Formation And Evolution Of Strike-slip Fault System Of The Tahe Oil Field

The Tahe Area plays an significant role in oil and gas exploration and development in Tarim Basin and is an important oil and gas producing area in China in the future.There are a large number of strike-slip faults in The Tahe Area.The existing exploration studies show that the distribution of oil and gas is closely related to the development of strike-slip faults.Therefore,it is particularly important to study the formation and evolution of strike-slip faults in The Tahe Area.In this paper,on the basis of the theory of generalized fault(put pre-existing structure under the condition of faulting mode),using 3 d seismic data of the Shiquxi and the Shiquxi area about the Tahe oil field on the flat profile characteristics of strike-slip faults in the study area,activity time and section analyze the structure of the system,and further validated by analogue modelling analysis,has obtained the following understanding:(1)in The Tahe Area can be divided into two major strike-slip fault system: the south(the Shiquxi area)development of typical symmetric "X" type conjugate strike-slip fault system and north(the Yuqi 8 well area)development is not symmetric conjugate strike-slip fracture system,and two major strikeslip fault system in the aspects of formation and evolution of the genetic mechanism exists obvious difference;(2)The formation and evolution of strike-slip fault system in The Tahe Area can be divided into three stages:(1)middle Caledonian southern The Tahe Area formed NNE and NNW towards the "X" type of symmetric conjugate strike-slip fault system,the maximum principal compressive stress direction for N3 ° E,no obvious faulting period of the northern,(2)the late Caledonian,Hercynian in The Tahe Area development in northern NE to give priority to with a small amount of SN strike fault not symmetric conjugate strike-slip fracture system,The direction of the maximum principal compressive stress is N23°E,and some preexisting structures in the southern region are revived.(3)The Indosinian Yanshanian revived the early strike-slip fault systems as preexisting structures,and there were echelon normal faults related to strikeslip faults in both the north and south regions.The maximum principal compressive stress direction was N37°E during this period.(3)The analogue modelling results of the "X" type fault revival of the Hercynian and Indosinian Yanshan periods match the prediction results of mole space completely,and are similar to the geological characteristics,indicating that the activity of preexisting faults in different trends is different and can be predicted after the direction of maximum principal stress changes.(4)The same strikeslip fault is evaluated from the perspective of structure.It can be seen that the longer the active time in different sections,the greater the activity coefficient(the larger the fault distance and the wider the width of the fault System),and the better the development degree of the reservoir.Based on the above quantitative prediction of strike-slip fault profile characteristics,formation and evolution,fault activity strength and subsection analysis,it can provide theoretical guidance for the next exploration and development of the Tahe oilfield.