Dore-1 Abandonment Prog

WOODSIDE ENERGY LTD

ABANDONMENT PROGRAM

DRILLING & COMPLETIONS INTERNATIONAL

DORE-1

MAURITANIA ABANDONMENT PROGRAM

Well Name: Dore-1 Block: 4 Permit: PSC-Area B

Vertical Exploration Well Rig: Stena Tay

Dore-1 P&A Program rev0

WOODSIDE ENERGY LTD

ABANDONMENT PROGRAM

DRILLING & COMPLETIONS INTERNATIONAL

DORE-1

CONTROLLED DOCUMENT

Title: Abandonment Program : Dore-1 A.B.N. 63 005 482 986

DOCUMENT INFORMATION DRIMS#:

Rev: 1

DRIMS Classification (if applicable): MAU/WEM/020/v0

Prepared by: Fraser Lawson

Date:

Signature:

Supervised by (if applicable):

Date:      

Signature:

Approved by: Graham Singleton

Date:      

Signature:

CONCURRENCE Name Grant Lintern

Group

Date

Drilling & Completions

     

Signature

REVISION HISTORY Revision 0

Description Draft

Date 27.01.06

RELEASE STATEMENT

REVIEW STATUS

(Check one box only)

(Check one box only)

Unclassified (Shared without Restrictions)

Restricted (Freely Shared within Woodside and Associated Companies)

Confidential (Shared With Selected Personnel)

Prepared by

Approved by

Fraser Lawson

Graham SIngleton

PREPARED (Check one box only)

Review Period 1 Year

By WEL

Review Period 3 Years

For WEL

Under PO/Contract No:      

Review Not Required

Most Confidential (Strict Need-to-Know Basis)

Woodside Energy Ltd. (Woodside) owns or is responsible for the copyright in this document. All rights reserved. Neither the whole nor any part of this document may be reproduced, stored in or transmitted in any form by any means (electronic, mechanical, reprographic, recording or otherwise) without the prior written consent of Woodside.

Dore-1 P&A Program rev0

1

WOODSIDE ENERGY LTD

ABANDONMENT PROGRAM

DRILLING & COMPLETIONS INTERNATIONAL

DORE-1

INTRODUCTION The Dore-1 exploration well was drilled to a total depth of 2833m BRT (Stena Tay). The well will be abandoned with the wellhead left in place at the seabed.

2

OPERATIONS SUMMARY After the drilling and wireline logging program has been completed, the well will be abandoned with a 9 5/8” cement retainer & cement plugs. The cement retainer will set ion wireline above the 9 5/8” casing shoe and pressure tested. Cement will be squeezed below the 9 5/8” shoe and a 180m balanced plug set above the retainer to provide a permanent barrier. A 100m near seabed cement plug, set on a high viscosity pill will provide a second permanent barrier. (Refer to Proposed Abandonment Schematic). After setting the surface cement plug, the subsurface BOP will be unlatched and recovered. After installation of a corrosion cap and completion of the sea bed survey by the ROV, the rig will be released off Woodside contract. There is no requirement to cut casing or recover the wellhead. GENERAL INFORMATION Location Co-ordinates Well type Concession Situation Water Depth Well TD Well fluid Top HC Btm HC

: : : : : : : : : :

Dore-1 Easting 331 466.46 m, Northing 1 987 370.24 m Exploration PSC- Area B (block 4) Mauritania 385.4 m (LAT) 2388m BRT 1.52 sg SBM None BRT, (provisional) None BRT, (provisional)

All BRT rotary table depths in this document are referenced to the Stena Tay rig (air gap: 38.4m).

Dore-1 P&A Program rev0

3

WOODSIDE ENERGY LTD

ABANDONMENT PROGRAM

DRILLING & COMPLETIONS INTERNATIONAL

DORE-1

SEQUENCE OF OPERATIONS General Following completion of TD electric logging perform the following:

3.1

RIH and set 9 5/8” Weatherford cement retainer on electric line at +/- 1960m. Correlate with CCL. Do not set in shoe track or close to casing connection. POOH to surface.

