Case Study of Gas Migration in the Wasatch and Mesaverde Formations of the Piceance Basin, Colorado

Abstract

Summary The U.S. DOE Morgantown Energy Technology Center (METC) conducted a reservoir simulation study and an engineering analysis on gas migration for two tight lenticular sandstone units, the Wasatch formation and the Mesaverde group, in Garfield County, CO. The study quantified potential gas loss through migration from the Naval Oil Shale Reserve (NOSR) No. 3 (Fig. 1) to nearby producing wells located in the Rulison field and forecasted production for proposed NOSR No. 3 offset wells located at previously selected sites, offsetting commercial wells outside the reserve. After the reservoirs were characterized, production was forecasted by use of a reservoir simulator to history match actual production. A dual-porosity reservoir simulator, developed specifically for naturally fractured gas-producing reservoirs, and reservoir engineering calculations were used in the study. The study followed two extensive DOE field testing programs, a nearby multiwell experiment (MWX), and a special Mesaverde test well (1XM9) drilled in NOSR No. 3 (see Figs. 1 and 2). These DOE field tests provided geologic information and values for reservoir parameters that control production from this unconventional gas resource. In addition to the results from the two field experiments, the study used a detailed geologic analysis and production data from nearby industry wells to characterize the producing formations.