The already complex job of diagnosing production problems and flow profiling in a multiphase environment is further complicated by the complex flow regimes encountered in horizontal, highly deviated, and slim wells. Accurate holdup measurements are needed to clearly identify the first point of hydrocarbon or water entry, and independent oil, water and gas flow rates versus depth are needed to obtain overall downhole flow rates and to identify production from each perforated interval. Qualitative fluid identification is also needed to help determine the type of fluids contributed by each zone. Finally, imaging of the well bore is needed to detect cross flow, circulating flow, and phase segregation.
The latest generation of production logging tools has traditional measurements such as pressure, temperature, density and spinner redesigned to deliver superior accuracy and resolution. New sensors such as local electrical probes for holdup have been collocated with the spinner and an integrated X-Y caliper to provide accurate answers in complex flow regimes. Introduction of this advanced production logging technology in the fields of the Gulf of Suez has represented a virtual breakthrough in the use of production logging in that company. This has enabled the diagnosis and treatment of problems previously undetectable and hence unsolvable due to excessive well deviation, high water cut, or mixing of water injected and formation waters. Correct diagnosis has resulted in proper work over planning and application and, in turn, to improved reservoir management practices.
This paper describes this new technology and presents case histories in which operators in the Gulf of Suez have successfully employed revolutionary production logging improvements to provide timely cost-effective diagnosis for some of the most challenging well production problems.