川西坳陷异常高压形成机理与天然气分布关系研究  

FORMATION MECHANISM OF ABNORMAL FORMATION PRESSURES IN WEST SICHUAN DEPRESSION AND ITS RELATION TO THE DISTRIBUTION OF NATURAL GAS

作　　者：汪时成[1] 张金川[2] 贾庆素[3] 

机构地区：[1]北京石油大学 [2]北京中国地质大学 [3]中石化勘探开发研究院

出　　处：《天然气工业》2004年第3期5-8,共4页Natural Gas Industry

基　　金：国家自然科学基金 ( 4 0 172 0 5 2;4 0 2 72 0 6 2 )项目资助

摘　　要：对川西坳陷异常地层压力的研究一直存在不同观点 ,本文认为 ,高异常地层压力的形成机理具有 3种基本类型 ,即单相流的异常地层压力 (时间变化的函数 )、常规圈闭条件下两相流的异常地层压力 (与时间变化无关但其分布具有局限性 )以及致密储层条件下两相流的异常地层压力 (与时间因素无关且表现为区域性特点 )。川西坳陷三叠系和侏罗系地层严重致密化 ,生烃过程对地层增压作用具有重要影响 ,现今异常地层压力的形成主要取决于流体在储层孔隙中的流动方式以及由此所产生的能量交换 ,取决于致密储层条件对已形成高异常地层压力的封闭保存过程 ,因此川西坳陷现今异常地层压力的形成在原始动力类型上具有多因素复合性 ,研究表明 ,异常地层压力分布与天然气聚集之间具有复杂关系 。There exist always different viewpoints on the formation mechanism of abnormal formation pressures in West Sichuan Depression. Through analyzing it is considered in the paper that there are 3 kinds of basic patterns of forming high abnormal formation pressures there, i. e. the abnormal formation pressures of single-phase flowing (being a function of time variation) ; those of two-phase flowing under conventional trap conditions (being unrelated to time variation but having a limited distribution) ; and those of two-phase flowing under the conditions of tight reservoirs (being unrelated to time factor and expressed as regional distribution). A serious compactification has been found in the Triassic and Jurassic in West Sichuan Depression and the hydrocarbon-generating process played an important role in formation boost. At present, the formation of the abnormal formation pressures is mainly dependent on the flow patterns of the fluids in reservoir pore space and the energy exchange cause by these patterns, and on the influence of the tight reservoirs on the sealing and preservation process of the high abnormal formation pressures formed, so that the formation of current abnormal formation pressures in West Sichuan Depression is of multifactor complexity in the types of original dynamic forces. Through studying it was shown that the distribution of the abnormal formation pressures has a complicated relation to gas accumulation and the high abnormal formation pressures are the beneficial areas of enriching natural gas frequently.

关 键 词：异常地层压力 高压成因机理 天然气分布 川西坳陷 地层压力分布 

分 类 号：P618.13[天文地球—矿床学]