
第38卷第2期 2017年4月
文章编号:10013873(2017)02-012706
新疆有油地质
XINJIANC PETROLEUM CEOI.OCY DOI:10.7657/XJPG20170201
Vol.38.No.2
Apr.2017
临南洼陷江家店地区沙三下亚段储集层成岩流体演化
操应长,王新桐,王艳忠,杨田,程鑫,王思佳
(中国石油大学地球科学与技术学院,山东青岛266580)
要:通过对临南注陷江家店地区10余口并的70余块样品的铸体薄片分析,流体包裹体特征总结及显微测温,揭示摘
了沙河街组沙三下亚段储集层在埋截过程中,经历了多期次的酸碱流体演化及油气完注:距今43.7x10°-—37.0x10°a,地层流体呈弱碱性,成岩作用以压实作用为主,并发育少量早期黄铁矿胶结物;距今37.0x10°—28.2x10°a,有机质热演化导致地层流体星酸性,发生长石的溶蚀及石美的I期次生加大现象;距今28.2×10—24.6x10°a,有机开始脱骏,沙四下亚役的石膏层开始脱水,地层水变为碱性,发生石英溶解及碳酸盐矿物的胶结现象;距今24.6×10一14.0x 10°a,有机质热演化使地层水持续星酸性,发生长石、碳酸盐胶结物的溶蚀及石英的Ⅱ期次生加大现象;距今14.0x10一 2.8x10°a,烃源岩再次演化生烃,地层水持续星酸性;2.8x10°a至现今,地层水呈弱碱性,发育少量的晚期黄铁矿胶结物。关键调:济阳地陷;惠民凹陷;临南洼陷;沙河街组;成着流体;油气充注;流体包豪体
文献标识码:A
中图分类号:TE112.221
Evolution of Diagenetic Fluids in Reservoirs of Es in Jiangjiadian Area of Linnan Sag
CAO Yingchang,WANG Xintong, WANG Yanzhong, YANG Tian, CHENG Xin,WANG Sijia
(School of Geosciences, China University of Petroleum, Qingdao, Shandong 266580, China)
Abstract: Based on the thin section analysis, fluid inclusion summarizing and mierothermometry for more than 70 pieces of samples ob-tained from more than 10 wells in the Jiangjiadian area of Linnan sag, the paper reveals that the Esi reservoir of Shahejie formation under-went multi periods of acid-base fluid evolution and hydrocarbon charging during its burial process: 43.7x10° a — 37.0x10° a ago, the forma-tion fluid was weakly alkaline, the diagenesis was dominated by compaction and a few early pyrites occurred; 37.0x10° a— 28.2x10° a ago, the themal evolution of organic matter led to the acidity of formation fluid, and feldspar dissolution and the first phase of quartz overgrowth took place; 28.2×10° a—24.6x10° a ago, decarboxylation of organic acid as well as dehydration of gypsum bed in the lower Sha-4 member occurred, thus the formation water became alkaline, and carbonate cementation and quartz dissolution were noted; 24.6x10° a-14.0x10° a ago, thermal evolution of organic matter made the formation water acidic and the second phase of acid dissolution and quartz overgrowth be-gan; 14.0x10° a—2.8x10° a ago, re-evolution and hydrocarbon generation happened to the source rocks, which made the formation water continuously acidic; since 2.8x10° a ago till now, the formation water was acidic and a few late pyrite cements were found.
Keywords: Jiyang depression; Huimin sag: Linnan sag; Shahejie formation; diagenetic fluid; hydrocarbon charging; fluid inclusion
包裹体是至今仍包裹在矿物晶格缺陷或者穴窝中,与主矿物之间存在明显“相"界线的物质"。由于其内部流体的稳定性,包裹体在大多数情况下不会因为外界地质环境的改变而发生改变,因此,通过对其物理及化学特性的研究,可以推断其形成时的地质环境,从而成为了解盆地古流体及其活动的重要依据。
临南洼陷江家店鼻状构造带是油气运聚的主要地区,以构造油气藏及岩性油气藏为主"。近年来,些学者对江家店地区渐新统沙河街组沙三下亚段的储集层进行了研究,认为其成容作用主要包括压实作用、胶结作用、交代作用及溶解作用,储集层孔隙以次生孔为主,尤以长右落孔含量最高,但是由于储集
收稿日期:2016-09-21
修订口期:201612-23
层在演化过程中历经多期溶蚀、胶结以及复杂的交代作用,导致物性发生了复杂的变化3-9。本文通过分析成岩作用类型及成岩流体性质,结合砂体沉积埋藏演化史以及有机质热演化史,明确江家店地区沙三下业段储集层的成岩流体演化规律,盲在对研究区今后的油气勘探开发有所神益。
区域地质概况
临南洼陷是济阳坳陷惠民凹陷西端的一个次级
构道单元(图1),南界的夏口断层系和北界的临邑断层系呈雕形排列"。临南洼陷古近系自下而上发育有古新统孔店组、渐新统沙河街组和东营组,沙河街
基金项目:国家自然科学基金(41402095):国家科技重大专项(2016ZX05006-007):中高校基本科研业务费专项资金(16CX02027A) 作者简介:操应长(1969-).男,安徽潜山人.教授.博士生导师.沉积学、层序地/公学及储层地质学,(Tel)13505325516(E-mail)
caoych@upc.edu.cn
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