【摘要】 为研究克拉美丽气田滴西地区石炭系巴塔玛依内山组火山岩储集层的流体演化过程,对储集层裂缝中的石英、方解石、黄铁矿等自生矿物进行了电子探针、流体包裹体及同位素分析研究。结果表明,Si O2主要来自深部热液流体,CO2来源具有深部热液、烃类流体混合改造的特征。在压力梯度与浮力驱使下,富含SO2等挥发分的含硅热液沿断层向上及两侧运移,分别形成具拱张-高温特征以及具隐爆-低温特征的石英脉。伴随深部流体由酸性向弱碱性的演化、压力的降低、CO2含量和盐度降低、温度变化,在收缩缝中沉淀出早期方解石。在岩体顶部长期暴露出地表地质背景下,当大气淡水与偏碱性盆地流体相遇时,在风化缝中形成保留渗流环境特征的方解石胶结物。埋藏期构造作用形成构造裂缝,烃类的充注-漏失使孔隙流体再次由酸性变为碱性,并在溶蚀孔缝中沉淀出晚期亮晶方解石。晚期热液作用的叠加形成磷灰石、方解石及黄铁矿矿物组合。石英、方解石等的充填作用使裂缝由开启变为闭合,对储层物性主要起破坏作用。更多还原

【Abstract】 In order to trace the processes of fluid evolution in the Carboniferous Batamayineishan Formation of the Kelameili Gas Field,EMPA,fluids inclusion and isotope studies of quartz,calcite and pyrite in fractures have been carried out. The results suggest that various types of fluids in volcanic rocks lead to the filling of quartz and calcite in fractures and associated alteration haloes. The silica in fluids was mainly derived from deep hydrothermal fluids,while carbon dioxide was likely to be the mixture of deep hydrothermal and hydrocarbon fluids. Siliceous hydrothermal fluids are rich in sulphur dioxide and other volatile components,which were transported by a pressure gradient and buoyancy,and circulated both laterally and vertically along the fractures,forming quartz veins and tension fractures under different temperature conditions. Moreover,changes in salinity,pressure,carbon dioxide contents of deep fluids would change the composition of fluids from acidic to weakly alkaline,resulting in earlier calcite precipitated in contraction fractures and weathered fractures.Tectonic uplift lead to the exposure of volcanic rocks. Fresh water would mix with the weakly alkaline fluids,precipitating calcite cements in the weathered fractures. In structural fractures formed by tectonic movements during the burial period,filling and leakage of hydrocarbons changed pore fluids from acidic to alkaline,depositing late sparry calcite in dissolution fractures. The mineral association of apatite,calcite and pyrite are formed by the superimposition of late hydrothermal processes. The existence of alteration halo and filling minerals provided the basis for the formation of secondary pores.更多还原