国内外页岩气形成条件对比与有利区优选  

Comparison of the Formation Condition of Shale Gas between Domestic and Abroad and Favorable Areas Evaluation

作　　者：李昌伟[1] 陶士振[1] 董大忠[1] 管全中 

机构地区：[1]中国石油勘探开发研究院,北京100083

出　　处：《天然气地球科学》2015年第5期986-1000,共15页Natural Gas Geoscience

基　　金：国家科技重大专项"岩性地层油气藏成藏规律;关键技术及目标评价"(编号:2011ZX05001)资助

摘　　要：为了优选国内有利勘探区及层系,通过对美国、中国各个盆地富有机质页岩最新资料调研,将我国发育的富有机质页岩与美国现今技术可采储量居前的五大类页岩从区域构造背景、有机碳含量、储层物性、含气量等11个方面进行了对比分析。结果显示：①中国海相页岩有机质丰度、类型与美国海相页岩相当,皆以Ⅰ型或者Ⅱ1型为主,有机质成熟度要比美国页岩高,表明烃源岩可以并已经产生足够数量的烃类气体;陆相泥页岩TOC值低于北美地区页岩TOC值,有机质类型大都属于Ⅱ2型或者Ⅲ型,成熟度介于2%～4.5%之间且变化范围较大,生成页岩气潜力不如海相页岩好。②中国海相页岩脆性矿物含量比北美页岩高,黏土矿物含量相当,利于后期压裂改造;陆相页岩脆性矿物含量比北美地区低,黏土矿物含量与北美地区相当,不利于后期压裂改造。③中国海相页岩总体上孔隙度大小与北美海相页岩相当,但孔隙度分布范围比北美页岩大,孔隙类型与北美相当,显示出较好的储集性能;陆相页岩孔隙度大小要略低于北美海相页岩,孔隙类型与北美相当,储集性能较差。④中国海相页岩层埋藏深度主体分布在1 200～5 300m之间,比北美地区现今勘探的主体深度（1 300～4 000m）范围要大,并且由于构造演化复杂而与美国相对稳定的构造背景差异较大,导致我国页岩气保存条件变差和勘探风险增大;中新生界陆相页岩具有累计厚度大,单层厚度要小且平面展布范围小,虽然埋藏深度与北美地区相当,但由于后期构造运动破坏较大,因此对页岩气的保存十分不利。据此提出了适合我国海相页岩和陆相页岩的评价标准,并对各盆地优选出的有利地区和有利层位进行优选评价,指出海相页岩气勘探最有利的地区和层系为重庆周缘O3w—S1l、威远地区∈1q和S1l,陆相页岩气最有利地区和层系为鄂尔多斯盆In order to optimize the favorable area and strata of shale gas,we investigate the latest literature about organic-rich shale in basins of America and China.According to the comparison and analysis of the regional tectonic background,organic carbon content,sedimentary environment,organic carbon content,reservoir property,gas content and so on of the shale between North America and China,the following results have been reached：（1）Both China marine shale and America shale have similar organic matter abundance and types（typeⅠor typeⅡ1）.The thermal maturities of China′s marine shale are higher than America′s,which indicate that China′s marine shale have already generated adequate hydrocarbon;TOC（total organic carbon）of terrestrial shale is lower than that of America′s.Their organic type belongs to typeⅡ2or typeⅢ and maturity varies from 2% to 4.5%.Those indicate that the potential to generate hydrocarbon of terrestrial shale is lower than that of marine shale.（2）With similar content of clay mineral,China′s marine shale contains more brittle mineral,which is conductive to fracturing;In contrast,terrestrial shale contains less brittle mineral than that of America′s.（3）With similar pore types and porosity,China′s marine shale shows as good quality of reservoir as America′s.But terrestrial shale shows relatively lower porosity compared with the marine shale of America′s.（4）Burial depth of china′s marine shale distributes from 1 200 m to 5 300 m,which is wider than that of America′s（1 300-4 000m）.Meanwhile,due to the much more complicated tectonic evolution than the stable geotectonic background of America′s shale,those factors result in poor preservation condition of China′s marine shale and terrestrial shale.Therefore we propose an evaluation criterion of shale gas that suits for the marine/terrestrial shale in China according to the result of comparison and the exploration practice.An evaluation of favorable area and strata is carried out on the base of th

关 键 词：页岩气 海相页岩 陆相页岩 形成条件对比 有利区 

分 类 号：TE132.2[石油与天然气工程—油气勘探]