鄂尔多斯盆地巴汗淖地区奥陶系马家沟组马五6段碳酸盐岩成岩作用地球化学特征  

Carbonate geochemical characteristics of the ordovician Ma5_6^(th) member of Majiagou Formation from Bahannao area,Ordos Basin

作　　者：田雯[1] 陈刚[1] 李文厚[1] 高路恒 章辉若 杨甫[4,5] 田斌 

机构地区：[1]西北大学地质系西北大学大陆动力学国家重点实验室,西安710069 [2]延长石油集团研究院,西安710069 [3]长庆油田分公司勘探部,西安710000 [4]国土资源部煤炭资源勘查与综合利用重点实验室,西安710016 [5]陕西省煤田地质有限公司,西安710016 [6]胜利油田渤海钻井二公司,东营257200

出　　处：《环境化学》2016年第1期199-207,共9页Environmental Chemistry

基　　金：国家科技重大专项(2008ZX05005-004-007HZ);中国地质调查局油气资源调查项目(1212011220761-03);大陆动力学国家重点实验室科技部专项经费重点课题(BJ14252)联合资助~~

摘　　要：巴汗淖地区马五6段是近年来鄂尔多斯盆地北部奥陶系海相油气勘探关注的新层段.采用ICP-AES离子体质谱地球化学测试与成岩演化相结合的研究方法,探讨分析了巴汗淖地区马五6段风化壳型碳酸盐岩储层的主要成岩作用类型.研究结果表明,研究区碳酸盐岩的SiO2、K2O、TiO2、P2O5、Mn、Na含量略低,Al2O3、Fe的含量高,Eu、Ce显负异常,说明研究区地层经历埋藏成岩作用,且后期地层抬升到地表遭受了大气淡水的淋滤;其中,白云岩的MgO值及Na的含量与灰岩的含量相比略高,这主要是埋藏白云石化作用的结果.进一步研究表明,埋藏溶解作用、埋藏白云石化作用以及表生期大气淡水淋滤作用使得次生孔隙发育,有利于油气的储集.In recent years,the Ordovician Ma5th6 member of Majiagou Formation from Bahannao area（ northern of Ordos Basin） has becomes a new stage of oil and gas exploration concern. This study combined ICP-AES ion mass spectrumetry geochemical test with diagenetic evolution,to investigate discuss the main diagenesis types of the weathering crust carbonate reservoir of Ma5th6 member inBahannao area. The contents of Si O2,K2 O,Ti O2,P2O5,Mn,Na from carbonate rocks were slightly lower but contents of Al2O3 and Fe were higher. The contents of Eu and Ce show negative anomaly.The geochemical characteristics indicate that strata from Bahannao area experienced burial diageneses and suffered atmospheric fresh water leaching during the subsequent late diagenesis dut to the region uplift. The Mg O and Na values of dolomite was higher than those of limestone as a result of buried dolomitization. Further study showed that burial dissolution, burial dolomitization and atmospheric fresh water leaching influenced the development of secondary pore which is advantageous to the oil and gas reservoir.

关 键 词：主量元素 微量元素 稀土元素 成岩作用 

分 类 号：P618.13[天文地球—矿床学] P584[天文地球—地质学]