塔里木盆地库车北部坳陷深层煤层游离气含气饱和度计算  

Calculation of free gas saturation in deep coal seam of the northern Kuqa tectonic zone,Tarim Basin

作　　者：别康 崔瑞康 蔡天 信毅[1,2,3] 刘粤蛟 韩闯 孙建孟 BIE Kang;CUI Ruikang;CAI Tian;XIN Yi;LIU Yujiao;HAN Chuang;SUN Jianmeng(Tarim Oilfield Company,PetroChina,Korla,Xinjiang 841000,China;R&D Center for Ultra-Deep Complex Reservoir Exploration and Development,CNPC,Korla,Xinjiang 841000,China;Engineering Research Center for Ultra-deep Complex Reservoir Exploration and Development,Xinjiang Uygur Autonomous Region,Korla,Xinjiang 841000,China;School of Geosciences,China University of Petroleum(East China),Qingdao,Shangdong 266000,China)

机构地区：[1]中国石油天然气股份有限公司塔里木油田公司,新疆库尔勒841000 [2]中国石油天然气集团有限公司超深层复杂油气藏勘探开发技术研发中心,新疆库尔勒841000 [3]新疆维吾尔自治区超深层复杂油气藏勘探开发工程研究中心,新疆库尔勒841000 [4]中国石油大学(华东)地球科学与技术学院,山东青岛266000

出　　处：《世界石油工业》2025年第2期37-44,共8页World Petroleum Industry

基　　金：国家自然科学基金项目“基于数字岩心的深部煤层气弹性和声学响应机理研究”(42474156);中国石油天然气股份有限公司塔里木油田公司科技项目“库车北部构造带侏罗系煤岩气测井解释评价方法研究”(T202424)。

摘　　要：为了攻克深层煤层气开发难题,实现对深层煤层游离气含气饱和度的精准评估,为储量预测与采排方案优化奠定坚实基础,研究聚焦于深层煤层气储层特性。以塔里木盆地库车北部构造带侏罗系克孜勒努尔组煤层气为具体研究对象,基于等温吸附与声波联测实验,剖析了不同赋存状态甲烷与声波衰减系数的内在关联。在此基础上,构建了基于阵列声波测井的深层煤层游离气含气饱和度计算方法。运用现场解吸气法间接计算目的层游离气含气饱和度,以此验证新构建方法的准确性。研究结果表明:在低孔隙压力阶段,吸附气与游离气共同作用于声波衰减系数,对其产生显著影响;而当进入高孔隙压力状态,煤岩吸附达到饱和,此时仅有游离气成为影响声波衰减系数的关键因素。基于阵列声波测井的计算方法能够高效、准确地计算目的层游离气含气饱和度,且可敏锐捕捉煤层非均质性导致的游离气饱和度变化。结论认为,该项研究成果为该区块深层煤层游离气含气饱和度计算提供了可靠且实用的新途径,有力推动深层煤层气勘探开发理论与技术进步,可以为后续大规模、高效率开发深层煤层气资源提供理论依据与技术支撑。Compared with the middle-shallow coalbed methane reservoir,the formation temperature and formation pressure of deep coalbed methane reservoir increase due to the increase of burial depth.The factors controlling the occurrence state of deep coalbed methane change from the positive effect of pressure to the negative effect of temperature,and the adsorbed gas reaches the saturated state and is transformed into free gas.Free gas saturation is an important parameter for reserve prediction and optimal design of production and discharge plan,and its accurate evaluation is of great significance for deep coalbed methane development.In this paper,the coal-bed methane of the Jurassic Kizilenur Formation in the northern Kuqa tectonic zone of Tarim Basin is studied.The relationship between methane in different occurrence states and attenuation coefficient of sound wave is studied by isothermal adsorption and acoustic wave test.A calculation method of free gas saturation in deep coal seam based on array acoustic logging is established.By calculating the free gas saturation of the target layer based on on-site desorption method,the accuracy of calculating the free gas saturation of deep coal seam based on array acoustic logging is verified.The results show that both adsorptive gas and free gas affect acoustic attenuation coefficients at low pore pressure.At high pore pressure,only free gas can affect the attenuation coefficient of sound wave due to the adsorption saturation in coal rock.The method of calculating free gas saturation in deep coal seam based on array acoustic logging can effectively calculate the free gas saturation of the target layer,and can effectively reflect the change of free gas saturation caused by the heterogeneity of coal seam.The results of this study provide an important reference for the calculation of deep free gas saturation in this block,and provide important theoretical support for the exploration and development of deep coalbed methane in the study area.

关 键 词：深层煤层气 游离气 含气饱和度 克孜勒努尔组 阵列声波测井 塔里木盆地 

分 类 号：TE132[石油与天然气工程—油气勘探]