Challenge Facing Oil Explorers in Nevada

Abstract

Can operators in Nevada maintain the current trend of rising oil production In October 1990, Nevada oil production averaged over 11,500 b/d, up about 30% from 1989 average daily production and double 1985 rates. This extraordinary surge reflects improvements in the understanding of Nevada's unique oil-field geology. Future increases in production will result from meeting geological, geophysical, and engineering challenges, such as the following. (1) Enhancing subsurface structural imaging. Integration of outcrop geology, borehole geology, and remote sensing with seismic, potential field, and electrical geophysics will improve structural interpretations. (2) Predicting pre-Miocene subcrop stratigraphy. Better understanding of complex Mesozoic and Tertiary structural overprinting, combined with additional well control, will permit more precise balancing of cross sections. Such sections will better predict the position of reservoir-quality rocks relative to sealing surfaces like the pre-Miocene unconformity. (3) Understanding local thermal histories and source rocks. Mapping variations in present and past heat flow, along with local source rock quality will allow better judgment as to whether oil and gas may have been generated and preserved in a given area. (4) Optimal handling of fluid-sensitive reservoirs. Use of air drilling has doubled production rates at Trap Spring field and may give similar results inmore » other sensitive reservoirs. Application of sound geological and geophysical concepts and advances in drilling and completion technology will allow Nevada operators to find and develop significant new oil reserves in the 1990s.« less