Applying Curvature and Fracture Analysis to the Placement of Horizontal Wells: Example from the Mabee (San Andres) Reservoir, Texas

摘要

San Andres carbonate reservoirs have long been known to havea high degree of reservoir heterogeneity and poor recovery efficiencies.Fractures are one of several causes of this heterogeneity.The heterogeneity causes unpredictability in water and CO2flooding. However, the correct placement of horizontal wells cantake advantage of this problem.An integrated reservoir characterization study of the Mabeefield incorporating oriented core, Formation Microscanner (FMS)wireline logs, seismic time slices, production character, curvatureanalysis, and interference testing was used to predict fractureorientation and areas of highest fracture density. These fracturecharacteristics were then applied to determine horizontal well locationand orientation. Fracture orientation was evaluated throughthe analysis of oriented core, FMS logs, and interference testing,indicating a fracture orientation of N70W. Analysis of the inducedfractures in the oriented core indicates that the direction of maximumhorizontal compressive stress is N45E. High fracture densitywas delineated by curvature analysis, relative seismic amplitude,and areas of higher production. Areas with high curvature correspondto areas of high relative seismic amplitude and higherproduction. The data integration indicates that four areas have highfracture density. The synthesis of fracture orientation and density,along with the production character, indicates the optimal locationand orientation of horizontal wells.