C. C. Decalf
Texas A&M University, Dept. of Geology, College Station, TX
A trend ofWolfcampian-Leonardian carbonate buildups is located in the southwestern Midland Basin, Upton County, Texas. The buildup trend is located east of the eastern faulted margin of the Central Basin Platform and north of the Ozona Arch. Carbonate deposition began during lowstand times, within or just below wave base. In the Southwestern Midland Basin, the Wolfcampian-Leonardian carbonate interval is lithologically heterogeneous due to the presence of abundant lithoclastic debris that was shed from the uplifted Central Basin Platform. The lithologic heterogeneity makes it difficult to identify the buildups on seismic profiles. Several inferred buildups have been drilled in the past, but many boreholes only penetrated lithoclastic facies, not true buildup facies.
Analyses of various seismic attributes were conducted for the Wolfcampian-Leonardian interval in the SW Midland Basin in an attempt to improve the recognition and imaging of the carbonate buildups. The objective was to identify a set of attributes that directly indicate the buildup locations. After extensive trail of various attributes, the variance attribute was selected as the optimum seismic attribute. The resultant 3-D variance volume was used to detect the buildup locations, and some aspects of their internal stratigraphy, and to establish the fault framework in the Amacker survey. The instantaneous frequency attribute, combined with the variance attribute was also marginally useful for imaging the buildups.
AAPG Search and Discovery Article #90902©2001 AAPG Foundation Grants-in-Aid