This study is a comparative evaluation of predicted gas production from horizontal, high-angle, and vertical wells in the tight, fractured Devonian shales of West Virginia. The optimal drilling method was determined by economic and production comparisons of simulation results from studies of unstimulated and stimulated wells of the following types: a single horizontal well, a single high-angle well, and up to four vertical wells. Infill drilling was compared to new-lease wells, and the effect of faulting on predicted gas production was studied. The study showed that new-lease horizontal drilling is the optimal method in West Virginia, and high-angle drilling results in a slight improvement over vertical drilling. Horizontal drilling showed as much as a 46 percent improvement in production performance over both vertical and high-angle drilling for new-lease wells. Economically, a single 2,000-ft (6.096 × 102 m) horizontal well revealed a ROR of 40 percent and payout of 1.6 years as compared to 11.2 percent, 4.9 years and 4.1 percent, 7.8 years for single new lease vertical and 60° high-angle wells, respectively.

Keywords:
horizontal well, vertical well, hw 1000, reservoir simulation, complex reservoir, high-angle well, upstream oil & gas, appalachian basin, infill drilling, gas production
Subjects:
Reservoir Simulation, Unconventional and Complex Reservoirs, Shale gas
Copyright 1989, Not subject to copyright. This document was prepared by government employees or with government funding that places it in the public domain.
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