石油与天然气地质 ›› 2020, Vol. 41 ›› Issue (3): 484-491,557.doi: 10.11743/ogg20200305

• 油气地质 • 上一篇    下一篇

四川盆地剑阁地区须家河组致密砾岩储层裂缝特征及对天然气产能的影响

吕文雅1,2, 苗凤彬2,3, 张本键4, 曾琪4, 徐翔2, 季敏5   

  1. 1. 油气资源与探测国家重点实验室 中国石油大学(北京), 北京 102249;
    2. 中国石油大学(北京)地球科学学院, 北京 102249;
    3. 中国地质调查局 武汉地质调查中心, 湖北 武汉 430205;
    4. 中国石油 西南油气田分公司 川西北气矿, 四川 江油 621709;
    5. 中国石化 石油勘探开发研究院, 北京 100083
  • 收稿日期:2019-05-25 修回日期:2020-03-26 发布日期:2020-06-16
  • 作者简介:吕文雅(1990-),女,博士、讲师,非常规油气田开发地质。E-mail:wylvwenwen@163.com。
  • 基金资助:
    国家科技重大专项(2016ZX05003-001,2017ZX05009001-002);中国石油大学(北京)青年拔尖人才科研启动基金项目(2462017YJRC057)。

Fracture characteristics and their influence on natural gas production: A case study of the tight conglomerate reservoir in the Upper Triassic Xujiahe Formation in Jian'ge area,Sichuan Basin

Lyu Wenya1,2, Miao Fengbin2,3, Zhang Benjian4, Zeng Qi4, Xu Xiang2, Ji Min5   

  1. 1. State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum(Beijing), Beijing 102249, China;
    2. College of Geosciences, China University of Petroleum(Beijing), Beijing 102249, China;
    3. Wuhan Center of China Geological Survey, Wuhan, Hubei 430205, China;
    4. Branch of Chuanxibei Gas Field, PetroChina Southwest Oil and Gas Field Company, Jiangyou, Sichuan 621709, China;
    5. Petroleum Exploration and Production Research Institute, SINOPEC, Beijing 100083, China
  • Received:2019-05-25 Revised:2020-03-26 Published:2020-06-16

摘要: 天然裂缝是致密砾岩储层重要的储集空间和主要的渗流通道,影响致密天然气的成藏、富集及单井产能。利用地表相似露头、岩心、薄片、测井和生产资料,在研究四川盆地剑阁地区须家河组致密砾岩储层天然裂缝类型和发育特征的基础上,分析并阐明了天然裂缝对天然气产能的影响。四川盆地剑阁地区须家河组致密砾岩储层发育穿砾缝、砾内缝和砾缘缝,从地质成因上,穿砾缝为构造裂缝,砾内缝包括构造、构造-成岩和母岩裂缝,砾缘缝为构造-成岩裂缝。其中穿砾缝的面密度、孔隙度和渗透率最大,其次为砾内缝,砾缘缝相对较小,穿砾缝对致密砾岩储层贡献更大,更有利于天然气富集高产。裂缝发育程度与产气量呈正相关,裂缝密度越大,产气量越高。在近东西(EW)向至NWW-SEE向现今地应力作用下,不同方向裂缝对天然气产能的贡献存在差异,其中近EW向裂缝地下开度相对较大,连通性好,对天然气产能贡献最大;其次为近NS和NW-SE向裂缝,NE-SW向裂缝对天然气产能的贡献较小。

关键词: 产能, 天然裂缝, 致密砾岩储层, 须家河组, 剑阁地区, 四川盆地

Abstract: Natural fractures are important storage space and main seepage channels in tight conglomerate reservoirs,which function to influence the accumulation,enrichment and single-well productivity of tight gas.An integration of analogous outcrop,core,thin section,well log and production data,is applied to the study on the types and characteristics of natural fractures in the tight conglomerate reservoir of the Upper Triassic Xujiahe Formation in Jian'ge area,Sichuan Basin,and then the influence analysis of natural fractures on tight gas productivity.Trans-gravel,intra-gravel and gravel-edge fractures are developed in the tight conglomerate reservoirs.In terms of geological origin,trans-gravel fractures are tectonic fractures; intra-gravel fractures include tectonic,tectonic-diagenetic and parent-rock fractures; and gravel-edge fractures are tectonic-diagenetic fractures.Among others,trans-gravel fractures are the largest in areal density,porosity and permeability,followed by intra-gravel fractures and gravel-edge ones.Thus,the trans-gravel fractures are more contributive to the formation of the tight conglomerate reservoirs,and the most conducive to natural gas enrichment with high yield.The degree of fracture development is positively correlated with gas production:the greater the fracture density is,the greater the tight gas productivity could be.Under the present-day in-situ stress trending towards the nearly east-west (EW) to NWW-SEE direction,the contributions made by fractures of diverse directions are differential on the tight gas productivity.The nearly EW-trending fractures feature bigger apertures and good connectivity,being the most favorable area for tight gas production,followed by nearly NS- and NW-SE-trending fractures,and then the NE-SW-trending ones.

Key words: productivity, natural fracture, tight conglomerate reservoir, Xujiahe Formation, Jian'ge area, Sichuan Basin

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