recovery from hydrate plug during well control incident .... novel coil tubing.pdf · recovery from...

Recovery from Hydrate Plug During Well Control incident using Coiled Tubing

Abdullah Eshtewi

Completions Engineer

DRIMS # 7594942

Sep 2011

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Agenda

• Overview.

• Themes.

• Where ? Why ?

• Coiled Tubing rig up.

• Hydrate Milling operation.

• Coiled Tubing abrasive cutting and perforation.

• Choke and Kill line blockage.

• Lessons learned.

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Larsen-1 Overview

• Production casing ran and cemented with the 9 5/8” casing shoe set at 2829m.

• On February 1st 2010, drilled into gas bearing formation and a gas kick was recorded at 4602m.

• Well was shut in and the formation 100m below the shoe broke down - under ground blow out.

• Attempts to control the well by setting Barite plugs were unsuccessful.

• Well control operations were complicated by hydrate blockage in the C&K lines and drill pipe.

• The well was P&A on March 18th, 2010, after 38 days to control the well.

This presentation will focus on challenges encountered during Coiled Tubing operations

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Themes

1. Contingency planning.

• Think a head to cater for escalation.

2. Problem solving.

• Require open minded and experienced team to adopt unconventional solutions.

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Where ?

Larsen 1

• Larsen-1 is located on the Exmouth Plateau.

• 1200m water depth.

• Deepest well for woodside in the area.

• New built Semi-Sub “Maersk Discoverer” drilling rig.

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Sequence of Events Prior Intervention

• Took a kick “under ground blow out”.

• Pumped 2 x Barite plug (unsuccessful).

• Blocked C&K.

• Ran in hole E-line to sever pipe, tag shallow at 1165m.

Start Planning Coiled Tubing “NOW”

Better to start planning early

/32 4606m

9 5/8” 2829m

6 ¾

” B

HA

5”

DP

5.87

5”

DP

1279.2m BOP Shut in on Annular

Choke Line No Circ

Boo

st L

ine

OK

Riser

E line BOP

5”

HW

DP

Loss zone

2 x FOSV

• Under ground blow out.

• Well shut in.

• Stuck BHA.

• C&K lines plugged.

• DP plugged.

• Trapped pressure below BOP.

Status Schematic

Kill Line No Circ

Gas cross flow

• No Tool access • No circulation path • Pressure build up be low BOP

Rig up Coiled Tubing “NOW”

Pressure build up

below BOP

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Plan of attack

• Rig up Coiled Tubing.

• Mill Hydrate plug.

• Sever the DP, pump barite and cement plug to isolate lower zone.

• Sever the DP and pump cement plug to isolate the shoe.

• Remove trapped gas below BOP.

• Clear C&K lines using CT

4606m

9 5/8” 2829m

6 ¾

”B

HA

5” DP

5.87

5”D

P

Boo

st L

ine

OK

Riser

E line BOP

5” HW

DP

2 x FOSV

Trapped gas

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0.6m

Rigging up Coiled Tubing

• FOSV => 2 ¼” ID, changed out to 2 ¾” ID

• Only few CT tools fits through this restriction

• Drill Pipe elevators Not suitable to rig up CT

E-Line R/U

Upper Tension frame

45’ bails

DP elevator

FOSV

Lesson learned: Up front planning for well control operations

/32 1.8m


king size elevator

Used D.P elevators as C plate

10cm O ring is required

Up front planning for well control incidents

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~25m

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• CT hoses did not reach Injector head.

Up front planning

• New built rig.

• CT rig up on computer model.

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Plan of attack




• Sever the DP and pump cement plug to isolate the shoe.



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Milling Hydrate - Design

Key component:

• Hydrate suppression mud “HSM”

Mobilized all the MEG on the east cost !

• Mill design

• Motor performance

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Milling Hydrate - Operation

Operations:

• RIH and tagged top of plug at 1156m.

• Displaced to HSM.

• Milled through Multiple layers of Hydrate with pressurized gas pockets in between.

• Continued RIH C.T and drifted the pipe.

• Encountered losses.

• Set a DP plug.

