11/12/2012 BOP Shear ram testing #1

Wells Process Safety Symposium

Hans Flikkema

What happened:

Master bushings suddenly blew out of

rotary table while jetting wellhead with

seawater.

INCIDENT ALERT

NM - Master Bushings Blown out Out (10.06.10)

What actions taken to prevent recurrence:

Operating practices under total losses

reviewed and recommended changes

have been implemented (next slide) Modified Elevator

What caused it:

Poor accepted practices and procedures!

Well was on total losses since acid stimulation,

over 60 hrs prior, and annulus was

continuously being filled at 8 bbl/min. The

cumulative fill rate was increased to 13

bbl/min to jet wellhead. Evidently, a small

gas bubble at the unknown fluid level

became trapped after pump rate was

increased, then expanded to vertical section

and unloaded seawater exponentially.

What was the result:

Inner bushings and master bushings blew

out of rotary, landing near the AD who was

standing 2 meters away. BOP was closed

and gas bubble bullheaded back to

formation.

MASTER BUSHING

PIN

MASTER

BUSHINGS

BUSHING INSERT

Synergi Case

1542

Changes in operating practises

implemented:

• All post stimulation operations prior to

completion will be carried out with

rotating head installed and activated as

extra barrier

• Post stimulation completions will be

run with sump packer and plug in

tailpipe installed to isolate the reservoir

prior to running the top completion with

multiple control lines.

• In case installation of sump packer is

not possible (multiple zone

completions) the well will be stimulated

after the completion has been installed

through application of QCAJ liners.

• Well designs and relevant operating

procedures have been amended

accordingly.

INCIDENT ALERT

NM - Master Bushings Blown out Out (10.06.10)

Modified Elevator

MASTER BUSHING

PIN

MASTER

BUSHINGS

BUSHING INSERT

Synergi

Case 1542

13-5/8” BOP Shear Ram testing Charles Rowan February and March 2011

OBJECTIVE:

TO VERIFY SHEAR RAM PERFORMANCE WITH THE

BOP’s, RANGE OF TUBULARS (4-1/2”, 5-1/2”, 7”)

AND CONTROL LINE CONFIGURATIONS TYPICALLY

USED IN MAERSK OIL QATAR.

11/12/2012 BOP Shear ram testing #4

11/12/2012 BOP Shear ram testing #5

7” TUBING

11/12/2012 BOP Shear ram testing #6

+/- 6”

Flat pack

squeezed

by side

packers.

As these pictures show then the control lines will not

necessarily be cut 100% and can then cause the rams to

leak on the following pressure tests.

Only 25% (4 out of 16) of the initial

pressure tests were successful. 11/12/2012 BOP Shear ram testing #7

ISR

Body & Blades: 350 deg F / 35% H2S

Elastomers: 250 deg F / 5% H2S & 350 deg F / 35% H2S (Top Packer only)

13-5/8” 10M U max shear OD 7.53”

Calculated shear pressure to shear 7” 23# L-80 w/ Large Bore Bonnets

and Tandem Boosters 2136 psi (No well pressure).

11/12/2012 BOP Shear ram testing #8

Follow up action

• ISR type rams only because they shear/seal more

effectively than SBR type rams .

• 4 ram stack up now standard. –It allows for extra blind

ram on top.

• Completion practises adapted;

• Always us RTH when losses.

• Run sump packer with plug prior to running completion (single

zone stimulated completions)

• Stimulate well after completion has been installed ( multiple

zone completions)

11/12/2012 #9 BOP Shear ram testing

BOP EQUIPMENT changes

CAMERON 13-5/8” 10M TYPE U WITH LARGE BORE

BONNETS AND TANDEM BOOSTER ARRANGEMENT.

CONFIGURATIONS IN TODAY’s OPERATION:

ANNULAR – DOUBLE U – DRILLING SPOOL – SINGLE U

ANNULAR - DOUBLE U – DOUBLE U

CONFIGURATION IN FUTURE OPERATIONS FOLLOWING TEST:

ANNULAR – SINGLE U - DOUBLE U – DRILLING SPOOL – SINGLE U

ANNULAR – DOUBLE U – DOUBLE U

ISR RAMS only

Extra set of blind rams on top of shear rams

11/12/2012 BOP Shear ram testing #10