The "A" West field is located on the Eastern Flank of the South Oman Salt Basin. The field is at Haima level and is a classic high relief ‘turtle-back’ fault-bounded, anticline approximately 4kmsx2kms oriented North-South. It is a dome shaped structure with large oil columns of 200+m. The thickness of the oil column and the reservoir quality make the reservoir a good candidate for steam flooding ... [Show full abstract] with high thermal efficiencies. The field received FID for thermal development based on a vertical well 10-acre 7-spot pattern in 2009.
The "A" West steam-flood pilot started in 2008 as an inverted 10 acre-7 spot pattern comprising a vertical steam injector surrounded by six vertical oil producers located 125 m from the injector and three observation wells. Five years after the start of injection in the "1P" pilot area, a temporary increase in hot oil production has been observed in one producer of the "1P" pattern. The temperature and net oil increase started in February 2010, some 14 months of injection and continued till January 2011, when the injector well was abandoned and replaced with new injector as part of the facilities "urban development" plan. The switch of the wells was accompanied with the change in the perforation interval to the lower half of the oil column in an attempt to improve the steam conformance within the pattern.
The in-depth analysis of existing and newly acquired well and production data with the integration of the formation pressure tests, seismic, pressure and temperature data with detailed simulation models provided new insights that together helped in explaining the performance of the thermal EOR process. This has also helped in optimizing the pattern size and improve steam conformance to maximize the sweep efficiency.