• Multiple hydrate plugs rather than one solid plug • Huge quantities of MEG were required

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Plan of attack

• Rig up Coiled Tubing

• Mill Hydrate plug

• Set PSP plug to stop losses


• Sever the DP and set cement plug on shoe



Requirment to understand well behaviour and performance of barite/cement plugs

Temperature Log

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20

40

60

80

100

120

140

24002500

26002700

28002900

30003100

32003300

34003500

36003700

38003900

40004100

4200

Depth (m)

Tem

pera

ture

(deg

C)

Drims

Shoe Loss zone

Temperature Log Analysis

Run 1 - PSP plug in the string, T log after ~ 6hrs Run 2 - Sever the DP and pump ~400bbls 1.25sg “dynamic kill: followed by 90 bbls barite plug Run 3 - T log after ~ 8hrs Run 4 - After Cement plug

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20

40

60

80

100

120

140

24002500

26002700

28002900

30003100

32003300

34003500

36003700

38003900

40004100

4200

Depth (m)

Tem

pera

ture

(deg

C)

Drims

Shoe Cut at 4245m

Loss zone


Run 1 - PSP plug in the string, T log after ~ 6hrs Run 2 – Sever the DP and pump ~400bbls 1.25sg “dynamic kill: followed by 90 bbls barite plug Run 3 - T log after ~ 8hrs Run 4 - After Cement plug

/32

20

40

60

80

100

120

140

24002500

26002700

28002900

30003100

32003300

34003500

36003700

38003900

40004100

4200

Depth (m)

Tem

pera

ture

(deg

C)

Drims


Shoe Cut at 4245m

Loss zone

Run 1 - PSP plug in the string, T log after ~ 6hrs Run 2 – Sever the DP and pump ~400bbls 1.25sg “dynamic kill: followed by 90 bbls barite plug Run 3 - T log after ~ 8hrs Run 4 - After Cement plug

/32

20

40

60

80

100

120

140

24002500

26002700

28002900

30003100

32003300

34003500

36003700

38003900

40004100

4200

Depth (m)

Tem

pera

ture

(deg

C)

Drims

Run 1 - PSP plug in the string, T log after ~ 6hrs Run 2 - Sever the DP and pump ~400bbls 1.25sg “dynamic kill: followed by 90 bbls barite plug Run 3 - T log after ~ 8hrs Run 4 - After Cement plug

Shoe Cut at 4245m

Loss zone


/32

Plan of attack



• Set PSP plug to stop losses.


• Sever the DP and set cement plug to isolate the shoe.

• Sever DP at the shoe to release string.



/32 4606m

9 5/8” 2829m

4565m

4421m

6 ¾

” B

HA

5”

DP

5.87

5”

DP

5”

HW DP

Barite

Cement

E-line tagged obstruction 2631m

Uncertain shoe isolations

4606m

1279.2m BOP Shut in on Annular

Choke Line No Circ

Boo

st L

ine

OK

Riser

E line BOP

2 x FOSV

Kill Line No Circ

Status Schematic

Must regain access Attempted to mill cement Inside the DP using CT

trapped gas

/32

Plan of attack







• Mill cement inside DP and sever DP below shoe depth.



Coiled Tubing abrasive cutter

Risk of casing damage with E-line severance tools + Surface restriction at FOSV

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CT abrasive cutter

100 mesh sand

Slurry filter before the C.T realer Sand suspension test up to 90min

Sand concentration ~ 120 kg/m3 max

New Technology within Woodside.

Main Risks: 1. Eroded coil / surface equipment. 2. Plugged coil / surface equipment.

You want to do what ??!

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Coiled Tubing Abrasive cutter

• BHA

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Operations:

• Position cutting head at desired depth.

• Flush annulus 2 x annulus volume.

• Pumped pre determined slurry volume and successfully cut the DP.

• Flush annulus 2 x annulus volume and POOH.

Encountered issues.

• 2 X Cement unit failed during the pumping operations.

Coiled Tubing Abrasive cutter

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Plan of attack








• Cut DP above the shoe using CT abrasive cutter and cement the shoe.

• Remove Trapped gas below BOP


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Removing trapped gas below BOP

Operations:

• RIH CT Memory CCL.

• RIH CT abrasive perforate and punch hole.

• Bleed off gas below BOP.

• Strip DP and bleed off remanning gas below annular.

2 x 3/8” holes

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Choke and Kill line Coiled Tubing rig up

Return line

• Nipple down slip joint.

• Pulled out first riser joint and land on riser spider.

• RIH C.T jetting BHA ONLY and cleared up C&K.

Rotary Table

Riser Joint

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Plan of attack








• Cut DP above the shoe using CT abrasive cutter and cement the shoe.

• Remove Trapped gas below BOP

• Memory CCL.

• Run CT abrasive perforator and circulate the gas out.


/32

Themes

1. Contingency planning.

• Think a head to cater for escalation.

2. Problem solving.

• Require open minded and experienced team to adopt unconventional solutions.

/32

My personal take on this effort…

It’s not rocket science, but...

• Time frame very very short due to well control nature, but.

• My first well control experience.

• Variety of technical hurdles.

• Achieved the unachievable with no HSE incidents.

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Questions

recovery from hydrate plug during well control incident .... novel coil tubing.pdf · recovery from...

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