ACCIONES DE ESTABILIZACIÓN DE SUELOS Sembrados

13.4.1. Equipment Preparation and Siting

1) Ensure that the equipment has been visually checked for defects prior to starting rig- up.

2) If time allows, a permit should be obtained and the equipment run and tested, prior to the commencement of the operation, to check equipment function and confirm the operation of the shut down systems on the power pack.

3) The Well Operations Supervisor should ensure that:

• The work area is suitably guarded (e.g. safety barriers, safety signs, etc.).

• Any scaffolding is secure, safe and properly certified.

• The crane operator and roustabouts are aware of the equipment weights and hazards (e.g. liquid nitrogen or acid, etc.).

• All lifts should have tag lines attached. 13.4.2. Coiled Tubing Rig-Up

Note: The C/T unit will be function tested on the deck prior to it being made up in the well.

Note: It is Company policy to run a remote hydraulic control shear seal BOP at the bottom of the riser immediately above the tree.

Refer to figure 13.a General rig up arrangement.

1) Confirm that the tree has been de-pressurised and the controls have been isolated from the main control system.

2) Take control of the well from Production Department.

3) Remove the swab cap and inspect the thread and seal areas.

4) Run the riser (with the shear seal BOP at the bottom) onto the tree and pressure test with water to 500 psi above the maximum anticipated surface pressure or to the maximum test pressure of 5,000 psi, whichever is lower. Do not exceed the maximum allowable tree rating.

5) Position the tubing reel and power pack so that the coiled tubing has an unrestricted path to the injector head.

6) Move the BOP assembly onto the rig floor or skid deck, make up to riser and pressure test. Function test the BOP with both panels, fill up the riser and BOP with glycol/water, close the blind rams and pressure test the riser, return lines and blind rams to 500psi above the maximum anticipated surface pressure, or to the maximum test pressure of 5,000psi, whichever is lower.

7) Clamp the coiled tubing at the reel using a certified clamp but not molegrips or other similar tools.

8) The injector head may be rigged up and the tubing stabbed through the injector head on the catwalk or drill floor depending on space available.

1) When picking up the injector head, use tugger lines to keep the assembly vertical. Tugger lines must not be attached to the injector body, as this will interfere with the weight indicator readings.

2) Fill the reel with water. The reel should be flushed with water and pigged with a no-go prior to running packers and other sensitive tools to gauge reel volume, ensure that there are no restrictions to the ID of the coil and to purge any debris form the tubing. Make-up and fit the end connector and test sub. Test reel to full test pressure and perform pull test before stabbing on to BOP.

3) Attach the C/T BHA, and stab the injector onto the BOP.

4) The assembly will be pressure tested with the BHA across the BOP. 13.4.3. Pressure Testing

Pressure testing of the coiled tubing assembly, which includes the BOPs, tubing, treating lines and the pump, should be carried out in a logical sequence to eliminate all possible leaks.

1) The Blind Rams and Riser will have already been tested while rigging up the BOPs, therefore it is certain the BOP to riser seal, riser to tree seal, swab valve, BOP kill wing valve and blind rams have pressure integrity.

2) If using an in-line tubing connector, the Stripper/Packer and Toolstring will be tested with the tools across the BOP and the straight bar in the energised stripper. With the whole system full of water, pressure is applied from the pump in stages of 500psi up to a maximum of 5,000psi. The pump and treating lines up to the reel will have been tested already. Do not exceed the maximum allowable tree rating.

3) If using an out-line tubing connector, the Stripper/Packer and Toolstring will be tested with the tools below the BOP. With the whole system full of water, pressure is applied through the tubing in stages of 500psi up to a maximum of 5,000psi, to prevent collapse of the tubing.

4) The Pipe Rams are now tested by closing the pipe rams and bleeding the pressure down to zero via the circulating port on the BOP. Once the test is complete, close the circulating port and equalise the pressure across the pipe rams.

5) The Check Valves in the toolstring are now checked using the pressure already in the system. With the straight bar still across the still energised stripper, bleed down the pressure at the reel. The check valves should seal, and pressure will remain in the riser and BOPs while the reel pressure is zero. When bleeding down reel pressure, ensure external pressure does not exceed the collapse pressure rating of the reel. 6) Alternatively, bleed down the whole system at the BOPs and with the reel valve open,

using the cement or pressure test pump, pressure test check valves via a pump-in tee below the BOPs while stripper is energised.

Figure 13.A - General C/T Rig Up Arrangement C on tro l C ab C oi le d Tu bi ng R ee l Po w er S ki d G oo se N ec k In je ct or H ea d H yd ra ul ic H os e S tri pp er /S tu ffi ng Bo x Q ua d BO P' s Lu br ic at or /R is er W el lh ea d C om bi na tio n BO P' s W el lh ea d

13.4.4. Treating Lines

• On all C/T operations, treating lines should be rigged-up using certified Fig.1502 integral lines.

• Any bent lines or damaged unions will be marked, registered as unfit for use and returned to base.

• Ensure that the lines are tied with safety cables and attached at regular intervals to secure fixing points.

• Ensure that check valves are used on wellheads, reels and each pump.

• Ensure that a certified relief valve is installed in the surface line circuitry. The relief valve setting is to be confirmed between the Company and Contractor Representative prior to equipment load out.

• All valves should be tested from the well side including the last valve on the reel. 13.4.5. Injector Frame

An injector frame is used to steady and position an injector when operated rigless. It may also be used when operating through the rig although this is not recommended as it serves no purpose and requires additional rig-up time.

On floaters a special lifting frame or extra long bails should be attached to the block to the surface tree to maintain tension through the compensation system. The injector is then installed inside the lift frame or bails. This enhances the safety of personnel and enables easy rig up of the injector head on a heaving rig.

The injector frame is not designed to withstand the weight of the injector and the weight of the coiled tubing in the hole. This combined weight, which can be in the region of 20 tonnes, is carried by the wellhead. The purpose of the frame is only to ensure lateral stability.

Most frames have hydraulic height adjustment and should include hydraulic compensation systems to allow for any vertical movement of the wellhead in relation to the deck.

The frame should be pegged to the injector and tied back at the four top corners using certified chains and come-alongs, to secure fastening points on the deck.

The injector should remain connected to the crane or overhead gantry crane during the operation to add stability to the structure and to facilitate rapid removal of the injector during rig down. Due to possible contraction of the riser due to well cooling, no tension should be applied to crane sling during operations.

13.4.6. Rigging Down To rig down:

1) Pull out of the hole until the tubing end connector tags the stripper. Use no more than 4,000lbs overpull.

2) Close off the well isolation valve.

3) Bleed off pressure in the coiled tubing and surface lines through the closed line drain in case of any hydrocarbon discharge.

4) Rig down the coiled tubing and associated equipment. 5) Ensure all equipment is stowed safely for transport.