川东北地区毛坝气藏流体包裹体研究及其地质意义

发布时间：2018-01-06 17:20

  本文关键词：川东北地区毛坝气藏流体包裹体研究及其地质意义　出处：《成都理工大学》2016年硕士论文　论文类型：学位论文

  更多相关文章： 毛坝气藏 流体包裹体 物理化学条件 油气充注 成藏过程 川东北

【摘要】：毛坝气藏是一个位于下三叠统飞仙关组碳酸盐岩储集层中的中型气藏。本文通过对川东北毛坝气藏下三叠统飞仙关组储层开展系统的流体包裹体研究,计算并分析毛坝气藏的成藏物理化学条件,划分油气充注期次,确定成藏时代,并且探讨储层油气演化和成藏模式。研究结果表明:毛坝气藏中包裹体赋存于下三叠统飞仙关组碳酸盐溶孔、溶洞中充填的方解石和石膏中。研究区内包裹体类型可分为H2O包裹体、烃-H2O包裹体、烃包裹体三大类。毛坝气藏储层流体包裹体组合划分为四期:第一期(I)包裹体形成于早成岩期,以液相H2O包裹体和气液H2O包裹体为主,气液H2O包裹体均一温度范围在85~89℃之间;第二期(II)包裹体形成于晚成岩期早阶段,主要为液相H2O包裹体和气液H2O包裹体,液相烃包裹体和气液烃包裹体,气液H2O包裹体均一温度变化范围为113~150℃;第三期(III)包裹体形成于晚成岩期晚阶段,以H2O包裹体、气相烃包裹体、烃-H2O包裹体为主,气液H2O包裹体均一温度范围在155~206℃之间;第四期(IV)包裹体形成于成岩末期,包裹体组合有液相H2O包裹体、气液H2O包裹体、含自然硫气液水包裹体、气相烃包裹体等,气液H2O包裹体其均一温度为100~152℃。储层流体的盐度(wt%NaCl)变化范围为0.35~17.29%(wt%NaCl),储层流体的密度0.91~1.08g/cm3,从II期到IV期,流体的盐度、密度逐渐降低;毛坝气藏压力变化范围为1843~2025×105Pa,其埋藏深度在7091~7791m之间。单个流体包裹体成分分析表明,毛坝气藏中CH4包裹体和烃-H2O包裹体的气相成分主要为CH4,其次含有部分H2S气体、少量的CO2和C6H6等,在毛坝地区飞仙关组鲕滩气藏储层中还发现了一种含自然硫的气液水包裹体。毛坝气藏一共经历了两次油气充注:第一期油气充注为早侏罗世晚期至中侏罗世(178~164Ma),第二次油气充注时为晚侏罗世至始新世(154~55Ma)。始新世以后,该气藏进入到了后生改造破坏演化阶段。根据毛坝气藏储层流体包裹体的期次、组合和均一温度,表明毛坝气藏油气经历了开始生油阶段,石油大量生成和凝析-湿气阶段,干气阶段,后生改造破坏阶段四个阶段。毛坝气藏成藏过程大致经历了三个阶段:油藏形成阶段、气藏形成阶段、气藏破坏阶段。
[Abstract]:Maoba gas reservoir is a medium type gas reservoir located in carbonate reservoir of the Lower Triassic Feixianguan formation. The fluid inclusions of the lower Triassic Feixianguan formation reservoir of Maoba gas reservoir in northeast Sichuan are studied systematically in this paper. The physical and chemical conditions of reservoir formation in Maoba gas reservoir are calculated and analyzed, the filling period of oil and gas is divided, and the time of reservoir formation is determined. The results show that the inclusions occur in carbonate solution pores of the Feixianguan formation in the Lower Triassic. In calcite and gypsum filled in caverns, the types of inclusions in the study area can be divided into H 2O inclusions and hydrocarbon H 2O inclusions. There are three types of hydrocarbon inclusions. The fluid inclusion assemblage of Maoba gas reservoir can be divided into four stages: the first stage of fluid inclusion is formed in the early diagenesis period, and the main inclusions are liquid H2O inclusions and gas-liquid H2O inclusions. The homogenization temperature range of gas-liquid H2O inclusions is from 85 鈩，

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