Andrew Padilla, Chevron Production Co. & Jay Miller, TAM International Inc.
Applying horizontal well technology to improve oil recovery in reservoirs undergoing active water flooding continues to evolve with improving success. Development of remaining unswept oil reserves with horizontal wells as a method to improve conformance is a significant challenge. Evaluating and optimizing well performance to achieve economic results in a waterflood setting is a critical step in maximizing the success of a horizontal well project. Horizontal laterals expose large amounts of productive reservoir rock, benefiting certain reservoir applications while adding a major risk component to well designs planned for heterogeneous, water flooded carbonate reservoirs. Long laterals increase potential of exposing undesirable geologic conditions such as waterfilled fracture networks, zones of high water saturation and extreme permeability of thief zone intervals. A significant negative impact on well performance from high water production rates can result in lower oil rates and excessive lifting costs. This paper summarizes methods and experiences in mechanically evaluating and diagnosing fluid entry in newly drilled horizontal wells, efforts and results to control water entry and optimize well performance. Also discussed are field test results of a new tool design combining re-settable, inflatable packers and a hydraulic jet pump. Early field test results suggest this method will be a promising advance toward efficient diagnosis of fluid entry in both vertical and horizontal wells.