石油与天然气地质 ›› 2010, Vol. 31 ›› Issue (4): 481-485.doi: 10.11743/ogg20100412

• 石油与天然气地质 • 上一篇    下一篇

准噶尔盆地乌尔禾油田凝灰质岩成因及储层特征

  

  1. 中国石油天然气股份有限公司杭州地质研究院,浙江杭州310023
  • 出版日期:2010-08-28 发布日期:2010-10-20
  • 作者简介:宫清顺(1979—),男,硕士,沉积储层与石油地质。

Genesis and reservoir features of tuffaceous rocks in Wuerhe oilfield of the Junggar Basin

  • Online:2010-08-28 Published:2010-10-20

摘要:

基于岩石薄片、铸体照片、岩心、测井和地震资料等分析,对准噶尔盆地乌尔禾油田二叠系乌尔禾组特殊凝灰质岩成因及储集特征进行详细分析。岩石类型包括凝灰岩、沉凝灰岩和凝灰质砂砾岩;电测曲线呈现高电阻率、低声波时差的电性特征。分析表明,乌尔禾组凝灰质岩成因环境为封闭-半封闭的湖湾环境,由火山灰与正常陆源碎屑物混合堆积、固结成岩。同生期高盐度、碱性水介质条件为火山灰水解蚀变提供物质基础,形成云化(沉)凝灰岩,并析出方沸石。储集空间包括溶蚀孔隙、泄水道孔和裂缝。双孔介质特征改善了储层的储集性能,对油气富集起重要控制作用,控制了油藏分布及油藏规模。

关键词: 凝灰质岩, 湖湾环境, 双孔介质储层, 乌尔禾油田, 准噶尔盆地

Abstract:

Based on analyses of thin section,core observation,logging and seism ic data,we studied the genesis of tuffaceous rocks and their reservoir features in the Permian Wuerhe Formation in Wuerhe Oilfield,Junggar Basin. The rocks can be classified into tuff,tuffites and tuffaceous sandstone and conglomerate and show high resistivity and low interval transit time in logging curves. The study shows that the sedimentary environment of the Formation is enclosed or semi-enclosed lake bay,and the sediments are composed mainly of volcanic ash and terrigenous clastics. Syngenetic high-salinity and alkaline water body provided favorable conditions for hydrolysis and alteration of the deposited volcanic ash. During the process,dolomitic tuffites were formed and analcite was precipitated. These rocks have different reservoir space(dual porosity media),including dissolved vugs,sluiceˉway and fractures. The dual porosity feature of the rocks improves the poroperm characteristics and controls the accumulation and distribution of hydrocarbons inWuerhe oilfied.

Key words: tuffaceous rock, lake bay, dual-porosity reservoir, Wuerhe oilfield, Junggar Basin

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