四川盆地茅口组滩相孔隙型白云岩储层天然气勘探的突破及启示——以川中北部地区JT1井天然气立体勘探为例  

Breakthrough of natural gas exploration in the beach facies porous dolomite reservoir of Middle Permian Maokou Formation in the Sichuan Basin and its enlightenment:A case study of the tridimensional exploration of Well JT1 in the central-northern Sichuan Basin

作　　者：杨雨[1] 谢继容[2] 赵路子[1] 黄平辉[3] 张玺华[2] 陈聪[2] 张本健[2] 文龙[4] 汪华[2] 高兆龙 山述娇[2] YANG Yu;XIE Jirong;ZHAO Luzi;HUANG Pinghui;ZHANG Xihua;CHEN Cong;ZHANG Benjiang;WEN Long;WANG Hua;GAO Zhaolong;SHAN Shujiao(PetroChina Southwest Oil&Gasfield Company,Chengdu,Sichuan 610051,China;Exploration and Development Research Institute,PetroChina Southwest Oil&Gasfield Company,Chengdu,Sichuan 610041,China;Exploration Department,PetroChina Southwest Oil&Gasfield Company,Chengdu,Sichuan 610051,China;Northwest Sichuan Division,PetroChina Southwest Oil&Gasfield Company,Jiangyou,Sichuan 621741,China)

机构地区：[1]中国石油西南油气田公司 [2]中国石油西南油气田公司勘探开发研究院 [3]中国石油西南油气田公司勘探事业部 [4]中国石油西南油气田公司川西北气矿

出　　处：《天然气工业》2021年第2期1-9,共9页Natural Gas Industry

基　　金：国家科技重大专项“四川盆地二叠系—中三叠统大型气田富集规律与目标评价”(编号:2016ZX05007004);中国石油天然气股份有限公司重大科技专项“西南油气田天然气上产300亿立方米关键技术研究与应用”(编号:2016E-06)。

摘　　要：四川盆地中二叠统茅口组浅海碳酸盐岩储层以往一直被认为是裂缝、缝洞型储层,近期风险探井——JT1井继在川中北部太和含气区下寒武统沧浪铺组获得天然气勘探突破以后,又在其上的茅口组发现了滩相孔隙型白云岩储层且测试获得112.8×10^(4)m^(3)/d的高产工业气流,JT1井实现了纵向上多套含气层系天然气立体勘探的突破和茅口组储层类型的新发现。为了进一步明确太和含气区茅口组滩相孔隙型白云岩储层的特征及控制因素,对其沉积演化、高能滩相特征、储层特征及下一步天然气勘探方向等进行了研究。研究结果表明:①川中北部台洼边缘发育茅二段滩相孔隙型储层,岩性主要为残余砂屑云岩和亮晶砂屑灰岩,储集空间主要为粒间孔和晶间孔,平均孔隙度为4.9%;②茅口组沉积中晚期川北地区发育广元—巴中古裂陷,川中北部发育台内洼地,川中—川北地区茅口组高能滩围绕裂陷和台洼边缘规模分布,呈现“一缘三高带”的古地理格局;③受高能滩相的控制,川中北部茅口组孔隙型储层沿“一缘三高带”规模分布,“一缘三高带”高能滩相分布面积近6000 km^(2),该区垂向上发育寒武系、志留系、二叠系等多套烃源岩且烃源断裂发育、疏导体系良好,有利于油气规模富集成藏。结论认为,四川盆地茅口组具有相控孔隙型储层发育的有利地质条件,“一缘三高带”是滩相孔隙型白云岩储层天然气勘探的有利区;该认识为四川盆地天然气规模增储指明了新的勘探领域和方向。The neritic carbonate reservoir of Middle Permian Maokou Formation in the Sichuan Basin has been always treated as a fractured and fractured-vuggy reservoir.After realizing the breakthrough of natural gas exploration in the Lower Cambrian Canglangpu Formation in the Taihe gas bearing area of central-northern Sichuan Basin,Well JT1,a wildcat well,recently discovers a beach facies porous dolomite reservoir in the Maokou Formation above the Canglangpu Formation,and the high-yield industrial gas flow of 112.8×10^(4)m^(3)/d is obtained during the test.And thus,Well JT1 achieves the breakthrough of tridimensional natural gas exploration in multiple gas bearing series of strata in the vertical direction and realizes the new discovery of reservoir type in the Maokou Formation.In order to further clarify the characteristics and control factors of the beach facies porous dolomite reservoir of Maokou Formation in the Taihe gas bearing area,this paper studied its sedimentary evolution,high-energy beach facies characteristics,reservoir characteristics and following natural gas exploration direction.And the following research results were obtained.First,along the syneclise margin of central-northern Sichuan Basin develops a beach facies porous reservoir of the second Member of Maokou Formation,whose lithology is dominated by residual dolarenite and calcsparite calcarenite and reservoir space is mainly acted by intergranular pores and intercrystalline pores,with the average porosity of 4.9%.Second,in the middle and late stage of Maokou period,Guangyuan-Bazhong paleo faulted depression was developed in the northern Sichuan Basin and intraplatform low was developed in the central-northern Sichuan Basin.In the central and the northern Sichuan Basin,the high-energy beach of Maokou Formation is distributed around the faulted depression and the syneclise margin in a large scale,and the paleogeographic pattern of"one-margin and three-high belt"is presented.Third,under the control of high-energy beach facies,the Maokou Formation porou

关 键 词：四川盆地 川中北部地区 太和含气区 中二叠统茅口组 滩相孔隙型白云岩储集层 天然气立体勘探 新领域新方向 

分 类 号：P618.13[天文地球—矿床学]