塔里木盆地塔中地区中下寒武统油气充注演化过程与勘探方向  

Hydrocarbon filling evolution and exploration direction of the middle-lower Cambrian interval in Tazhong area,Tarim Basin

作　　者：林潼[1] 王铜山[1] 李志生[1] 袁文芳[2] 马卫[1] 徐兆辉[1] 李秋芬[1] LIN Tong;WANG Tongshan;LI Zhisheng;YUAN Wenfang;MA Wei;XU Zhaohui;LI Qiufen(PetroChina Research Institute of Petroleum Exploration & Development, Beijing 100083, China;Research Institute of Exploration and Development of Tarim Oil Company of PetroChina, Korla 841000, China)

机构地区：[1]中国石油勘探开发研究院,北京100083 [2]中国石油塔里木油田分公司勘探开发研究院,新疆库尔勒841000

出　　处：《中国石油大学学报（自然科学版）》2021年第3期42-54,共13页Journal of China University of Petroleum(Edition of Natural Science)

基　　金：国家油气科技重大专项(2017ZX05008006-001);中国石油股份公司科技项目(2018A-0104)。

摘　　要：通过对塔中地区中下寒武统岩心开展铸体薄片、扫描电镜、背散射以及电子探针分析,明确中下寒武统发育四期的成岩矿物,并厘定各矿物与烃类的形成序次。在此基础上利用荧光分析、激光拉曼成份分析、均一温度测温等技术进行不同序次矿物中包裹体的分析。同时结合油气样品的同位素分析和生烃热模拟实验,揭示塔里木盆地中下寒武统油气的成藏演化过程,指出下步的有利勘探方向。结果表明寒武系盐下发生过连续的油气充注过程,烃类包裹体在均一温度、荧光颜色、包裹体类型上均表现出从低成熟到高—过成熟的特点,但主要以早期低成熟的液态烃充注为主;在成藏晚期部分低成熟度的液态发生烃裂解并形成少量天然气原地充注。综合分析认为塔中地区中下寒武统储层中充注的烃类主要来源于北部玉尔吐斯组烃源岩并通过断层运聚而来。运聚通道的顺畅与生排烃量决定了塔中构造圈闭中原油的充注饱和度,并与晚期液态烃裂解的程度共同控制了塔中地区寒武系盐下的油气成藏。Based on casting thin sections,scanning electron microscopy(SEM),backscattering and electron probe(EPA)analysis of cores of the middle and lower Cambrian in the Tazhong area,diagenetic minerals of the four stages of the middle and lower Cambrian have been identified,and the formation sequence of each mineral and hydrocarbon has been determined.On this basis,the inclusion analysis in minerals with different orders was carried out by fluorescence analysis,laser Raman component analysis,and uniform temperature measurement.At the same time,combined with the isotope analysis of oil and gas samples and hydrocarbon generation thermal simulation experiment,the accumulation and evolution processes of oil and gas in the middle and lower Cambrian in Tarim Basin are revealed,and the favorable exploration direction in the next step is pointed out.It was found that there was a continuous hydrocarbon charging process under the Cambrian salt.The hydrocarbon inclusions showed the characteristics of from low maturity to high-over maturity in the uniform temperature,fluorescence color and inclusion type,but mainly the early low-mature liquid hydrocarbon charging.In the late stage of hydrocarbon accumulation,some liquid with low maturity cracked and formed a small amount of natural gas in situ.Based on comprehensive analysis,it is believed that the hydrocarbon charged in the middle and lower Cambrian reservoirs in the Tazhong area mainly comes from the source rocks of the northern Yuertusi Formation and is transported through the faults.The migration smoothness of accumulation channels and hydrocarbon generation and expulsion together determine the crude oil filling saturation of the Tazhong structural trap,and jointly control the hydrocarbon accumulation under the Cambrian salt in the Tazhong area with the degree of late liquid hydrocarbon cracking.

关 键 词：塔里木盆地 寒武系盐下 成岩序次 包裹体 液态烃裂解 

分 类 号：TE122.3[石油与天然气工程—油气勘探]