--> ABSTRACT: Determination of Reservoir Compartment Size Distributions for Maximizing the Recovery of Natural Gas in Fluvial-Dominated Reservoirs, by Raymond A. Levey, Mark A. Sippel; #91020 (1995).

Datapages, Inc.Print this page

Determination of Reservoir Compartment Size Distributions for Maximizing the Recovery of Natural Gas in Fluvial-Dominated Reservoirs

Raymond A. Levey, Mark A. Sippel

A major goal of the reservoir characterization research conducted by the Bureau of Economic Geology on behalf of the U.S. Department of Energy and the Gas Research Institute is to develop strategies for maximizing economic recovery of natural gas in reservoirs having conventional porosity and permeability. Statistical predictions of natural gas recovery were developed for a spectrum of fluvial reservoirs characterized as bed-load, mixed-load, and suspended-load facies architecture. Three classes characterized by large, medium, or small reservoir compartment sizes (gas-filled pore volume) were delineated from middle Frio reservoirs over a 2,000-ft interval in Stratton-Agua Dulce field, South Texas, that has produced more than 2 Tcf of natural gas. Producing rate and static pressure data were used from 256 completions to determine the three fundamental reservoir parameters: primary drained pore volume, supporting pore volume, and barrier transmissibility. The primary pore volume and transmissibility were found to be closely approximated by a log-normal distribution. Recovery factors were evaluated for different well spacing and completion timing scenarios. Forward stochastic modeling of gas recovery from the three compartment size classes indicates that well spacing of 340, 200, and 60 acres (or less) provides maximum gas contact efficiency. For example, in the small compartment size class, incremental recovery potential of 24 percent is predicted by decreasing completion spacing from 320 to 160 acres. The correlations developed should be transferable to ot er fields with similar fluvial facies architecture and other linear reservoirs.

AAPG Search and Discovery Article #91020©1995 AAPG Annual Convention, Houston, Texas, May 5-8, 1995