收稿日期: 2009-02-21
修回日期: 2009-09-25
网络出版日期: 2010-02-10
基金资助
国家科技重大专项项目“四川、塔里木等盆地及邻区海相碳酸盐岩大油气田形成条件、关键技术及目标评价”(编号:1K-002)资助.
Differential Hydrocarbon Migration and Accumulation in Complex Fissure and Pore Carbonate Reservoir of Superposition Basin:An Example of Pore-Fissure-Fracture Reservoir Formed by Supergene Karstification in Tz83 Well Area
Received date: 2009-02-21
Revised date: 2009-09-25
Online published: 2010-02-10
叠合盆地海相碳酸盐岩介质油气运聚机理是叠合盆地油气勘探必须解决的关键问题之一。塔中83井区原油和天然气产量在NE向断层与NW向断层的交会部位异常高,而随着远离断层交会部位逐渐降低,并沿构造脊展布,这一点违背传统的背斜核部富气而翼部富油的模式。基于碳酸盐岩表生岩溶的相关研究成果,建立了表生岩溶缝洞体系的基本模型。在分析油气在表生岩溶缝洞体系运聚过程的基础上,认为复杂缝洞体系中油气的差异运聚原理是产生这种现象的关键。油气在表生岩溶缝洞体系中运移时,总是要先将临近油气充注点的孔隙或缝洞充满至其溢出点后,才能继续向远处运移,并沿油气运移路径顺次充满远处的孔洞缝体系,导致:①近油气注入点富气,而远油气注入点富油;②油水关系复杂并受侧向联通通道的控制,这种模式与塔中油气的分布规律非常吻合。基于此,认为研究区断层的交会部位是油气的注入点,油气运移的主输导通道沿构造脊展布。岩溶缝洞体系差异运聚模式提示:①对缝洞体系的油气勘探应首先刻画缝洞体系的结构,在分析油气注入点和主输导通道的基础上才能对油水关系进行很好的预测;②应坚定油气注入点和主输导通道附近圈闭的勘探,不要因局部圈闭的失利而否认整个勘探区带。
王福焕, 韩剑发, 向才富, 于红枫, 张云峰, 王霞 . 叠合盆地碳酸盐岩复杂缝洞储层的油气差异运聚作用——塔中83井区表生岩溶缝洞体系实例解剖[J]. 天然气地球科学, 2010 , 21(1) : 33 -41 . DOI: 10.11764/j.issn.1672-1926.2010.01.33
Mechanism of hydrocarbon migration and accumulation in complicated carbonate pore\|fissure\|fracture reservoir of the superposition basin is a key scientific problem to be solved. The production of crude oil and natural gas in the Tz83 well area is much high at the intersection point between NE and NW trending faults, gradually decreases away the intersection point and distributes along the structural ridge. This phenomenon is contradiction with the traditional distribution model of gas accumulated in the core while oil accumulated in the limb of an anticline. A conceptual model of the pore-fissure-fractures reservoir formed by supergene karstification was built according to the related carbonate karstification research results. The differential hydrocarbon migration and accumulation in the complex fissure-pore carbonate reservoir is the fate factor causing the abnormal distribution of oil and gas. Hydrocarbon was firstly charged into the nearest hole, pore and fissure; then migrated and charged into the other compartment alone migration pathway after the first compartment filling. Thus hydrocarbon was charged into the compartment in order, with two patterns as follows: ① Preferential accumulation of gas at the hydrocarbon-filling point, while oil accumulation far away the filling point; ② Complex gas-oil-water correlation controlled by the lateral connected networks. The latter pattern of hydrocarbon migration and filling is in coincidence with the oil and gas distribution in Tazhong area. Therefore, the intersection position of the faults is a place of oil and gas filling, and the main pathway of oil and gas migration is along structural ridge. The differential hydrocarbon migration and accumulation in the complex fissure-pore carbonate reservoir give us the following indications: ①Hydrocarbon exploration of fissure and pore reservoir should firstly describe the structure of the fissure-fracture reservoir, and the special distribution of gas-oil-water correlation can be predicted according to main charging point and migration pathway; ②Hydrocarbon exploration should be confined to hydrocarbon charging point and main migration pathway. The exploration aim should not be given up due to some failed wells.
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