Fine characterization of Ordovician inner fault-controlled bodies in area A of Tarim Basin

Abstract

It is a major difficulty to accurately characterize the inner fault-controlled bodies in the exploration and development of fault-controlled oil and gas reservoirs because the fault-controlled bodies are diverse in reservoir space， complicated in structure， and highly heterogeneous in reservoir space， which affects the exploration and development of the oil and gas reservoirs. The seismic， logging， and other data are integrated and the inner breccia zones and intercluster fracture zones of caverns-like were finely characterized in this paper. The grid structure models of the fault-controlled bodies caverns-like were established and their contours were described with seismic multiple attributes； the image analysis was fully combined with mathematical statistics by a self-compiled program and the core and wing regions of the caverns-like were defined by the parameters such as the location and width of the breccia and intercluster fracture zones； the development scales of the breccia zones and intercluster fracture zones in different parts of caverns-like were determined. The results show that the cluster-filled grid structures of caverns-like are composed of the breccia zones， intercluster fracture zones， and intergrid matrix， and the reservoir properties of breccia zones is better than those of intercluster fracture zones， and they are better than those of the intergrid matrix. The breccia zones and intercluster fracture zones control the reservoir properties of caverns-like， and the multi-cluster grid structures determine the separateness and strong heterogeneity of the reservoirs. Compared with the translation sections， the grid strike bodies in the extrusion sections are counterclockwise offset by 10°， and those in the pull sections are counterclockwise offset by 16°. The spatial distribution models of fault-controlled bodies in this area are established by combining the strike-slip fault caverns-like contours and the inner caverns-like description， which provides a geological basis for efficient exploration and development of other fault-controlled oil and gas reservoirs.

Keywords

• carbonate rock
• fault-controlled body
• fracture-cavity reservoir
• ordovician
• cavern-like
• tarim basin