Prediction of tensile fractures in KS2 trap, Kuqa Depression, NW China

Abstract

Abstract Tectonic fractures that generally controlled by tectonic stress field, especially tensile fractures, are crucial for tight reservoirs that are characterized by low porosity and low permeability. Prediction of fracture distribution is extremely important for further exploration and development of such reservoirs. Tensile fractures are developed in the upper Bashijiqike Formation in Kuqa Depression in Northwest China. The subject of this study was the KS2 faulted fold, and the characteristics of the tensile fractures were analyzed in detail. A three-dimensional finite element elastic model of the faulted fold was constructed, and the two-factor method was applied to predict the distribution of tensile fractures in the upper Bashijiqike Formation in the faulted fold. Distributions of predicted tensile fractures reveal that positions relative to the fold axis and faults in the hinge zone both have significant influence on the distribution of tensile fractures. The predicted tensile fractures are developed in the hinge zone in the faulted fold, particularly in the area around fault tips, which is the region with the most potential for oil and gas exploration in faulted folds.