地学前缘 ›› 2012, Vol. 19 ›› Issue (2): 212-220.

• 论文 • 上一篇    下一篇

页岩裂缝发育主控因素及其对含气性的影响

 丁文龙, 李超, 李春燕, 许长春, 久凯, 曾维特   

  1. 1. 中国地质大学（北京） 能源学院， 北京 100083 2. 中国地质大学（北京） 海相储层演化与油气富集机理教育部重点实验室， 北京 100083 3. 中国石化勘探南方分公司， 四川 成都 610041
  • 收稿日期:2011-11-18 修回日期:2012-02-15 出版日期:2012-03-25 发布日期:2012-03-25
  • 作者简介:丁文龙（1965—），男，副教授，博士后，主要从事石油构造分析与控油气作用、页岩气构造和裂缝及其与含气量关系等方面的教学与科研工作。E-mail:dingwenlong2006@126.com
  • 基金资助:

    国家自然科学基金项目“中国南方下古生界海相富有机质页岩裂缝发育程度与主控因素定量关系研究”（41072098）；国家科技重大专项专题“渤海湾盆地页岩气资源评价”（2011ZX0501800101HZ）；全国油气资源战略选区调查与评价国家专项“中国重点地区页岩气资源潜力及有利区优选”（2009GYXQ15）

Dominant factor of fracture development in shale and its relationship to gas accumulation.

 DING  Wen-Long, LI  Chao, LI  Chun-Yan, HU  Chang-Chun, JIU  Kai, CENG  Wei-Te   

  1. 1. School of Energy Resources, China University of Geosciences(Beijing), Beijing 100083, China 2. Key Laboratory for Marine Reservoir Evolution and Hydrocarbon Abundance Mechanism, Ministry of Education, China University of Geosciences(Beijing), Beijing 100083， China 3. China Petroleum and Chemical Corporation Exploration Southern Company, Chengdu 610041, China
  • Received:2011-11-18 Revised:2012-02-15 Online:2012-03-25 Published:2012-03-25

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摘要：

依据国内外页岩气大量资料和测试数据，对影响页岩裂缝发育的岩性和矿物组成、有机碳含量、岩石力学性质、异常高压等非构造因素和构造因素进行了定性或半定量分析，初步探讨了页岩裂缝发育与含气量之间关系。结果表明：页岩中石英、长石和碳酸盐岩含量高，岩石的泊松比低、杨氏模量高，脆性大，容易在外力作用下形成天然裂缝和诱导裂缝，其发育程度一般与页岩中脆性矿物的含量呈正相关关系。高有机碳含量或异常高压页岩裂缝发育。裂缝发育程度与有机碳含量关系可以划分为4类。页岩裂缝发育程度与总含气量和游离气量呈正相关关系，页岩裂缝越发育，其含气量越大，产气量也越高。裂缝对页岩气藏的形成具有双重作用，一是裂缝可以作为天然气和地层水的有效储集空间和快速运移通道,有利于页岩层系中游离态天然气体积的增加和吸附态天然气的解吸，裂缝密度越大，走向越分散，产气量越高；二是裂缝规模过大,可能导致天然气散失。北美地区页岩裂缝发育带内的页岩气勘探成功率高，产气量高，中国四川盆地下古生界海相富有机质脆性页岩层中天然气有良好显示或高产气井均与裂缝发育密切相关。

关键词: 页岩, 裂缝, 主控因素, 含气量, 产气量

Abstract:

Shale with high quartz, feldspar and carbonate will have low Poisson’s ratio, high Young modulus and high brittleness. As a result, the shale is conducive to produce natural and induced fractures under external forces. In general, there is a good correlation between fracture development in shale and the volume of brittle minerals present. Shale with high TOC or abnormally high pressure has welldeveloped fractures. Shale fracture development also shows a positive correlation with total gas accumulation and free gas volume, i.e., the better shale fractures are developed, the greater the gas accumulation and therefore the higher the gas production. Fractures provide migration conduits and accumulation spaces for natural gas and formation water, which are favorable for the volumetric increase of free natural gas. Wider fractures in shale result in gas loss. In North America, there is a high success ratio of shale gas exploration and high gas production from highangle fracture zones in shale. Good natural gas shows or high yield producers in the Lower Paleozoic marine organic matterrich rocks in the Sichuan Basin are closely related to the degree of fracture development in brittle shales.

Key words: shale, fracture, dominant factor, gas accumulation, gas production

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