阿姆河盆地东北部碳酸盐岩区域性地层超压成因  

Regional overpressure genesis of carbonate formations in the northeastern Amu Darya Basin

作　　者：聂明龙 张波 程木伟[3] 于太极 Nie Minglong;Zhang Bo;Cheng Muwei;Yu Taiji(Safety Science and Engineering College,Liaoning Technical University,Huludao,Liaoning 125105;Key Laboratory of Mine Thermodynamic Disasters and Control of Ministry of Education,Huludao,Liaoning 125105;CNPC(Turkmenistan)Amu Darya River Gas Company,Beijing 100083)

机构地区：[1]辽宁工程技术大学安全科学与工程学院,辽宁葫芦岛125105 [2]矿山热动力灾害与防治教育部重点实验室,辽宁葫芦岛125105 [3]中国石油(土库曼斯坦)阿姆河天然气公司,北京100083

出　　处：《地质科学》2024年第4期1098-1110,共13页Chinese Journal of Geology(Scientia Geologica Sinica)

基　　金：中国石油天然气集团公司重大科技专项(编号:2023ZZ07⁃01);辽宁省教育厅基本科研项目(编号:JYTQN2023207)资助。

摘　　要：由于碳酸盐岩沉积成岩作用与碎屑岩不同,碳酸盐岩地层超压具有高度非均质性,然而阿姆河盆地东北部地区碳酸盐岩地层却发育了大面积区域性超压现象。本文运用实测地层压力和钻井液密度计算压力的方法,刻画了研究区碳酸盐岩地层异常超压的空间分布特征及其与上覆膏盐岩地层压力的垂向叠置关系,运用碳酸盐岩物性、压汞分析和烃源岩生烃模拟及构造挤压增压模拟等方法,从纵向与横向对比超压与常压差异分布的角度,探讨了碳酸盐岩超压成因。研究表明:盐下碳酸盐岩发育常压与强超压,强超压区大面积连续发育,与局部构造和断裂无关。盐下致密碳酸盐岩形成封闭体系,虽然构造挤压作用发育了断层与裂缝,但是由于膏盐岩的塑性,未破坏盐下碳酸盐岩封闭体系,是超压区域性连续发育的前提;同时,强烈构造挤压对超压发育有重要贡献。由于膏盐岩的良好封闭性,使膏盐岩层与碳酸盐岩层之间优质烃源岩(TOC最高达6%)生成液态烃类向盐下碳酸盐岩排烃,也促进了超压发育;由于膏盐岩与碳酸盐岩之间发育的泥岩隔层,石膏矿物脱水作用不是碳酸盐岩超压的成因,并且,石膏成岩脱水作用对盐下碳酸盐岩开放体系作用微弱。研究成果对盐下异常超压的预测具有借鉴意义。Carbonate rock sedimentary formations are different from clastic rock formations,possessing highly heterogeneous overpressure characteristics.Regional overpressure phenomena are evident in the carbonate formation in the northeastern part of the Amu Darya Basin,and in this study,the measured formation pressure and the formation pressure calculated from drilling fluid density are used to determine the spatial distributions of overpressure anomalies in different stratigraphic layers of carbonate rocks,as well as their vertical superposition relationships with the formation pressure of overlying gypsum-salt rocks.By using methods such as the physical properties of carbonate rock,mercury analysis,hydrocarbon source rock analysis,hydrocarbon generation simulation,and tectonic extrusion pressure simulation,the origin of overpressure in the carbonate rocks is investigated by comparing the differential distributions of both longitudinal and transverse overpressure and normal pressure.The results show that the sub-salt carbonate rocks developed with both normal pressure and strong overpressure.There is a strong,continuous overpressure zone that spans a large area and is unrelated to local structures and fractures.The sub-salt dense carbonate rocks form a closed system.Although tectonic extrusion has resulted in the development of faults and fractures,the plasticity of the salt rocks has prevented the destruction of the sub-salt carbonate rock closed system,facilitating the continuous development of the overpressure area.Strong tectonic extrusion has also made a significant contribution to the development of overpressure.Due to the good closure of the gypsum-salt rocks,high-quality hydrocarbon source rocks(with TOC up to 6%)between the gypsum-salt rock layer and the carbonate rock layer generate liquid hydrocarbons,which are expulsed into the sub-salt carbonate rock,further promoting the development of overpressure.Dehydration of the gypsum minerals between the gypsum-salt rocks and the carbonate rocks is not the cause of c

关 键 词：碳酸盐岩地层 区域性异常高压 盐下 前陆冲断带 阿姆河盆地 

分 类 号：TE122[石油与天然气工程—油气勘探]