The purpose of this case study was to illuminate the morphology of a prolific sand trend across SM Energy's acreage and better define the edges of the trend away from well control via seismic reservoir characterization. This was accomplished by using a quantitative analysis workflow of post stack seismic attributes in a strata-grid that encompasses the reservoir interval. The methods used include spectral decomposition, well log upscaling, neural network prediction and interactive geobody detection through cross-plotting. The results were validated with blind wells from the study area. In this study, not only the workflow employed and its results are discussed, but also our attempts to avoid spurious correlation, possible sources of error in the porous sand prediction and how the resulting attribute-derived porous sand map was used.
Within the last several years, the Anadarko Basin wash play has undergone a renaissance largely due to the utilization of horizontal drilling and completion techniques. The play has been considered difficult to interpret both geologically and geophysically. Consequently, the application of seismic attribute analysis to mid-continent washes has not been widely published. SM Energy's mid-continent granite wash asset covers a portion of a prolific Missourian age wash trend in Wheeler County Texas. In 2010, a competitor drilled a successful horizontal well, Well #1, in the interval with initial production rates of approximately 900 BOPD and about 1.1 million CFGPD (Figure 1). Adequate well control existed to generally map the trend across our acreage (nearly 40 vertical wells); however some uncertainty remained regarding the extent of the sand trend in areas that lacked well control. In order to gain insight into areas away from well control as well as assess potential areas of economic value across our acreage, a seismic attribute study was conducted over a 14 square mile portion of SM Energy's 3D seismic holdings.