辽北张强地区燕山期以来主要构造运动期最大主应力的测定

A Measurement of Maximum Principal Stresses of Main Tectonic Phases in the Zhangqiang Area, Northern Liaoning Province Since the Yanshanian Movement

辽北张强地区晚侏罗世以来经历了4期主要构造运动:燕山早中、晚中、晚期和喜马拉雅晚期,通过声发射(AE)法测得相应4期的最大主应力值分别为106.2MPa、87.3MPa、57.1MPa及33.4MPa,同时还测得现今地应力最大主应力值为17.4～23.3MPa。发现有岩浆活动的构造运动期古应力最大主应力值偏大。油田内含油构造和出油井现今地应力最大主应力值偏低。本区油气成藏期古应力状态的最大主应力值是87.3MPa。

The Zhangqiang area has undergone 4 tectonic phases since the Late Jurassic: the early Middle, late Middle and Late phases of the Yanshanian, and the late phase of the Himalayan. By using the AE method, the authors have measured the corresponding maximum principal stress values of the 4 phases, which are 106. 2 MPa, 87. 3 MPa, 57. 1 MPa and 33. 4 MPa, respectively. Meanwhile, it has been determined that the present -day maximum principal stresses range between 17. 4 to 23. 3 MPa. It is also found that the values of palaeostress are larger for the tectonic phases accompanied by magmatic activities, while those of the present-day stress are smaller for oil -bearing structures and oil producing wells in the oil fields. The maximum principal stress occurring in the formation phase of petroleum accumulation in the area is 87. 3 MPa.