【摘要】 依据塔中地区地震资料解释的断裂体系、中下奥陶统顶底界面古构造图和40多口井裂缝特征统计等成果,在对塔中地区中下奥陶统碳酸盐岩声发射地应力测量、岩石力学参数和单轴抗拉强度测试的基础上,考虑断裂对裂缝形成的影响,采用三维有限元法对塔中地区中下奥陶统加里东中期裂缝形成期的古构造应力场进行模拟。结果表明:裂缝形成期地应力的最大主应力有效值为51.8～62.4MPa,平均值为57.0MPa,抗张强度为4.13～8.02MPa,平均值为5.75MPa;有效张应力高值区是构造裂缝储层发育的有利区和较有利区,主要分布在大的断裂带交汇处和断裂带的部分区段内,与实际钻井统计的中下奥陶统裂缝线密度和油气井分布区基本吻合,可以为研究区的油气勘探提供新的地质依据。更多还原

【Abstract】 Based on the fracture systems interpreted from seismic data,paleo-tectonic map of bottom and top surface of middlelower Ordovician and cores fracture parameters statistics from over 40 wells,the middle-lower Ordovician carbonate reservoirs in Tazhong area were studied from analysis of acoustic emission,stress measurement,rock mechanics parameters and uniaxial tensile test. Considering the influence of faults on the fracture forming,3-D finite element method was applied to simulate paleostructural stress field of the middle Caledonian in Tazhong area. The simulation results show that during fracturing the maximum principal stress effective value ranges from 51. 8 to 62. 4 MPa,with the average value of 57. 0 MPa,and the tensile strength ranges from 4. 13 to 8. 02 MPa,with the average value of 5. 75 MPa. High value area of effective tensile stress is the favorable area for structural fractured reservoirs development,and most distributed in the interchange area of large fractured belts and part of the section of fractured zone. The distributed zone coincides with oil and gas wells and the Ordovician fracture-developed zone defined by fracture linear density statistic data from actual drilling,which provides new geological evidences for oil and gas exploration of the area.更多还原