鄂尔多斯盆地三叠系长7富有机质段岩石热膨胀系数随温度演化特征及启示  

Evolution characteristics of thermal expansion coefficient of rocks with temperature of Triassic Chang 7 organic-rich reservoir and its implications in Ordos Basin

作　　者：张岩 侯连华[1] 崔景伟[1,2] 罗霞 林森虎[1] 张紫芸[1] ZHANG Yan;HOU Lianhua;CUI Jingwei;LUO Xia;LIN Senhu;ZHANG Ziyun(PetroChina Research Institute of Petroleum Exploration and Development,Beijing 100083,China;Key Laboratory of Petroleum Reservoir,PetroChina,Beijing 100083,China)

机构地区：[1]中国石油勘探开发研究院,北京100083 [2]中国石油油气储层重点实验室,北京100083

出　　处：《岩性油气藏》2022年第4期32-41,共10页Lithologic Reservoirs

基　　金：国家重点基础研究发展计划“中国陆相致密油(页岩油)形成机理与富集规律”(编号:2014CB239001)资助。

摘　　要：页岩油地下原位转化技术的应用是实现中低成熟度页岩油规模开发利用的有效手段,加热过程中页岩的热膨胀研究对于井眼稳定性、加热器寿命以及盖层完整性等工程评价具有重要意义。选取鄂尔多斯盆地三叠系长7页岩段3口取心井的岩心,在常规镜下薄片观察、X射线衍射分析基础上,采用DIL402 SE型热膨胀仪获得25~600℃下泥质粉砂岩、泥岩和黑色页岩的热膨胀系数及其动态演化特征。研究结果表明:(1)鄂尔多斯盆地三叠系长7富有机质段不同岩性的热膨胀系数存在较大差异,并随有机碳含量(TOC)的升高而增大。当TOC值小于5%时,岩石热膨胀系数“近指数型”增大;当TOC值大于等于5%时,岩石热膨胀系数呈“四段式”复杂变化。(2)研究区富有机质页岩的热膨胀系数各向异性因子最大,垂直层理方向上是平行层理方向上的1.7~2.7倍。(3)富有机质页岩生烃强度大,能产生微裂缝并导致热膨胀复杂变化。In-situ conversion processing(ICP)of shale underground is an effective and feasible option to realize the size development and utilization of medium to low-mature shale oil. The study of thermal expansion of shale during heating is of great significance for the engineering evaluation of wellbore stability,heater life and cap rock integrity. The thermal expansion coefficients and dynamic evolution characteristics of muddy siltstone,mudstone and shale at 25-600 ℃ were obtained by using DIL402 SE instrument on the basis of thin section observation and X-ray diffraction analysis of cores from three wells of Triassic Chang 7 shale layer in Ordos Basin. The results show that:(1)The thermal expansion coefficients of rocks with different lithologies in the study area differ greatly and increase with the increase of organic carbon content. The thermal expansion coefficients of rocks with TOC being less than 5% increase almost exponentially,while the thermal expansion coefficients of rocks with TOC being greater than or equal to 5% show a“four stage”complex change.(2)The anisotropy factor of the thermal expansion coefficients of organic-rich shale in the study area is the largest,which is 1.7-2.7 times in vertical bedding direction than that in parallel bedding direction.(3)The high hydrocarbon generation intensity of organic-rich shale can cause microfractures and lead to complex changes in thermal expansion.

关 键 词：原位转化技术 富有机质页岩 热膨胀系数 各向异性因子 动态演化 长7页岩 三叠系 鄂尔多斯盆地 

分 类 号：TE1339[石油与天然气工程—油气勘探] P618.13[天文地球—矿床学]