沾化凹陷古近系超压特征及其成因机制  

Genesis and characteristics of Paleogene overpressure in Zhanhua Depression,Jiyang Sub-basin

作　　者：刘华 袁飞飞[1,3] 蒋有录 郝雪峰 方旭庆[4] LIU Hua;YUAN Feifei;JIANG Youlu;HAO Xuefeng;FANG Xuqing(Shandong Provincial Key Laboratory of Deep Oil and Gas, Qingdao 266580, China;Laboratory for Marine Mineral Resources, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China;School of Geosciences in China University of Petroleum (East China), Qingdao 266580, China;Research Institute of Exploration and Development, Shengli Oilfield Company, SINOPEC, Dongying 257000, China)

机构地区：[1]山东省深层油气重点实验室,山东青岛266580 [2]海洋国家实验室海洋矿产资源评价与探测技术功能实验室,山东青岛266071 [3]中国石油大学(华东)地球科学与技术学院,山东青岛266580 [4]中国石化胜利油田分公司勘探开发研究院,山东东营257000

出　　处：《中国石油大学学报（自然科学版）》2021年第3期23-32,共10页Journal of China University of Petroleum(Edition of Natural Science)

基　　金：国家科技重大专项(2016ZX05006-003);国家自然科学基金项目(41772136)。

摘　　要：根据沉积速率、泥岩体积分数、源岩演化程度,对沾化凹陷超压特征及其成因机制进行研究。结果表明沾化凹陷具有多洼、多层系超压发育的特征,最大压力系数可达1.8,纵向上超压发育层系与沙一段、沙三段和沙四段烃源岩层系对应,平面上则与渤南次洼、四扣次洼和孤北次洼等生烃中心相对应;欠压实作用和生烃作用是研究区超压形成的主要原因,其中泥岩体积分数高于85%和沉积速率高于200 m/Ma是欠压实增压的必备条件,随着烃源岩生烃强度和成熟度的增加,生烃增压作用所占比例上升,成为超压成因的主导因素。当烃源岩Ro小于0.7%时,以欠压实增压作用为主,压力系数多小于1.5,且油气多聚集在源内层系中;当生烃区烃源岩成熟度Ro大于0.7%时,生烃增压作用逐渐变得重要,压力系数多大于1.5,且该烃源岩生成的油气多富集在超压层系之上。According to sedimentation rate,mudstone content and source rock maturity,overpressure characteristics and its genetic mechanisms were analyzed.Results show that max overpressure coefficient reaches 1.8 and overpressure develops in Es1,Es3 and Es4,corresponding to three sets of source rocks vertically in Zhanhua Depression.The overpressured area is corresponding to Bonan Sag,Sikou Sag and Gubei Sag.Disequilibrium compaction and hydrocarbon generation are two main genetic mechanisms of overpressure in Zhanhua Depression,which play a role dependent on thermal maturation of source rocks.Mudstone content over 85%and sedimentation rate higher than 200 m/Ma are essential for disequilibrium compaction overpressure.Disequilibrium compaction overpressure is the main overpressure generation mechanism when Ro<0.7%,causing lower than 1.5 overpressure coefficient and hydrocarbon accumulation within source rock layer.Overpressure coefficient is over 1.5 when Ro>0.7%,then hydrocarbon generation becomes the main genetic mechanism,and hydrocarbon accumulates above the overpressure layer.

关 键 词：异常流体压力 欠压实增压作用 生烃增压作用 超压成因机制 沾化凹陷 

分 类 号：TE12[石油与天然气工程—油气勘探]