新庄地区断层封闭性综合评价

新庄油气田位于泌阳凹陷北部斜坡，断层发育，产层呈“叠瓦状”展布，断层封闭性研究对油气田开发有着重要意义。对构造主控断层的岩性对置关系、断层两侧流体性质进行了对比分析，针对典型断层计算其断面压力、断裂带泥质含量，对研究区主控断层封闭性进行了定性和定量的综合评价。同时，在实验室通过模拟地层条件，测试不同围压和孔隙压力下的断层临界开启压力和临界闭合压力，得出新庄地区主控断层的临界开启压力为3.7 MPa、临界闭合压力为6 MPa，而计算的主控断层断面压力不小于6 MPa，过渡埋深400～600 m，断裂带泥质含量40%～55％，这表明绝大多数主控断层的含油气层段（目的层段）封闭性较好，但是在地层埋深不超过200 m时，蒸汽吞吐的注入压力要控制在3.7 MPa以内，以免压力过大造成断层开启，从而影响蒸汽吞吐的最终生
产效果。

INTEGRATIVE EVALUATION FOR FAULT SEALING CAPACITY IN XINZHUANG AREA

Xinzhuang oil and gas field is located in the northern slope of Miyang depression where the faults are very developed and the pay formations are distributed imbricately, therefore, the research on fault sealing capacity has important significance for the exploitation of this oil and gas field. The paper compared and analyzed the lithology contraposition relationship of the main faults and the fluid properties in the two sides of the fault. Aimed at the typical faults, the paper calculated pressure on the fractured surface and shale contents in the fracture zone, and performed qualitative and quantitative integrative evaluation for sealing capacity of the main faults in the study area. Moreover, based on the laboratory simulation results of the formation conditions, the critical open pressure and critical close pressure on the faults are tested with the different surrounding pressures and pore pressures. For the main faults in Xinzhuang area, it is calculated that the critical open pressure is 3. 7 MPa, and the critical close pressure is 6 MPa. The pressure on the fractured surface is not less than 6 MPa, the transition well depth ranges from 400 to 600 m, and the shale content in the fracture zone is between 40% and 55% , which indicates that the oil- and gas-filled layers (the target horizons) in the most main faults have good sealing capacity. However, if the depth of the horizon is less than 200m, the steam injection pressure should be controlled within 3. 7 MPa lest should the fault become open under excessive pressure, thus to affect the final production effects of the cyclic steam injection.