Simple and Reliable Innovative Fluid Dynamic Technology Maximizes Oil Recovery in Upper Burgan Reservoir

摘要

Production in the Upper Burgan reservoir began in the Raudhatain and Sabriyah fields in 1959 and 1970, respectively. However, significant quantities of original oil remain in the reservoir; although the Upper Burgan fields have both been in production for more than 56 years, the offtake to date is a relatively small percentage of the potential ultimate recovery. The sandstone of the Upper Burgan is typically fine grained. Porosities average 25% and can reach 30% in the best quality sands. Horizontal permeability values of 200 to 700 md are common, with variation in vertical permeability caused by changes in the texture and structure of the reservoir. In 1995, the operator initiated a strategy to significantly increase production from these North Kuwait fields by integrating a multidisciplinary team from within the operating company. Waterflooding was part of the Upper Burgan development plan, during which the heterogeneous reservoir was expected to encounter early water breakthrough compared to other North Kuwait reservoirs. After 20 years of waterflooding in the Upper Burgan, the water cut reached 50%, and water management became crucial with reduced hydrocarbon recovery from the field. Autonomous inflow control device (AICD) technology with screens was installed in a pilot well in the Upper Burgan reservoir to help reduce the water production and increase the oil recovery from the well. AICD technology uses fluid dynamics technology to differentiate the fluids flowing through the device. When water breaks through, the AICD creates a pressure drop to restrict production flow at that device, favoring the production of the healthy oil-statured zone, thus increasing expected ultimate recovery from the well. The AICD has no moving parts, electronics, or connections to the surface and employs a unique geometry that alters the flow path within the tool upon water and/or gas breakthrough. This technology has helped improve recovery by reducing water cut from the high water-saturation zones, thereby increasing the overall oil recovery from the well. Forecasted well performance with AICD technology is in line with actual production and water cut.