With the continuous increase in global energy demands, it has become imperative to get the most out of the existing reserves in developed fields. While focusing on maximizing productivity, the conventional methods of well completions are not always optimal. Cemented Liner Completions in multi-layered reservoirs can at times be in-efficient and thereby create issues of zonal isolation and well integrity, besides causing irreversible damage to reservoir sections. To overcome these obstacles, and to provide an added advantage of selective stimulation in multiple zones, industry is gradually moving towards open-hole multi Stage Frac Completions.
This paper presents an operational overview of first ever deployment of an open-hole completion in a mature gas condensate field located in Potohar region in Pakistan. It had been a norm in this field to hydraulically fracture the two producing zones after cementing the liner. However, often the fold of increase was very marginal despite establishing the hydraulic fracturing design patterns for this field with confidence. In addition, these stimulating operations were frequently compromised because of well and completion design constraints.
Execution of open hole completion resulted in gains in the operational efficiency, improved well productivity and had cost benefits which are analyzed against offset wells completed as cased-hole. One interesting observation made is the comparison of un-stimulated base case for the well under discussion against various offset wells located in the field that were hydraulically fractured and how it outshines them with respect to the net production gains. This can be attributed to the characteristic of open-hole completions that provides maximum reservoir contact with minimal formation damage. Based on this experience, it is recommended on integrating and experimenting with relatively new, yet industry established, ideas into field development plans for mature fields with respect to completion design. This can have a lasting impact in extending the plateau production region of the field.