东海西湖凹陷孔雀亭地区断裂封闭性定量评价

Quantitative Evaluation of Fault Sealing Property in Kongqueting Area of Xihu Sag, East China Sea

杨超 庄建建 张如凤 杨海 张书迪

YANG Chao ZHUANG Jianjian ZHANG Rufeng YANG Hai ZHANG Shudi

中国石油化工股份有限公司上海海洋油气分公司勘探开发研究院，上海　200120

Institute of Exploration and Development, SINOPEC Shanghai Offshore Oil & Gas Company, Shanghai 200120, China

以东海西湖凹陷孔雀亭地区为研究对象，在结合区域地质背景的基础上，参考前人对断裂封闭性的研究成果，通过统计断面倾角、计算断面正压力，并结合断裂带泥质含量，计算断裂封闭性指数，对孔雀亭地区发育的多条断裂的封闭性进行定量评价。研究结果表明，封闭性最好的为牡一断裂，较差的为孔一断裂。高带至低带由于埋深影响，断面正应力整体呈现增大的趋势，断裂封闭性指数逐渐增大。不同断层和同一断层不同部位封闭性之间存在差异，主要受断层倾角、断距、断层走向及断裂带泥质含量影响。现今的油气显示可作为判断断层封闭性的有效依据，结合断层封闭性指数特征，最终确定了该区油气断层封闭指数下限为8.0。该文对孔雀亭地区断层封闭性与含油气特征之间关系的探索，可为该地区后续圈闭评价及井位部署提供参考。

Taking Kongqueting area of Xihu Sag in East China Sea as the research object, referring to previous research results, the fault sealing property is quantitatively evaluated based on the regional geological condition, by calculating the dip of fault and the positive sectional pressure, combining with the shale content of fault zone, and calculating the fault sealing index. The result shows that the best sealing is the Fault Muyi and the worse is Fault Kongyi. From the high zone to the low zone, the positive sectional pressure increases due to the influence of burial depth and the fracture sealing index increases gradually. There are differences between different faults and different parts of the same fault, which are mainly affected by the dip of fault, fault distance, fault strike and the content of mud in fault zone. Today's hydrocarbon display can be used as an effective basis for judging fault sealing. Combined with the characteristics of fault sealing index, the lower limit of oil and gas fault sealing index in this area is finally determined to be 8.0. The study on the relationship between fault sealing and hydrocarbon characteristics in Kongqueting area can provide reference for subsequent trap evaluation in the next well location target.

https://doi.org/10.3969/j.issn.1008-2336.2023.02.007