【作者】 蒋珊； 董大忠； 王玉满； 吴伟； 李新景； 管全中；

【Author】 Jiang Shan;Wang Yuman;Wang Shuyan;Peng Ping;Dong Dazhong;Wu Wei;Li Xinjing;Guan;Quanzhong1Research Institute of Petroleum Exploration & Development,PetroChina;Exploration Division of Southwest Oil & Gas field Company,PetroChina;Exploration and Development Research Institute,PetroChina Southwest Oil & Gas field Company;National Energy Shale Gas R & D <Experimental> Centre;

【机构】 中国石油勘探开发研究院； 国家能源页岩气研发(实验)中心； 中国石油西南油气田勘探开发研究院；

【摘要】 有机质炭化研究是中国南方下寒武统页岩气勘探评价的重点工作之一。本文以四川盆地3口评价井为基础,利用电阻率测井响应和拉曼光谱分析法,对四川盆地中南部下寒武统页岩开展了有机质炭化表征,获得3点认识:(1)构造高部位页岩有机质拉曼光谱未出现G’峰,页岩电阻率测井曲线为正常扁平状特征,尚未发生有机质炭化作用;(2)早寒武世内裂陷区GS17井页岩电阻率测井曲线在5200m以浅为正常响应、5200m以深为低阻特征,且5200m以深页岩有机质样品拉曼光谱出现G’峰,Ro超过3.5%,显示5200m以深出现有机质炭化特征,但炭化程度较长宁地区弱;(3)威远—资阳地区有机质炭化深度门限变化大,一般介于4000～4600m;磨溪—高石梯地区有机质炭化深度界限较稳定,一般在5200m左右。由此预测,四川盆地下寒武统页岩主体为有机质炭化,仅乐山-龙女寺古隆起的威远—资阳、磨溪—高石梯等构造主体部位为非炭化区,该区筇竹寺组有较好页岩气勘探远景。更多还原

【Abstract】 The study of the graphitization of organic matter is the key work in the evaluation of shale gas exploration in the lower Cambrian in the south of China.Based on three evaluation wells of Sichuan basin,using the resistivity logging response and Raman spectrum analysis,the graphitization of organic matter in the lower Cambrian shale South-central Sichuan Basin was carried out.Three new conclusions were drawn:(1) There is no G ’peak in Raman spectra of shale in the structural high,and the resistivity of the organic-rich shale is normally flat features and organic matter is non-graphitized.(2) In the Cambrian aulacogen area(GS17 borefild),the resistivity logging curve of shale is normal response above 5200 m,whereas the resistivity is low under 5200 m.G ’peak can be observed in Raman spectra and Ro is over 3.5% in organic samples of shale under 5200 m,and these show that organic matter has been graphitized,but the degree of graphitization is weaker than Changning region.(3) The depth threshold of the graphitization of organic matter in Weiyuan-Ziyang area is diverse,which is generally range from 4000 m to 4600 m,while the depth threshold in the Moxi-Gaoshiti area is relatively stable,usually around 5200 m.It is speculated that the lower Cambrian shale in the main body of Sichuan basin is the graphitization area of organic matter,and only two non-graphitized areas appear in the sectonic main position of Weiyuan-Ziyang and Moxi-Gaoshiti in the Leshan-Longnüsi paleo-uplift,and the Qiongzhusi Formation in the area has better prospects for shale gas exploration.更多还原