特种油气藏 ›› 2021, Vol. 28 ›› Issue (1): 59-66.DOI: 10.3969/j.issn.1006-6535.2021.01.008

• 地质勘探 • 上一篇    下一篇

长宁背斜龙马溪组页岩裂缝发育特征及期次解析

万远飞1,2, 秦启荣1,2, 范宇3, 吴建发3, 赵圣贤3, 季春海3, 范存辉1,2   

  1. 1.西南石油大学,四川 成都 610500;
    2.天然气地质四川省重点实验室,四川 成都 610500;
    3.中国石油西南油气田分公司,四川 成都 610056
  • 收稿日期:2020-05-02 修回日期:2020-11-02 出版日期:2021-02-25 发布日期:2021-04-27
  • 通讯作者: 秦启荣(1964—),男,教授,1985年毕业于成都地质学院地质学专业,2001年毕业于成都理工大学地质工程专业,获博士学位,现从事构造地质及地质工程研究工作。
  • 作者简介:万远飞(1996—),男,2018年毕业于长江大学资源勘查工程专业,现为西南石油大学地质资源与地质工程专业在读硕士研究生,主要从事构造地质研究工作。
  • 基金资助:
    国家科技重大专项“长宁—威远页岩气开发示范工程”(2016ZX05062);中国工程院重点咨询研究项目“中国页岩气规模有效开发途径研究”(2018-XZ-20);中国石油重大科技专项“西南油气田天然气上产300亿立方米关键技术研究与应用”(2016E-0611)

Development Characteristics of Shale Fractures in Longmaxi Formation of Changning Anticline and the Stage Analysis

Wan Yuanfei1,2, Qin Qirong1,2, Fan Yu3, Wu Jianfa3, Zhao Shengxian3, Ji Chunhai3, Fan Cunhui1,2   

  1. 1. Southwest Petroleum University, Chengdu, Sichuan 610500, China;
    2. Natural Gas Geology Key Laboratory of Sichuan Province, Chengdu, Sichuan 610500, China;
    3. PetroChina Southwest Oil & Gasfield Company, Chengdu, Sichuan 610500, China
  • Received:2020-05-02 Revised:2020-11-02 Online:2021-02-25 Published:2021-04-27

摘要: 裂缝特征及形成期次对页岩气有利区优选具有重要意义。以川南地区长宁背斜龙马溪组地层为例,通过对野外露头裂缝的观测分析,结合构造解析、构造反演等手段,对裂缝发育特征及期次展开研究。研究结果表明,长宁背斜以平面剪切缝和剖面剪切缝为主,裂缝发育程度高、倾角大、充填程度高。区内龙马溪组裂缝可分为3套,分别形成于3期构造运动:第1套为NNW、NE向平面剪切缝和近EW向剖面剪切缝,形成于燕山运动中—晚期,以方解石全充填为主;第2套为NW、近EW向平面剪切缝和NE向剖面剪切缝,形成于燕山运动末期—喜山运动早期,裂缝充填物包括方解石及少量泥质、黄铁矿;第3套为近SN、NEE向平面剪切缝和NW向剖面剪切缝,形成于喜山运动中期至现今,裂缝充填程度低,充填物为少量方解石。研究结果为下一步勘探开发提供了一定的理论参考。

关键词: 页岩, 裂缝, 构造分期, 构造演化, 长宁背斜, 龙马溪组

Abstract: Fracture characteristics and formation stages are of great significance for the optimization of shale gas favorable area. For example, we researched the fracture development characteristics and stages of Longmaxi Formation of Changning Anticline in southern Sichuan based on the observation and analysis of outcrop fractures in the field by means of tectonic analysis and tectonic inversion. Results show that the Changning Anticline is dominated by plane shear fractures and sectional shear fractures with high development degree, large dip angle and high filling degree. In this area, fractures in Longmaxi Formation can be divided into 3 types that are formed in 3 stages of tectonic movement. The first type is NNW and NE plane shear fractures and near-EW sectional shear fractures, formed in middle and late stages of Yanshan Movement and fully filled by calcite; the second type is NW and near EW plane shear fractures and NE sectional shear fractures, formed in the final stage of Yanshan Movement-early stage of Himalayan Movement with fracture fillers including calcite and a small amount of clay and pyrite, the third type is near SN and NEE plane shear fractures and NW sectional shear fractures, formed in middle stage of Himalayan Movement-now with a low fracture filling degree and fracture fillers of small amount of calcite. The research results provide some theoretical references for further exploration and development.

Key words: shale, fracture, tectonic stages, tectonic evolution, Changning Anticline, Longmaxi Formation

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