川东南地区五峰组—龙马溪组页岩现场解吸气特征及其意义  

Characteristics and significance of onsite gas desorption from Wufeng-Longmaxi shales in southeastern Sichuan Basin

作　　者：杨振恒[1,2,3,4] 魏志红[5] 何文斌[6] 范明[1,2,3,4] 俞凌杰[1,2,3,4] 徐二社[1,2,3,4] 钱门辉[1,2,3,4] 

机构地区：[1]中国石化石油勘探开发研究院无锡石油地质研究所,江苏无锡214126 [2]中国石化油气成藏重点实验室,江苏无锡214126 [3]页岩油气富集机理与有效开发国家重点实验室,江苏无锡214126 [4]国家能源页岩油研发中心,江苏无锡214126 [5]中国石油化工股份有限公司勘探分公司,四川成都610041 [6]中国石化重庆涪陵页岩气勘探开发有限公司,重庆408014

出　　处：《天然气地球科学》2017年第1期156-163,共8页Natural Gas Geoscience

基　　金：国家科技重大专项(编号:2015ZX05061001-001)资助

摘　　要：川东南地区上奥陶统五峰组—下志留统龙马溪组页岩为我国页岩气勘探开发的重要层位,在焦石坝、彭水、丁山、南川等地区都有重要发现。利用中国石化无锡石油地质研究所自主研发的快速现场解吸仪,对该地区典型页岩气井解吸气量、损失气量、总含气量、解吸气天然气组分和解吸气甲烷碳同位素(约30min取1样)进行测试。数据分析表明,上述数据对页岩气成藏机理、勘探开发有着重要的意义,主要表现在:1首样甲烷碳同位素值及特征可以预测页岩气富集层,为页岩气甜点层识别的有效方法;2总含气量和解吸天然气组分识别页岩气甜点层,为页岩气甜点层识别的最直接方法;3页岩气组分和碳同位素值联合判别页岩气成因类型,干酪根碳同位素特征和页岩气碳同位素特征可作为气源对比的有效手段;4页岩气组分特征可以判别该地区的保存条件,其对页岩气的散失程度研究具有指示意义;5损失气量和解吸气量及其关系能够反映出主要赋存方式的差异,对页岩气井不同阶段产气特征具有预测作用;6甲烷碳同位素值随解吸时间出现明显分馏效应,可以预测页岩气产气阶段及剩余气的含量。The Uppermost Ordovician-Lower Silurian Wufeng-Longmaxi Formations in southeastern Si- chuan Basin is the most important shale gas habitat in China, with a series of discoveries in Jiaoshiba, Peng- shui,Dingshan and Nanchuan areas.In this paper,we present data obtained using a selbdesigned apparatus of onsite shale gas desorption for measuring the gas content, chemical and stable carbon isotope composi- tion at 30 min interval,and discuss the implications of these data for shale gas accumulation and explora- tion.Carbon isotope value of the initial desorption gas of each shale sample proves valuable for sweet spot i- dentification.The total content and composition of desorption gas provides vital information for estimating the total gas resource in place.Combination of shale gas composition and carbon isotope value could be used to distinguish gas genetic type and relationship to source kerogen.A semi-quantitative model is presented to use the onsite gas desorption data in the assessment of shale gas preservation conditions related to regional structural evolution,as well as the prediction of general trend as a function of production time.

关 键 词：页岩气 川东南地区 连续性油气聚集 现场解吸 含气量 碳同位素分馏 

分 类 号：TE132.2[石油与天然气工程—油气勘探]