准噶尔盆地南缘中低煤阶煤层气富集成藏规律  

Middle to low rank coalbed methane accumulation and reservoiring in the southern margin of Junggar Basin

作　　者：李勇[1] 曹代勇[1] 魏迎春[1] 王安民[1] 张强[1] 吴鹏[2] 

机构地区：[1]中国矿业大学地球科学与测绘工程学院,北京100083 [2]中联煤层气有限责任公司,北京100011

出　　处：《石油学报》2016年第12期1472-1482,共11页Acta Petrolei Sinica

基　　金：中国地质调查局地调项目(1211302108025-4);国家自然科学基金项目(No.41272175)资助

摘　　要：准噶尔盆地南缘（准南）中低煤阶煤层气资源丰富但勘探程度相对较低,气体富集和主控因素认识不足,制约了开发。基于对准南地区构造、沉积、水文、物性和含气量分布的精细解剖,总结了煤层气富集成藏规律。准南煤系主要发育在天山山前断褶带,EW向断层和背斜密集;煤系沉积以冲积扇和河流相为主,煤层层数多且与砂岩叠置发育;煤层倾角大（部分地区大于50°）,风氧化带深延（大于400~600 m）;构造切割作用明显,多个水文地质单元发育;煤岩孔径较大,孔隙连通性好。针对研究区＂深部低煤阶、急倾厚煤层、多层砂煤组、构造断煤区＂的特点,提出了符合东部阜康等地区＂急倾斜煤层自吸附-水力封堵型＂,中部构造密集区＂断冲褶皱带多煤层压力封闭型＂,和西部大埋深地区＂构造-岩性圈闭煤系多源气混合型＂富集成藏模式。在煤层气开发中应优选相对构造高点和缓倾斜,并考虑地表水与地下水的稳定过渡带。多层次模糊评价表明东部四工河—乌鲁木齐河区段的煤层气资源、储层和保存条件均相对有利,可优先开发。The southern Junggar basin（SJB）bears huge amount of middle-low rank coalbed methane,with relatively low exploration extent,and the lack of knowledge in gas accumulation and its main controlling factors restrict the development practice.Based on the tectonic,sedimentary,hydrogeology,reservoir physical characteristics and gas content distributions,the gas accumulation and reservoiring models have been summarized.The coal-bearing strata in SJB develop in the north of Tianshan Range,with extensively developed eastwest direction faults and anticlines;the coal-bearing strata were deposited in alluvial-fluvial facies,resulting in several layers of coal seams and sandstone-coal combinations;and the coal seam dip angle is as much as 50°,with the oxidation zone extends to 400-600 m.Based on the upon characteristics of＂deep burried low rank coals,steep and thick coal seams,coal-sandstone combinations,fault cutting coal zones＂in SJB,the model of＂self-adsorption and hydraulic sealing type of steep coal seam＂suiting for Fukang area in the east,＂multiple coal seam pressure closed type in fault and fold belts＂in the middle areas and the＂structural and lithological trapped gases of multiple sources in coal bearing strata＂in the deep buried areas in the west are proposed.The relatively high point of structures and gently inclined strata should be firstly considered during CBM development and also of the transition belts of ground water and underground waters.Futhur,based on multi-level fuzzy evaluation,the Sigong River to Urumqi River areas in the east bear with relatively better coalbed methane resources,reservoir characteristic and preserve conditions,where should be firstly considered for development.

关 键 词：准噶尔盆地南缘 低煤阶煤层气 深煤层 富集成藏 开发有利区 

分 类 号：TE132.2[石油与天然气工程—油气勘探]