Abstract:

Laojunmiao structural belt is located in Cenozoic foreland thrust belt of south margin,  Jiuquan basin,which is superposed over the south uplift and Shida depression of Early Cretaceous faulted basin. The author adopts the structural stress numerical simulation analysis in this article, and makes the stress analysis separately based on the Cenozoic planar fault system and NE geological profile of Laojunmiao structural belt. Through contrast with the oil distribution area, we can draw the conclusion as the following: X-displacement field shows that fault displacement in the west of structural belt is characteristic of left-lateral slip component; The middle of the structural belt mainly consists of thrust faults; In the east, the fault displacement has the component of right-lateral strike slip; for the Y-displacement, it is characteristic of leftlateral slip. Low stress areas which are surrounded by high stress in the Laojunmiao structural belt are the most advantageous oil accumulation regions. We should take these stress traps as an emphasis in the process of oil exploration, such as low stress traps in Miaoxi anticline, the middle clamping piece, the bottom part of Laojunmiao thrust belt and the wing of Laojunmiao anticline.

Key words:  Jiuquan basin,  , Laojunmiao structural belt, numerical simulation, stress trap