offshore platform slot recovery process

Asset Life Extension Process Platform Slot Recovery

GULF OF SUEZ PETROLEUM Co. GUPCO

D R I L L I N G E N G I N E E R

KAMEL ELSAYED

Slot recovery on J58-82 Site preparation for SB293-4 ERD WELL

ST BAHARI-1 TEAM

As operators cope with

maturing fields and

challenging market

conditions, it has become

increasingly important to

manage and extend the life

of assets

CONTENTS

STAGE I : SECURING THE STRING FOR CUTTING

STAGE II : MULTI STRING CUTTER

STAGE III : PULL THE CUT-OFF STRING

STAGE IV : CUTTING STRING INTO PIECES

STAGE V : P/U DCS

Before start cutting the multi-string conductor,

we had to apply tension on the string so it

would come out easily when cutting is finished.

Applying tension would also make cutting faster.

We did that using CTU, C-plate and a spider

elevator

1 1

• A conductor tensioner unit is installed on an offshore jackup rig to apply upward tension on the conductor.

• A Conductor Tensioning System consists of an elevated tensioning ring pinned to and supported by hydraulic tensioning cylinders, each of which are interconnected to a compensated hydraulic circuit employing bladder type accumulators.

• When the cylinders are hydraulically extended to their mid-stroke, the tensioning ring exerts a balanced upward pressure against a collar fitted around the conductor, thereby imposing vertical tension on the conductor string.

FIRST … WHAT IS A CTU ?!

CONDUCTOR TENSIONER UNIT

TYPICAL SPECIFICATION Tensioning capacity: 400 TON Max. conductor diameter: 36” (Adaptors available for smaller conductor diameters) Hydraulic cylinders: 8-Off (4-Off per half) Cylinder stroke: 610mm Accumulators: Up to 11-Off bladder type Nitrogen filled Mode of travel: Slot and claw type Skidding mechanism for travel across CTP structure

LARGE SKID-MOUNTED SPLIT CTU

CTU, inside

Cantilever

Conductor Tensioning Unit

WHAT IS A CTU ?!

STAGE #1: SECURING THE STRING FOR CUTTING

Removed the THS, then install 13-3/8” pulling tool onto the Braden head

CTU

C-Plate

Spider

Elevator

13-3/8” CSG

Pulling tool

STAGE #1: SECURING THE STRING FOR CUTTING

The C-plate supports the Spider elevator, which clamps on the pulling tool. Then the CTU pistons can be extended to apply the desired amount of pulling force.

CTU Hydraulic

Pistons

Now that we have the enough tension on the

string to be cut, cutting operation can

commence.

2 2

STAGE #2: MULTI STRING CUTTER


MSC knives protruding from the 24” conductor due to eccentricity of casing strings

MSC got stuck while trying to cut the rest of the 24” Conductor (due to eccentricity)

After many trials of rotating and applying overpull, we were successful to pull the

MSC out with all knives recovered

Multi-String Cutter Note


Damaged knives after POH … and knives were stuck in place and back-loaded as it is .

We think that knives got bent laterally due to high torque applied to them … not because of the over pull or slack

As a result we couldn’t get the knives back in place and that why we had to put

extra pull to retract them.

The sides of the knives had peeled off while trying to retract knives into place.

Multi-String Cutter Note


The sides of the knives had peeled off while trying to retract knives into place.


We ran in hole again with new set of knives and could successfully cut thru.

CSG Stump Eccentricity of CSG strings is very clear

Cut-off string

Now we can recover the cut-off string to the

surface, but first we have to secure it.

3

STAGE #3: Pull the cut-off string

1- On the Production deck, Below the braden head, Cut window thru the 3 CSG strings and install a pin as a securing pin (not to allow any string to slip off) and as a lifting pin as well.

STAGE #3: PULL THE CUT-OFF STRING

2- Remove the Spider Elevator and C-plate 3- Pull the string till the Braden head is above the rig floor

4

Now we have to cut the string into smaller

pieces that can be handled and transported

We’re going do that using:

1- BORAIS Dual pin drill

&

2- BORAIS Guillotine pipe saw

• Dual Pin Drill with hydraulically-powered twin opposed drills are used to prepare cut sections of casing for securing and rigging.

• Dual Pin Drill incorporates two opposed drills on a mounting frame for drilling precisely aligned holes through which bolts or pins can be inserted to secure multiple-layered casings. Holes up to 4” can be drilled.

DUAL PIN DRILL Quick Note

BORAIS DUAL HOLE DRILLING MACHINE

BORAIS DUAL HOLE DRILLING MACHINE IN ACTION

STAGE #4: CUTTING STRING INTO PIECES

Carbide inserts

Cut-off pieces due to hole drilling

24” 13-3/8” 9-5/8”

• Designed to cold cut 16” to 32” pipe of all materials, as well as solids , and multi-stranded casing strings, can work in sub-sea conditions.

• It has Auto-clamp & Auto-feed features.

• A 16” diameter 3/4” wall steel pipe is cut in only 24 minutes. • A 32” diameter multi-stranded casing string is cut in about 48 minutes.

GUILLOTINE PIPE SAW Quick Note

BORAIS GUILLOTINE PIPE SAW


Cut-off the first joint by BORAIS Guillotine pipe saw, and L/D on cantilever


Securing Pins … is inserted into the drilled hole to prevent any of the casing string of slipping off. It’s also secured by welding and wedges preparing for backload

5

P/U DCS parts and weld it on rig floor

BLIND BTM WITH SPIKES

DCS PART #1

DCS PART #2

XLF BOX THREAD

2 x 30” XLF CONDUCTOR JOINTS

XO 30” XLF PIN x 4-1/2” IF BOX

XO 4-1/2” IF PIN x 5-7/8” VX-57 BOX

5-7/8” VX-57 DRILL PIPES

ALL WELDED

STAGE #5: P/U DCS

DCS ASSEMBLY

STAGE #5: STAGE #5: P/U DCS

DCS part #1

STAGE #5: P/U DCS

Blind end with spikes that will grip into sea bed and prevent DCS movement with sea current

6

WAIT ON WEATHER TO RUN WITH ROV TO

ENSURE AREA AROUND OLD CASING STUMP

IS CLEAR FROM ANY DEBRIS

WAIT ON WEATHER TO RUN WITH DCS

Production deck

Cellar deck

After Running with the DCS, orienting it in the new well direction, it

should be secured to the platform by clamps to the

cellar deck and the production deck, then cold-cut the DCS just above the production

deck

Later after the rig leaves the platform, other

clamps can be installed on the subsea bracings.

Forward Plan

KAMEL ELSAYED DRILLING ENGINEER

BAHARI-1 RIG TEAM

[email protected]

0122 910 2341

THANKS FOR YOUR TIME

offshore platform slot recovery process

Engineering