Abstract
Field production performance data and multiple pressure transient tests over a period of time for oil and gas wells in geopressured reservoirs have been found to often exhibit marked changes in reservoir effective permeability over the producing life of the wells. Similarly, the use of quantitative fractured well diagnostics to evaluate the production performance of hydraulically fractured wells have clearly shown that effective fracture half-length and conductivity can be dramatically reduced over the producing life of the wells.
This paper reports the results of the research, development, and application of production performance analysis models to directly measure the changes in the reservoir effective permeability and fracture effective conductivity of hydraulically fractured wells completed in reservoirs that are subject to stress-dependent variation of the intrinsic formation and fracture properties. The interpretation model development is documented in the Appendices of this paper. Field examples are presented which demonstrate the application of the interpretation models to both unfractured and hydraulically fractured well production performance analyses in which stress-dependence of the reservoir and fracture properties are clearly exhibited.
