滨浅湖相泥质烃源岩中不同赋存状态可溶有机质差异性研究  

Differences of solvable organic matters with different occurrence states in argillaceous source rocks of coastal shallow-lake facie

作　　者：杨燕[1,2,3] 雷天柱[1,2] 关宝文 田春桃[1,2,3] 吴应琴[1,2] 

机构地区：[1]甘肃省油气资源研究重点实验室,兰州730000 [2]中国科学院油气资源重点实验室,兰州730000 [3]中国科学院大学,北京100049

出　　处：《岩性油气藏》2015年第2期77-82,108,共7页Lithologic Reservoirs

基　　金：国家自然科学基金项目"不同赋存状态有机质的生烃特征和生烃贡献研究"(编号:41072107);"海相高-过成熟烃源岩成熟度判识新指标的研究"(编号:41272147)和"泥页岩中不同赋存态烃的分离和特征研究"(编号:41372130);国家油气重大专项"有机粘土复合体生排烃特征及规律研究"(编号:2011ZX05006-001)联合资助

摘　　要：通过对酒西盆地白垩系中沟组粉砂质泥岩的分步剥离,获取了滨浅湖相泥质烃源岩中不同赋存状态的可溶有机质,并比较了其地球化学特征的异同性。剥离出的3类可溶有机质分别是:在矿物表面附着的可溶有机质,即氯仿沥青"A";与碳酸盐牢固结合或被其包裹的可溶有机质,即氯仿沥青"C";与硅酸盐紧密结合的可溶有机质,即氯仿沥青"E"。研究发现这3类可溶有机质无论在含量上还是地球化学参数方面都存在明显不同。分析结果显示,氯仿沥青的含量为氯仿沥青"A">氯仿沥青"E">氯仿沥青"C",而总烃、饱和烃及正构烷烃的含量则是氯仿沥青"A">氯仿沥青"C">氯仿沥青"E"。OEP值、Pr/Ph值及∑C22-/∑C22+值分析显示,从氯仿沥青"A"到氯仿沥青"C"再到氯仿沥青"E",可溶有机质的成熟度逐渐增高。这些研究结果表明:在油气运移过程中,可溶有机质总是优先以物理吸附方式占据大孔隙,然后逐渐进入介孔和微孔;对于结构相似的有机分子,分子量越小,活性越强,相对更会富集在介孔和微孔中,使其中原油品质变好;碳酸盐矿物易富集非烃组分,硅酸盐矿物易富集非烃和沥青质等重质组分。上述研究结果将有助于烃源岩的精细评价和进一步的油气勘探。Through stripping silty mudstone of Cretaceous Zhonggou Formation of in Jiuxi Basin step by step, we obtained solvable organic matters with different occurrence states in argillaceous source rocks of coastal shallow-lake facies,and compared the similarities and differences of geochemical characteristics between them. Three kinds of solvable organic matters were stripped, including organic matters adhered on the surface of the minerals, namely chloroform asphalt ＂A＂, solvable organic matters combined solidly or parceled with carbonate, namely chloroform asphalt ＂C＂, and solvable organic matters integra ted with silicate closely, namely the chloroform asphalt ＂E＂, respectively. These three kinds of solvable organic matters were obviously different in terms of quantity and geochemical parameters. The analysis results show that chloroform asphalt ＂A＂ had the largest number, next is chloroform asphalt ＂E＂, and chloroform asphalt＂C＂ had the least number. However, both the total hydrocarbon and the saturated hydrocarbons and n-alkanes, t he number order from most to least was from the chloroform asphalt ＂A＂ to chloroform asphalt ＂C＂ to chloroform asphalt ＂E＂.OEP value, Pr/Ph ratio and ∑C22-/∑C22＋value show that the maturity of solvable organic matters was gradually increased from chloroform asphalt ＂A＂ to chloroform asphalt ＂C＂ to chloroform asphalt ＂E＂. These findings suggest that solvable organic matters always prefer to occupy large pore by physical adsorption, then gradually to the meso-porous and microporous in the process of oil and gas migration; and for similar structures of organic molecules, the smaller the weight of the molecular is, the stronger the activity will be and they will accumulate in meso-porous and microporous relatively,and finally makes the crude oil quality better. Carbonate minerals enriched in non-hydrocarbon compositions easily and the silicate minerals concentrate of the non-hydrocarbon easily and heavy constituents, such as asphaltenes

关 键 词：可溶有机质 不同赋存状态 地球化学特征 泥质烃源岩 

分 类 号：P593[天文地球—地球化学]