Case Study: Remote Offshore Well Recompleted from a Small Unmanned Platform

The eFire-Slickline firing head system anchored a reperforation string that delivered success and savings

Challenge: Reperforate the Malong-A0 4L well from a small, remote, unmanned platform equipped with only a three-ton, manually operated hydraulic crane.

Solution: Use the eFire-Slickline electronic firing head system for slickline deployment with the IRIS intelligent remote implementation system, HSD high shot density gun system, and PowerJet deep penetrating shaped charges for an integrated solution.

Result: Performed a successful slickline operation that minimized time, equipment, and manpower requirements.

PCSB wanted to reperforate a well from a remote platform with a very small crane

Petronas Carigali Sendirian Berhad (PCSB) wanted to reperforate the Malong-A0 4L well to restore Malong-Anding-Sotong field production to its optimum level.

The well was produced from a small, remote, unmanned platform equipped with only a three-ton, manually operated hydraulic crane. This imposed limitations on the weight and size of equipment that could be used for the operation and precluded the use of conventional wireline or coiled-tubing perforating technologies.

Also, the size of the gun string was limited by the completion string restriction of 2.25 in, and PCSB requested that the job be expedited so that the shut-in period would not extend beyond 2 days.

Schlumberger proposed a slickline-deployed system built around eFire system

PCSB and Schlumberger collaborated to customize a perforating solution for the Malong-A0 4L well that would enable all objectives to be met.

To accommodate the significant restrictions and limitations, Schlumberger proposed using an eFire-Slickline electronic firing head system with an IRIS remote implementation system, a 2-in HSD gun system, and PowerJet charges. Deploying this string with a standard slickline unit would eliminate the need for heavier wireline or coiled-tubing equipment, enabling safer working load requirements of the platform crane to be observed. Maximum gun swell after perforation would still allow retrieval of the 2-in guns.

The successful recompletion minimized time, equipment, and manpower requirements

The eFire firing head was programmed and deployed. Jerks on the slickline initiated the system sequence of arming, firing, and disarming in a specific time window, ensuring an effective explosive operation without incident.

Once the guns had fired, an increase in downhole pressure was observed as expected and confirmed the penetrations had reached the formation. When the string was retrieved to surface, all the explosive charges were found to have fired. Pressure data downloaded from the eFire tool confirmed that the Malong-A0 4L well had been successfully reperforated. The operation was completed within the time limit given by PCSB, and all objectives were accomplished in four very efficient runs, helping improve field productivity.

Operational safety was enhanced by the exclusion of primary explosives and the fact that the eFire activation process includes the capability to abort the firing sequence at will. Being able to use eFire technology on a standard slickline unit prevented platform and crane limitations from compromising the operation and eliminated the need for conventional perforation methods that would have required more time, equipment, and manpower.

Download: Remote Offshore Well Recompleted from a Small Unmanned Platform (0.72 MB PDF)

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