不同类型页岩富集烃气能力模拟实验及微观结构特征研究  

Microstructure and Simulation Experiments of Extracted Gas Capability in Different Types of Shale

作　　者：王杰[1,2] 秦建中[1,2] 饶丹[1,2] 郑伦举[1,2] 李广友[1,2] 

机构地区：[1]中国石油化工集团公司油气成藏重点实验室,江苏无锡214151 [2]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214151

出　　处：《天然气地球科学》2013年第4期652-658,共7页Natural Gas Geoscience

基　　金：中国石化股份公司油田勘探开发事业部非常规先导项目;国家重点基础研究发展规划"973"项目(编号:2012CB214801)资助

摘　　要：基于前人对页岩气赋存形式和含气性影响因素的研究相对薄弱,结合页岩微观结构特征,利用地层孔隙热压模拟实验仪系统开展了不同类型页岩在不同成熟阶段、不同压力以及现今不同地质状态下的富集烃气能力模拟实验,研究发现页岩解析气产率的高低主要与其所经历的最高热演化程度密切相关,过成熟阶段页岩解析气产率较高。硅质页岩解析气所占的比例最高,钙质页岩次之,黏土质页岩最低。同一类型页岩成熟阶段解析气所占的比例最高,高成熟阶段次之,过成熟阶段最低,但解析气产率较高。超压的存在能显著提高页岩解析气产率,超压系数越大,解析气产率越高。在泥页岩热演化程度和演化历程相同的情况下,正常埋深页岩的解析气产率明显高于发生抬升的页岩;埋藏深度越深,页岩解析气产率越高。硅质页岩和钙质页岩脆性矿物含量高,大的孔隙和裂缝发育,孔隙度较高,解析气能力强,而黏土质页岩中脆性矿物含量相对较低,主要以有机质生烃过程形成的微孔隙为主,大的裂隙不发育,孔隙度相对较低,解析气能力肯定要低于硅质和钙质页岩。页岩残余气产率很低,基本上不具有工业开采价值,页岩含气量测定应以现场解吸气量和损失气量为主。综合研究认为页岩含气性主要受有机碳含量及储集物性共控,超压的存在是页岩气高产的关键,页岩气富集岩性为夹钙质(灰质)、硅质、砂质薄层(互层),页理发育的黑色、黑灰色泥页岩。Because of the previous researches on occurrences of shale gas and the influencing factors of gas-bearing property being insufficient, combined with shale microstructure characteristics, pyrolysis simulation experiments on enrichment capacity of hydrocarbon gas have been systematically carried out with different types of shale at different mature stages, under different lithostatic pressure and fluid pressure and with different geological characteristics. It indicates that the extracted gas amount in shale, being relatively large,is closely related to their thermal maturity,namely the extracted gas productivity is very large at o- ver-mature stage. The percentage of extracted gas with siliceous shale is the highest, calcareous shale is the second,while argillaceous shale is the lowest. For the same type of shale,the percentage of extracted gas is the highest at mature stage, which is intermediate at high-mature stage and the lowest at over-mature stage. Over pressure can obviously enhance the extracted gas productivity of shale. The bigger the over pressure coefficient, the higher the productivity of extracted gas. In the case of the same thermal maturity and evolution process of shale, the extracted gas production in the normal depth of shale is obviously higher than that in uplifted shale. The greater the burial depth, the higher the extracted gas yield of shale. Sili- ceous and calcareous shale possess high contents of brittle mineral, with big pore and fracture. Their porosi- ty is relatively big, so the extracted gas capability is strong. While argillaceous shale has relatively low con- tents of brittle mineral,mainly developing micropore during hydrocarbon generation process and there is no big fracture, resulting relatively small porosity. Therefore, the extracted gas capability is weaker than that of siliceous and calcareous shale. The residual gas yields of shale are very low, and basically it does not have industrial exploitation potential,so the amount of field desorbed and lost gas is key in shale gas

关 键 词：不同类型页岩 模拟实验 解析气 页岩气主控因素 微观结构 

分 类 号：TE132.2[石油与天然气工程—油气勘探]