Repair of Gravel Pack Assembly in Horizontal Well in Highly Unconsolidated Sand Stone Reservoir

Goyal, Mayank (Oil and Natural Gas Corporation Ltd) | Singh, Pramod Kumar (Oil and Natural Gas Corporation Ltd) | Parmar, Kishan J. (Oil and Natural Gas Corporation Ltd) | Pareek, Ramesh C. (Oil and Natural Gas Corporation Ltd) | Prasanna, Guru V. (Oil and Natural Gas Corporation Ltd) | Dey, Sumanta Kumar (Oil and Natural Gas Corporation Ltd)



Repairing or recompletion of gravel pack (GP) assembly in horizontal wells is a real challenge. Complete or partial retrieval of GP assembly and re-GP or re-makeup of part of its subsurface hardware is critical, time consuming, complicated and yet uncertain. Such jobs being complex in nature, the attempts often lead to abandonment of the well causing huge capital loss. This paper intends to highlight the success story of repairing GP assembly in a horizontal well in short span of time and reviving the well on production.

In-situ combustion (ISC) process, a thermal Enhanced Oil Recovery (EOR), is under commercial application in one of the heavy oil field of ONGC. To capture the combustion displaced oil and to improve the efficiency of ISC process, an unconventional horizontal oil producer (BL#XY) well drilled against 4° dipping reservoir with maximum angle of 94.8° showed exceptionally encouraging results. The well drilled with 300 m horizontal drain hole horizontal section of the well was completed with Gravel Pack (GP) using conventional lead seal assembly (LSA) as a part of over the top assembly stabbed at ~82.8° incli-nation to arrest sand incursion. The well was put on artificial lift mode (Sucker Rod Pump) for maximum designed liquid withdrawal of ~315 bbls/day. Under the effect of ISC, the well produced liquid at the rate of 1500 bbls/day with 30% water cut. After sustained production of few months, the well ceased to flow due to sand incursion. In depth analysis of flow behavior of the well & response of rig less interventions indicated that improper sealing of LSA at high angle could be the potential escape route of sand/gravel under the influence of high production rate leading to GP failure. This paper illustrates the details of initial completion, attempts made to revive the well, problems encountered during fishing GP Assembly, mid-course corrections adopted to recomplete the well with customized down hole assembly and new over-the top assembly. Meticulous planning and perfection in execution of work over operations resulted in successful repairing of GP and revival of the well.

A cross-over with 8 O-rings, an innovative and fit to the purpose tool designed & fabricated in-house along with the modified Bottom Hole Assembly (BHA) was latched co-centrically with the intact part of the assembly and then GP packer was set hydraulically. The integrity of the repaired GP assembly was tested and found OK. The well was put back on production with SRP mode of lift. Presently, the well is producing 500 bbl/d of liquid. The in-house engineering has revived an expensive horizontal well and saved significant expenditure.

This paper would be of interest to engineers and technicians associated with completion or gravel packing jobs and will provide them insights of such completions in highly deviated wells. It also provides an understanding of the importance of GP Packer setting depth and repairing of GP assembly in case of failure.