泸州—渝西地区志留系龙马溪组沉积期古地貌特征及控储作用  

Paleogeomorphological characteristics and reservoir control of the sedimentary period of Silurian Longmaxi Formation in Luzhou-Yuxi area

作　　者：刘勇[1] 刘永旸 赵圣贤 尹美璇 李博 陈雷[4] 吴帅材 谢圣阳 LIU Yong;LIU Yongyang;ZHAO Shengxian;YIN Meixuan;LI Bo;CHEN Lei;WU Shuaicai;XIE Shengyang(Gas Field Development Management Department,PetroChina Southwest Oil&Gasfield Company,Chengdu 610051,China;Shale Gas Research Institute of PetroChina Southwest Oil&Gasfield Company,Chengdu 610051,China;Sichuan Key Laboratory of Shale Gas Evaluation and Exploitation,Chengdu 610213,China;School of Southwest Petroleum University,Chengdu 610500,China)

机构地区：[1]中国石油西南油气田公司气田开发管理部,成都610051 [2]中国石油西南油气田公司页岩气研究院,成都610051 [3]页岩气评价与开采四川省重点实验室,成都610213 [4]西南石油大学地球科学与技术学院,成都610500

出　　处：《岩性油气藏》2025年第2期49-59,共11页Lithologic Reservoirs

基　　金：国家自然科学基金项目“沉积期水下地貌对海相优质页岩发育的差异控制作用”(编号:42372173);中国石油攻关性应用性科技专项“页岩气规模增储上产与勘探开发技术研究”(编号:2023ZZ21)联合资助。

摘　　要：泸州—渝西地区志留系龙马溪组页岩为中国非常规油气资源勘探的重点区块之一。通过全岩X射线衍射分析、岩矿鉴定、地震资料解释及钻井资料研究,运用印模法重建了研究区的沉积古地貌,并探讨其对优质页岩储层分布的影响机制。研究结果表明:①泸州—渝西地区志留系龙马溪组页岩沉积时期,泸州—渝西地区为“一隆起、一洼陷、两缓坡”的古地貌格局,沉积区可划分为水下隆起区、水下斜坡带和水下低洼区。②页岩的矿物组成以硅质矿物为主,黏土矿物、碳酸盐矿物及黄铁矿次之。可识别出10种页岩岩相类型,主要发育硅质页岩相组合(S)和混合质页岩相组合(M),其中硅质页岩相组合(S)在水下隆起区更为发育,且纵向上更具连续性,是优质岩相组合。③不同地貌单元的页岩岩相的发育程度及储层参数(TOC、孔隙度、含气量)存在明显差异,水下隆起区页岩TOC值为3.03%~5.06%,平均值为4.25%;孔隙度为4.81%~6.30%,平均值为5.46%;含气量为1.70%~7.62%,平均值为5.05%,其页岩储层品质优于水下斜坡带和水下低洼区。平面上,优质页岩具有高TOC、高孔隙度和高含气量的特征,呈带状分布于水下隆起区及其周缘。The Silurian Longmaxi Formation shales in Luzhou-Yuxi area is one of the key blocks for unconven50 tional oil and gas resource exploration in China.Based on whole rock X-ray diffraction analysis,rock mineral identification,seismic data interpretation and drilling data research,the sedimentary paleogeomorphology of the study area was reconstructed using the impression method,and its influence on the distribution of high-quality shale reservoirs was analyzed.The results show that:(1)During the deposition of Silurian Longmaxi Formation shale,the Luzhou-Yuxi area exhibited a paleogeomorphological pattern characterized by“one uplift,one depression,and two gentle slopes”.The sedimentary area can be subdivided into underwater uplift zones,underwater slope belts and underwater depression areas.(2)The mineral composition of shale is mainly composed of siliceous minerals,followed by clay minerals,carbonate minerals and pyrite.Ten types of shale lithofacies can be identified,mainly consisting of siliceous shale facies association(S)and mixed shale facies association(M).With the siliceous shale facies association(S)being more prevalent and continuous in the underwater uplift zones,make it the high-quality lithofacies in the area.(3)Significant differences in the development of shale lithofacies and reservoir parameters(TOC,porosity and gas content)were observed across different geomorphic units.In the underwater uplift zones,the TOC value of the shale ranges from 3.03% to 5.06%,with an average of 4.25%;the porosity ranges from 4.81% to 6.30%,with an average of 5.46%;and gas content ranges from 1.70% to 7.62%,with an average of 5.05%.The shale reservoir quality in this zone is significantly superior to that of underwater slope belts and underwater depression areas.Horizontally,high-quality shales,characterized by high TOC,high porosity and high gas content,are distributed in a banded pattern across the underwater uplift zone and its periphery.

关 键 词：印模法 硅质页岩岩相 储层品质 水下隆起区 水下斜坡带 水下低洼区 沉积古地貌 龙马溪组 志留系 泸州—渝西地区 

分 类 号：TE121[石油与天然气工程—油气勘探] P631.8[天文地球—地质矿产勘探]