摘要
四川盆地中三叠统雷口坡组天然气资源丰富,是后期天然气重要的战略准备层系。XT1井雷四3亚段测试获气是中国石油天然气股份有限公司在川西南部雷口坡组勘探的又一重要突破。为扩大川西南部大兴场地区雷四3亚段勘探成果,进一步明确储层特征及控制因素,利用岩心、薄片及分析化验资料对雷四3亚段储层岩石类型、储集空间、物性及储层发育控制因素进行综合研究。研究结果表明:①川西南部大兴场地区雷四3亚段储集岩主要为颗粒白云岩,其次为细(粉)晶白云岩;储集空间以孔隙为主,伴有少量溶洞和裂缝,物性总体表现为“低孔低渗”的特征。②从分布特征上来看,储层纵向叠置,厚度薄,横向储层连片展布,由北西向南东方向逐渐减薄直至尖灭。③有利相带控制了优质储层的展布,为储层发育提供岩性基础;表生岩溶作用是形成储层有效储集空间的最直接手段;构造作用产生的裂缝改善了储层的储集性能。
There are abundant natural-gas resources in the Middle Triassic Leikoupo Formation,Sichuan Basin,which is an important strategic formation prepared for the later stage.Some gas produced from T2l3^4 submember of XT1 well is PetroChina’s another important exploration breakthrough in the Leikoupo Formation,southwestern Sichuan Basin.In order to expand some exploration achievements in this submember of Daxingchang area in southwestern Sichuan Basin and further clarify both characteristics and control factors of T2l3^4 reservoirs,a comprehensive study on their rock type,reservoir space,petrophysical properties,and control factors was carried out by means of core analysis,thin-section identification,and test data.Results show that(1)the T2l3^4 reservoirs in Daxingchang area are dominated by grain dolomite and secondarily by fine(powder)crystalline dolomite.The reservoir space includes mainly by pores with a small number of vugs and fractures.And they are overall characterized by low porosity and permeability;(2)speaking of distribution characteristics,the reservoirs are vertically stacked with small thickness,laterally continuous,and gradually thinning from northwest to southeast until pinching out;and(3)favorable facies zone controls the distribution of high-quality reservoirs and provides lithologic base for reservoir development.Furthermore,supergene karstification is the most direct means to form effective reservoir space,and fractured-induced tectonism may improve reservoir performance.
作者
林怡
徐诗雨
余良志
何开来
杨京
曾乙洋
黎洋
赵春妮
Lin Yi;Xu Shiyu;Yu Liangzhi;He Kailai;Yang Jing;Zeng Yiyang;Li Yang;Zhao Chunni(Exploration and Development Research Institute,PetroChina Southwest Oil&Gasfield Company,Chengdu,Sichuan 610041,China;Exploration Division,PetroChina Southwest Oil&Gasfield Company,Chengdu,Sichuan 610041,China)
出处
《天然气勘探与开发》
2020年第3期8-18,共11页
Natural Gas Exploration and Development
基金
“十三五”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)。
关键词
川西南部
大兴场地区
中三叠世
雷口坡组
储层特征
颗粒白云岩
储层主控因素
Southwestern Sichuan Basin
Daxingchang area
Middle Triassic
Leikoupo Formation
Reservoir characteristics
Grain dolomite
Main factor affecting reservoir
