CHARACTERISTICS OF BREAKTHROUGH PRESSURE OF MESOZOIC-PALEOZOIC COVER IN JIANGSU LOWER YANGTZE AREA
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摘要: 江苏下扬子区震旦系—第三系发育多套盖层,包括寒武系下统幕府山组、志留系下统高家边组、白垩系上统浦口组区域性盖层等。泥岩盖层的突破压力主要受泥岩孔隙中微孔隙和小喉道分布的控制;统计表明,盖层的突破压力随埋深的增加先是由小变大,埋深继续增加又由大变小,说明突破压力受成岩演化控制。利用吸附法获得的吸附—脱附等温线来测定微孔结构的研究表明,盖层突破压力的变化与泥岩在不同演化阶段的微孔隙结构有关。在较低的演化阶段,泥岩具有孔隙型毛细孔结构特征,在压实作用下,孔隙度逐渐变小,突破压力不断增加。当到达较高演化阶段时,泥岩脆性增加,在地应力作用和抬升作用下,产生微裂隙,突破压力不断变小,封盖能力逐步降低。Abstract: Sets of cap formations have generated from Sinian to Tertiary in the Jiangsu Lower Yangtze area,such as-C1mu,S1g and K2p.Breakthrough pressure of mudstone caprock is mainly controlled by distribution of micropores and small throats.Statistics have shown that as burial depth increases,breakthrough pressure increases at first and then decreases,indicating the controlling effect of diagenesis on breakthrough pressure.Adsorption and desorption isotherms of microporosity have proved that caprock breakthrough pressure changes due to micropores structures of mudstone during different evolution stages.During the lower stage,mudstone is characterized by pore-type structure and breakthrough pressure increases with depth.During the higher stage,mudstone brittle increases and micro-fissures come into being,resulting in decreases of breakthrough pressure and sealing ability.
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Key words:
- breakthrough pressure /
- diagenesis /
- mudstone caprock /
- Mesozoic-Paleozoic /
- Lower Yangtze area /
- Jiangsu Province
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[1] 丁道桂,王东燕,刘运黎.下扬子地区古生代盆地的改造变形[J].地学前缘,2009,16(4):61-73. [2] 范小林,方成名.苏北盆地深层古生界结构与海相油气勘探[J].石油实验地质,2008,30(5):435-438. [3] 佘晓宇,徐宏节,何治亮,等.江苏下扬子区中、古生界构造特征及其演化[J].石油与天然气地质2004,25(2):226-236. [4] 刘士林,肖焕钦.中国东部盆地喜山运动Ⅱ幕研究现状及问题[J].石油实验地质,2008,30(2):121-126. [5] 林小云,刘建.中、下扬子区构造演化与海相地层成藏主控因素分析[J].石油天然气学报(江汉石油学院学报),2006,28(6):23-26. [6] 叶舟,梁兴,马力,等.下扬子独立地块海相残留盆地油气勘探方向探讨[J].地质科学,2006,43(3):523-544. [7] 秦顺亭.江苏下扬子区中—古生界的成藏条件及勘探思路[J].海相油气地质,1998,3(1):6-10. [8] 郭念发,尤效忠,刘德法.下扬子区古生界油气地质条件及勘探选区[J].石油勘探与开发,1998,25(1):4-7. [9] 付广,张建英,赵荣.泥质岩盖层微观封闭能力的综合评价方法及其应用[J].海上油气地质,1997,2(1):36-41. [10] 周文,刘文碧,程光瑛.海拉尔盆地泥岩盖层演化过程及封盖机理探讨[J].成都理工学院学报,1994,21(1):63-70. [11] 朱盘良,张文达,陈伟钧,等.天然气盖层微孔隙形态的研究方法及其地质意义[J].石油实验地质,1994,16(2):172-179. -
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