石油与天然气地质 ›› 2011, Vol. 32 ›› Issue (3): 459-471.doi: 10.11743/ogg20110319

• 石油与天然气地质 • 上一篇    下一篇

四川盆地奥陶系油气勘探前景

  

  • 出版日期:2011-06-28 发布日期:2011-09-23

Petroleum exploration potential of the Ordovician in the Sichuan Basin

  • Online:2011-06-28 Published:2011-09-23

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1479

被引次数

23

摘要：

摘要：在详细对比古隆起、斜坡地区奥陶系储层岩石学、水-岩流体活动特征基础之上，应用岩相学和地球化学方法，刻画奥陶系储层特征及其主控因素，并从油气成藏角度探讨了四川盆地奥陶系油气勘探前景。研究表明，奥陶系储层基质相对较致密，川中地区储集空间类型主要为粒内溶孔-粒间溶孔-晶间孔组合，川东南地区则是晶间孔和微裂缝组合，储层发育明显受到原始沉积环境、古岩溶作用、原油充注和裂解及破裂作用控制。生油窗期、生气窗期保存条件相对较好，形成了古油藏和古气藏；燕山—喜马拉雅期以来的隆升，使保存条件变差，古气藏完全遭受破坏。在川南和川东地区，红花园组和南津关组存在浅滩相颗粒白云岩或灰岩，具备发育潜在优质储层的条件；此外，震旦系和寒武系古油藏原油裂解气是天然气成藏的重要气源，为上覆的奥陶系油气成藏提供了气源保障。因此，川南和川东地区应是四川盆地奥陶系有利的勘探地区。

关键词: 关键词：储层特征；古油藏；古气藏, 天然气, 奥陶系；四川盆地

Abstract:

Abstract:Based on a detailed comparative study on reservoir petrology and fluid flow characteristics of waterrock between paleohigh and slope in the Sichuan Basin,the author characterized the features of the Ordovician reservoir and its major controlling factors by using petrographic and geochemical methods,and discussed the exploration potential of the Ordovician in the study area from the perspective of hydrocarbon accumulation.The matrix of the Ordovician reservoir is relatively tight.The reservoir spaces in central Sichuan Basin are dominated by intragranular dissolution pores,intergranular dissolution pores and intercrystalline pores,while that in southwestern Sichuan Basin are dominated by intercrystalline pores and mircofractures.Reservoir development is significantly controlled by the initial sedimentary environment,paleokarstification,oil charging and cracking,and fracturing.The sealing conditions were relatively good during oil and gas generation,leading to the formation of paleooil/gas pools which were completely destructed later due to the uplifting since the YanshanianHimalayan period.Shallow shoal limy or dolomitic grainstone occur in the Honghuayuan and Nanjinguan Formations in southern and eastern Sichuan Basin,and are potential highquality reservoirs.In addition,the gas from cracking of oil in the paleo oil pools in the Sinian and Cambrian is an important gas sources for the gas accumulation in overlying Ordovician.Therefore,the southern and eastern Sichuan Basin may be the most favorable areas for oil and gas exploration in the Ordovician.