Principales logros alcanzados en los programas, proyectos, estrategias y aspectos relevantes y/o prioritarios

BP EXPLORATION (XEU) WELL TESTING PROCEDURES MANUAL

SECTION 3020

SUBJECT HYDRAULIC FIRING OF TCPS

REVISION 0

DATE 01/10/92

HYDRAULIC FIRING OF TCPS

1. SAFETY

1.1 This operation effectively marks the transition from the preparatory phase to the operational phase of well testing. Work permits must be resigned or new permits issued prior to starting the operational phase.

1.2 Confirm that the flaring telex has been sent.

1.3 Ensure that there are no boats below the burners, and that the standby boat has been alerted.

1.4 Make a tannoy announcement and clear the rig floor of all non essential personnel prior to pressuring up to initiate firing. Rope off the high pressure areas.

1.5 Detonation of the charges (especially on shallow wells) can cause the string to jump.

While waiting for the charges to fire, keep non essential personnel clear of the rig floor.

1.6 If the guns fail to fire after the programmed delay time, wait a further 30 minutes before allowing any personnel to mechanically operate the flowhead valves.

1.7 Perforating can be carried out during hours of darkness.

BP EXPLORATION (XEU) WELL TESTING PROCEDURES MANUAL

SECTION 3020

SUBJECT HYDRAULIC FIRING OF TCPS

REVISION 0

DATE 01/10/92

2. PREPARATION

2.1 Calculate the WHP required to initiate firing of the TCP guns.

2.2 Set packer, and set any reference tools or any tools that have been shear pinned, eg PORT/ARTS/LPR-N

2.3 Ensure that the Data acquisition system is working and recording on all channels. Set up the WHP to record at 30 second intervals with a 10psi delta P trigger.

2.4 Walk the surface lines checking that from the choke manifold, the well is lined up direct to the burners, by-passing all vessels.

3.2 Close the pipe rams around the SSTT slick joint and apply 2000 psi annulus pressure to open the Tester valve. Check the Data acquisition system for a small kick in well head pressure indicating that the tester valve opened.

3.3 Using the cement pump increase tubing wellhead pressure to psi. Hold for 1 minute.

Bleed off pressure to psi.

3.4 Observe surface pressure for indication of guns firing. (Sudden drop in WHP followed by a steady increase). Expected time delay is _____ minutes

3.5 Allow WHP to increase with the well shut in at surface for 5 minutes.

3.6 Bleed off annulus pressure to close the tester valve.

3.7 Leave the well shut in downhole for a 55 minute PBU.

3.8 If the guns failed to fire, refer to Guidance notes.

If, after the programmed delay period, there is no evidence of the guns firing, wait for a further 30 minutes, then repeat the firing process but pressure up to 1000 psi above the previous firing pressure.

When repressurising, plot the bbls pumped versus WHP as in a leak off test. This should identify if the guns fired but the reservoir was tight or if the guns failed to fire.

If again after the programmed delay period there is no evidence of the guns firing, wait for a further 30 minutes, then prepare to use the back up firing system, if

available/installed.

4.2 Mechanical Firing of TCP's

Bleed off annulus pressure to close the tester valve. Bleed off sufficient wellhead pressure to confirm that the tester valve has closed. Shut the lubricator valve and bleed off all pressure. Flush the flowhead and surface lines if necessary.

With the swab valve closed, open the 1/2" needle valve on the swab cap and bleed off any pressure. remove the swab cap.

Rig up the slick line BOPS, close the rams. Open the swab valve and pressure test the BOP's.

Rig up the lubricator, slickline tool string and detonating bar, pressure test the slick line lubricator to 300 psi for five minutes and psi for ten minutes.

With the tool in the tool catcher (if present), bleed off pressure to equalise above the lubricator valve. Open the lubricator valve.

- Inject slowly through the chemical injection line to determine the pressure below the lubricator valve.)

Close the kill valve.

RIH at maximum speed until 100m above the tester valve. Slowly RIH and tag the tester valve. Reference the slick line depth counter.

Pull the tool string back up into the tubing.

Apply annulus pressure to open the tester valve.

Apply/bleed off pressure to achieve psi underbalance.

