The careful planning and successful execution of a multi-stage fracture stimulation completion in one of the first horizontal wells drilled in the Amin Formation instigated a step change in initial production rate and long term deliverability from this tight gas sandstone reservoir in North Central Oman.
The field was discovered in 1993 but remained undeveloped due to low deliverability from single-stage hydraulic fracturing treatments. Previous vertical Amin completions, though intriguing, failed to deliver satisfactory production rates. Hydraulic fracturing stimulation technology is critical to achieving commercial rates in tight gas formations. The operator and service company worked as a team, modeling the fracturing program after North American practices, prescribing a novel approach for the Sultanate of Oman.
The vertical completion profile was changed to horizontal multi-stage fracturing, to increase reservoir contact. North American unconventional reservoir stimulations were investigated by pumping cross-linked gel, slick water, and hybrid fracs across six stages along the horizontal section. Several reservoir access options were tested to evaluate fracture initiation points including sliding sleeve, jet perforating, and abrasive jetting. Various well intervention strategies and zonal isolation techniques were also deployed. Extensive cased-hole logging was employed to evaluate the effectiveness of each stage.
A full range of integrated surveillance, including open-hole characterization, production logs, and BHP monitoring was used to evaluate formation behavior, fracturing effectiveness, and intervention activities, achieving optimum operational and production results for potential application to full field development.
Adopting best practices from other regions and integrating comprehensive surveillance data is helping to unlock the potential of the Amin tight gas reservoir. The KZN-F well is used as a case study throughout this paper.