Structural characteristics and tectonic evolution of Mesozoic-Cenozoic faults in the Shunbei area, Tarim Basin

Abstract

Oil and gas resources in the Shunbei area of the Tarim Basin are rich in Paleozoic strata.Recent petroleum exploration indicates that Mesozoic-Cenozoic sedimentary rocks have a good potential in hydrocarbon extraction. In this study, recently acquired 3D seismic surveys were used to systematically analyze fault types, geometrical characteristics, and evolution of Mesozoic-Cenozoic faults in the Shunbei area. The objective is to understand the characteristics and development mechanisms of faults that have the key controlling factors of hydrocarbon accumulation.In the Shunbei area, the dominant faults are tensional normal faults with few thrust faults and strike-slip faults. The district has many small scale, disorderly distributed faults. Combined with the regional setting and basin evolution stage, we suggest that the development of Mesozoic-Cenozoic faults in the Shunbei area experienced three tectonic cycles during the Indosinian, Yanshanian, and Himalayan periods. The structural position, middle Permian igneous rocks, and the sandy mudstone of the Lower Triassic Tongketuer Formation have significant control on fault evolution.Detailed interpretation of faults in the T90-T50 stratigraphic interval in the Shunbei area shows that the central part of the No.5 fault and south central part of the No.7 fault are two large faults that connect downward to the source rock of the basin. In these two areas, some faults cut upward through T90 to T50, which is good forvertical migration of hydrocarbon from Paleozoic to Mesozoic-Cenozoic strata and therefore are ideal locations for petroleum exploration.

Keywords

• faults
• tectonic evolution
• mesozoic-cenozoic
• shunbei area
• tarim basin