Ensure that the WHP is at least 100 psi. This will ensure that the data gathering system can detect if the guns fire.

Ensure the data gathering system is sampling every 30 seconds with a 10 psi delta P trigger on the WHP.

Inform Driller and BP Rep prior to perforating.

RIH and tag ported glass disc sub.

Pick up 20m.

RIH allowing the toolstring to accelerate to its maximum velocity. Break through the glass disc sub and continue to RIH until the toolstring lands out and jars down on the firing head.

(Breaking through the glass disc and RIH to the firing head must be done in one

continuous movement so that the drop bar reaches the firing head before any debris from the disc sub)

Jar down until guns fire.

Allow WHP to stabilise and POOH slickline.

If guns do not fire, POOH slickline, and prepare to POOH gun string.

When perforating with TCP's on drill pipe the primary mode of initiating firing will be by applying pressure down the annulus or tubing. The back up initiating system is a drop bar run on wireline.

Ensure the electronic data gathering system is sampling tubing/annulus pressure at 30 sec intervals with a 50 psi delta P trigger.

Clear the rig floor of all non essential personnel prior to perforating.

Close the middle pipe rams and apply 500 psi annulus/tubing pressure. Check electronic data gathering system is working.

Increase annulus/tubing pressure to firing pressure of psi. Hold for 1 minute. Bleed off pressure to 100-200 psi.

Observe surface pressure for indication of guns firing. If there

is no evidence of the guns firing after the delay period, wait a further 30 minutes then repeat the process but pressure up to 3000 psi to activate the guns.

If again there is no indication of the guns firing after the delay period, wait a further 30 minutes then prepare to use the back up firing system.

After the guns have fired, note trip tank level and monitor well for losses.

Circulate in an LCM pill as necessary.

POOH and rig down guns.

All non-essential personnel must stay clear of the gun disassembly area, the rig floor and BOP deck while the guns are being rigged down.

All Hydraulically fired TCP systems can be fitted with a delay system to enable the firing pressure to be bled off and the well under balanced. Delay systems come in two main types:

- Slow burning fuses.

- Hydraulic metering/restrictor system.

Slow burning fuses are available in units with delay times of 5 or 7 minutes, depending on the supplier. To achieve a longer delay the units are stacked. The duration of the delay is independent of bottom hole temperature and pressure.

Hydraulic metering/restrictor systems are available with a wide range of delay times. The actual delay period will depend on the bottom hole pressure and temperature. If the bottom hole temperature was higher than prognosed or if a problem delayed bleeding off of the TCP firing pressure, then the delay period could be shortened by up to 25%.

In practice 10 - 15 minutes is the ideal delay period. This allows time to bleed off firing pressure without rushing and four or five minutes of spare time should any minor problems occur, eg Choke valve is pressure locked closed.

On shallow wells where the bleed off volume is small it can be practical to use a 7 minute time delay. However if any problems occur there is very little time to rectify the problem and overbalance perforating can result.

4.5 Steps 3.6 and 3.7 can be omitted if the well is being flowed straight to clean up without an initial shut in period.

4.6 If the failed firing head is wireline retrievable, then the failed head should be recovered, inspected and the cause of the misfire identified prior to any further attempts to perforate the well.

1.1 Prior to rigging up the pressure equipment hold a safety meeting on the rig floor to discuss the operation. The safety meeting should include, but not be limited to; the BP REP, OIM, Toolpusher, Driller, Logging Engineer, PE, rig crew and test crew. The following points should be noted at the safety meeting:

a All assembly/disassembly of the guns is to be carried out under the supervision of the Logging Engineer. and must be maintained until the guns are 70m below the sea bed. Only when an approved 'Radio Safe' perforating system is being used can radio silence procedures explosives store and remain so until the guns are 70m below the sea bed, or the detonator is returned to the explosives store, or the detonator is consumed in the perforating operation. All hand portable radio equipment must be recalled to the radio-room and only re-issued when perforating operations are complete.

ii Check that the stand-by boat and any other vessels in the vicinity of the rig have moved outside the 500m zone and remain there for the duration of the operation. All vessels within one kilometre must silence all MF/HF transmissions. Should it be necessary for any shipping to remain within 500m of the rig they must observe radio/radar silence.