checkguard valve is installed as needed. Remaining top side, it is not subject to constant wear asmany downhole valves are. Abrasive wear on typical drill pipe float valves

results in frequentreplacement and can prevent closure. Only the Checkguard landing sub is installed as the drill string is run.

When control is needed, the valve is pumped down the drill string where it latches automatically inthe landing sub.

- Pumping down Checkguard valve

Downward flow ar\eas are maximized for high flow capacity and long life.The check valve sits in the landing sub in the replaceable landing sleeve, latching positively. The

sleeve has recessed areas into which the check valve packer seals.

- Close Checkguard valve

Checkguard valve seals pressure up to 15,000 psi.Yet it is lightweight and easily handled.The ball closes against upward pressure.

- Retrieving Checkguard valve

It is wire-line retrievable. Wire line retrievable, eliminating the need to trip the drilling string.Retrieval can also be accomplished after tripping out the drill string. In this

illustration, the retrieving tool unlatches the check valve and lifts it to the surface.

FLOAT VALVE

Float valve may be considered an INSIDE BOP. Basically a flapper or poppet type check valve that is installed in the bit sub to prevent back flowduring connections. It allows

circulation only in one direction.

- FVR Float Valve

Float Valve

Plain Flapper and Vented Flapper

11/25/13 INSIDE BOP

apirigroup.com/inside_bop.html 3/5

GRAY FLOAT VALVE

Always on the rig floor ready to be installed, thehold-open type has the back pressure valvepinned in an open position so that the valve canbe installed when mud is flowing.

The pin is removed after installation to allowclosure.

SAFETY VALVES

Kelly Cock

Rigs with TOP DRIVE

Actuator Types

- Kelly Cock

The kelly cock is a safety valve placedabove the kelly (UPPER KELLY COCK) and below the kelly (LOWER KELLYCOCK). Its basic purpose is to provide a means of closing the

string should the swivel, hose, or stand-pipe leak or rupture under conditions of a threatened blowout. This arrangement permits these items to be repaired or replaced. A

special wrench to operate the kelly cock is required and must be taken in a readily a ccessible place known to every crew member.

11/25/13 INSIDE BOP

apirigroup.com/inside_bop.html 4/5

- Rigs with TOP DRIVE

Rigs with TOP DRIVE have two valves: A manual one on bottom part (lower kellycock) and one on the top remotely operated (upper kelly cock).

- Actuator Types

11/25/13 INSIDE BOP

apirigroup.com/inside_bop.html 5/5