3.2

Once wireline above BOPs close shear rams and pressure test plug to 750psi /15 mins (approximately 500psi above FIT with 1.52sg mud). Rig down Baker Atlas.

3.3

RIH cement retainer stinger assembly on 200m 3 ½” drill pipe with 5” drillpipe to surface.

3.4

Tag and stab into retainer.

3.5

Pump down drillpipe and establish injectivity pressure and rate with cement unit. Plot pressures against volumes pumped and report observed LOT value as injection is initiated. Squeeze 10 bbls SBM below retainer to confirm injectivity. Minimum injectivity rate is 0.5bbl/min. Limit surface press to 3000 psi.

3.6

Pull out of cement retainer with stinger. Pick up 10-20ft above retainer.

3.7

Close annulus and take returns up choke line, maintaining approximately 500psi backpressure.

3.8

Pump 30bbls 1.68sg MUDPUSH II spacer ahead.

3.9

Mix and pump 65 bbls 1.9sg Cement Slurry.

3.10 Pump 5 bbls MUDPUSH II spacer behind slurry. 3.11 Displace with 1.52sg SBM until 20 bbls of MUDPUSH II spacer pumped ahead is in annulus, ie 10bbls of MUDPUSH II spacer left in stinger. 3.12 Strip in and sting into cement retainer. 3.13 Bleed down annulus pressure to approximately 100psi. 3.14 Squeeze 10 bbls Mudpush and 26 bbls cement slurry below retainer such that the base of cement plug 1a is calculated to extend to 2050m. 3.15 Open annular, sting out of retainer and spot remaining 39 bbls as a 160m balanced cement plug from 1960m – 1800m. Underdisplace plug as advised by Cemcade (10 bbls provisional). 3.16 Pull back 200m above TOC and circulate clean. Drop foam ball to clean drill pipe. 3.17 Close annular and pressure test retainer 200 psi above final injection pressure / 10 mins to confirm closed. 3.18 Pull back to 700m. 3.19 Spot Hi Visc SBM at 1.52sg from 700 to 600 m. 3.20 Pull back to 600m. 3.21 Circulate kill/choke and booster lines to seawater. 3.22 Displace SBM from well with hi-vis pill and seawater at maximum rate as per BHI displacement plan. 3.23 Flow check well 30 minutes. Estimate still 90 psi overbalance assuming 1.52 SG pore pressure at TD

Dore-1 P&A Program rev0

WOODSIDE ENERGY LTD

ABANDONMENT PROGRAM

DRILLING & COMPLETIONS INTERNATIONAL

DORE-1

3.24 Mix and displace balanced cement plug 2 from 600 to 500m. Use drill water spacers, underdisplace plug as per Cemcade (3 bbls provisional). 3.25 Pull back to BOP and circulate clean. Drop foam ball to clean drill pipe. 3.26 Function test rams and annulars. 3.27 Wash and jet the wellhead/BOP's clean. Leave wear bushing in place. 3.28 POOH. 3.29 Hold rig floor safety meeting. R/U rigfloor for pulling riser. 3.30 Pull Riser/BOP as per Stena procedures. 3.31 While observing with ROV, unlatch BOP and pull same clear from wellhead. Recover VX gasket. 3.32 Move rig 50m away from wellhead. 3.33 Continue pulling riser as per Stena’s procedures. 3.34 ROV installs corrosion cap & completes seabed survey. 3.35 Continue with rig demob operations. Blow down bulks. 3.36 Prepare signed Well Acceptance Criiteria (Drilling Programme Appendix F) and signed Statement of Facts for remaining bulk commodities. Scan and send both documents to town. Ops DE in town will prepare final abandonment schematic

Dore-1 P&A Program rev0

WOODSIDE ENERGY LTD

ABANDONMENT PROGRAM

DRILLING & COMPLETIONS INTERNATIONAL

DORE-1

Appendix A : Proposed Abandonment Schematic

Dore-1 P&A Program rev0