Development characteristics and petroleum geological significance of tearing faults in Hashan area

Abstract

Hashan area is part of piedmont thrust belt in northwestern Junggar basin. By studying its structural characteristics, it is found that there are three different deformation sections along the strike of tectonic belt. It is considered that the development of tearing faults is the main reason for controlling the difference of structural deformation in different sections of Hashan area. In order to study the characteristics and petroleum geological significance of tearing faults, the identification and structural characteristics of tearing faults are studied, combined with the analysis of petroleum geological conditions, its petroleum geological significance is found out.The results showed that: The tearing faults in the Hashan area are usually developed in the position where the strike of the main reverse fault changes. The strike is mainly NW-trending and is roughly perpendicular to the long axis of the main structure. The terrain on both sides of the fault has obvious dislocation or belongs to different terrains, and is mostly presented flower-like structure or steep cliff on the profile. The lateral compression during the formation of the piedmont zone leads to the differential nappe of different structural parts of the same block, which is the main reason for the formation of tearing faults in Hashan area. The late tearing faults of nearly north-south direction in Hashan area communicated deep source rocks downward, Jurassic blanket sand upward and formed traps laterally, which played an important role in controlling hydrocarbon accumulation.