Mapping Surface Alteration Effects Associated with Hydrocarbon Reservoirs at Gypsum Plain, Texas, and Cement, Oklahoma, Using Multispectral Information

Abstract

Two test sites, Gypsum Plain, Texas, and Cement, Oklahoma, were selected to evaluate combined use of airborne visible/infrared imaging spectrometer (AVIRIS) and thermal infrared multispectral scanner (TIMS) for detection of alteration effects associated with hydrocarbon microseepage. Bleaching of redbuds, variations in carbonate cement, replacement of gypsum, exidation of iron, and changes in clay mineralogy may correlate spatially with oil and gas production and subsurface structures. Spectral features due to iron oxides, calcite, gypsum, smectite, and kaolinite can be mapped using AVIRIS image data, using various techniques such as ratios, scene-dependent log residuals, and scene-independent radioactive transfer approach using LOWTRAN7, and with TIMSA data using DSTRETCH. Poor signal-to-noise in the 2.0-2.4 {mu}m region limited the ability to map clay, gypsum, and carbonates both at Cement and Gypsum Plain, carbonate and quartz-rich sediments at Gypsum Plain, and differentiated soils developed on the Rush Spring Sandstone from soil derived from the Cloud Chief Formation at Cement. Combined spectral and photogeologic interpretation of coregistered AVIRIS, TIMS, and Landsat TM, and digital elevation data demonstrate the practical approaches for surface oil and gas exploration using presently operational commercial aircraft and future satellite systems.