Variation of Fracture Opening with Pressure -- Key to Well Productivity in NaturallyFractured Reservoirs

摘要

Naturally fractured reservoirs usually developed many scalesrnof fractures, for example, the super-high-permeability flow inrnbig fractures, mid-permeability flow in small fractures andrnvery-low-permeability flow in matrix rock. This results in thernsubsurface multi-scale flow during the reservoir development.rnThis multi-scale flow makes it tougher to analyze the wellrnproductivity than that of a conventional reservoir. In thisrnpaper, muti-rate well-testing data were used to calculate thernproduction capacity at different reservoir pressures in naturallyrnfractured reservoirs. The method is exemplified with two wellsrnin a case reservoir. The calculation results are very similar tornfield production data. We conclude that oil production rate inrnthese kind of reservoirs is not only impacted by both twophasernflow and non-Darcy flow as in conventional reservoirs,rnbut also impacted by the variations of fracture opening. Thisrnconclusion can be used to better define the optimal rate for thernreservoir under different reservoir pressures, thus furtherrnimprove our forecast accuracy and overall field developmentrnresults.