第38卷第2期 2017年4月
文章编号：10013873(2017)02-0209-06
新疆石油地质
XINJIANG PETROLEUM GEOLOCY DOI:10.7657/XJPG20170216
应用地球化学方法评价断层封闭性
以苏北盆地金湖凹陷坝田地区为例王力"，陈世加"，丁玉盛"，路俊刚"，马捷"，李勇
（1.西南石油大学a.地球科学与技术学院；b.天然气地质四川省重点实验室，成都610500；
2.中国石化江苏油田分公司安徽采油厂，安徽天长239300）
Vol. 38, No.2 Apr.2017
摘要：基于苏北盆地金潮凹陷坝图地区和周缘次以及断层上、下盘原油地球化学特征对比分析，明确主力生烃次凹，判识断层封闭性，分析坝田地区勘探潜力。研究表明，龙岗次凹周缘原油成熟度最高，为烃源岩成熟阶段产物，是坝田地区周缘主力生烃次凹。F断层上、下盘原油正构烷烃、留烷、站烷分布以及成熟度等地球化学特征存在明显差异，竭示F断层处于封闭状态，证实龙岗次四烃源岩所生成的成熟油未越过F，断层运移至坝田地区。坝田地区含油砂鲁抽提物成熟度低，与自身斜坡区烃源岩和汉润次凹、东阳次凹所生成的低成熟阶段产物相似。低成熟阶段烃源
岩生烃量有限，难以形成规模油藏。此，坝田地区勘探潜力较差，而紧邻龙岗次凹的断块图闭是有利勘探目标。关键调：苏北盆地；金湖凹陷；坝田地区；油气地球化学；断层封闭性；勘探潜力
中图分类号：TE112.114
文献标识码：A
Using Geochemical Methods to Evaluate Fault Sealing: A Case Study from Batian Area in
Jinhu Sag, Subei Basin
WANG Li", CHEN Shijia*-b, DING Yusheng", LU Jungang*h, MA Jie", LI Yong"
(1.Southwest Petroleum University ,a.School of Geosciences and Technology, b.Sichuan Key Laboratory of Natural Cas Geology, Chengdu,
Sichuan 610500, China; 2.Anhui Oil Production Plant, Jiangsu Oilfield Company, Sinopec, Tianchang, Anhui 239300, China)
Abstract: Based on the correlation and analysis of geochemical characteristics of oils from Batian area, surrounding sub-sags, the hanging wall and fool wall of the fauit, the paper determines the key subsags for hydrocarbon generation, identifies fault sealing and analyzes the ex-ploration potential of Batian area. The results show that the oil from the periphery of Longgang subsag with the highest maturity is the prod-uct of the source rocks of matured stage, and Longgang sub-sag is the key hydrocarbon generating sub-sag in the periphery of Batian area. The differences of geochemical characteristics such as hydrocarbon's n-alkanes, sterane and terpane distributions and oil maturity in the hanging wall and foot wall of F, fault reveals that F, fault is sealed and the matured oil sourced from Longgang sub-sag never migrates across F, fault to Batian area, The maturity of the extracts from oil-bearing sandstones in Batian area is low, which is similar to the low-ma-turity products sourced from the slope, Chajian sub-sag and Dongyang sub-sag. The hydrocarbon generating amount from the source rocks of low-maturity stage is limited so that scaled reservoirs are dificult te forn. Therefore, the exploration potential is relatively poor in Batian
area and the fault block traps neighboring to Longgang sub-sag should be the favorable exploration targets. Keywords :Subei basin; Jinhu sag: Batian area; petroleum geochemistry; fault sealing; exploration potential
断层封闭性是指断层上、下盘由于岩性、物性的变化，形成排驱压力差异，从而阻碍流体在断层上、下盘流动的性质"-2]。自Smith建立断层封闭性经典模型系统讨论断层封闭性"以来，断层封闭性一直是石油地质研究的重要内容。国内外学者提出了许多研究断层封闭性的方法，主要从断层的形态、几何学、运动学以及断层面的物质涂抹等角度，利用地震、测井以及钻井等基础资料，采用岩性配置关系、压力计算、泥岩涂抹和封堵系数定性或定量评价断层的封闭性，研究方法主要包括参数评价法、地震预测法、地应力法、
收稿日期：2016-10-16
修订口期：2016-12-26
垂向封闭因子法、排替压力法、泥岩涂抹法、烃柱高度法等4-6)。封闭断层上、下盘储集层中的流体不流通因此，文献[7]和文献[8]提出，依据断层上、下盘储集层内流体是否具有相同的物理化学性质，能够更直接地判识断层的封闭性。封闭断层上、下盘储集层为独立系统，其原油性质、天然气组成以及地层水矿化度等流体性质存在差异；而开启断层上、下盘流体可以流通，断层上、下盘的流体性质相同或相似。部分学者不仅采用地球化学方法判断断层的封闭性，还结合生烃演化以及油气的次生变化特征，研究地质历史时
基金项11：国家973项目（2014CB239005）；国家白然科学基金(41502146）
作者简介：王力（1989-），男，四川遂宁人，博士研究生，地质资源与地质.T程（Tel>15198147262(Email)cooler1015@163.eom 万方数据