石油与天然气地质 ›› 2016, Vol. 37 ›› Issue (5): 691-701.doi: 10.11743/ogg20160509

• [油气地质] • 上一篇    下一篇

鄂尔多斯盆地东北部奥陶系马五1+2储层特征及成因

熊鹰1, 李凌1,2, 文彩霞3, 侯云东3, 肖笛1, 钟原1, 聂万才3, 曹剑4, 谭秀成1,2   

  1. 1. 西南石油大学 油气藏地质及开发工程国家重点实验室, 四川 成都 610500;
    2. 西南石油大学 中国石油碳酸盐岩储层重点实验室沉积与成藏分室, 四川 成都 610500;
    3. 中国石油 长庆油田公司 勘探开发研究院, 陕西 西安 710018;
    4. 南京大学 地球科学与工程学院, 江苏 南京 210023
  • 收稿日期:2016-04-14 修回日期:2016-09-06 出版日期:2016-10-08 发布日期:2016-11-07
  • 第一作者简介:熊鹰(1993-),男,硕士研究生,储层地质学。E-mail:xiongying511602@163.com。
  • 基金项目:
    国家科技攻关重大专项(2016ZX05004002-001,2016ZX05004006-001-002)。

Characteristics and genesis of Ordovician Ma51+2 sub-member reservoir in northeastern Ordos Basin

Xiong Ying1, Li Ling1,2, Wen Caixia3, Hou Yundong3, Xiao Di1, Zhong Yuan1, Nie Wancai3, Cao Jian4, Tan Xiucheng1,2   

  1. 1. State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu, Sichuan 610500, China;
    2. PetroChina Deposition and Accumulation Department of Key Laboratory of Carbonate Reservoirs, Southwest Petroleum University, Chengdu, Sichuan 610500, China;
    3. Exploration and Development Research Institute of PetroChina Changqing Oilfield Company, Xi'an, Shaanxi 710018, China;
    4. School of Earth Sciences and Engineering, Nanjing University, Nanjing, Jiangsu 210023, China
  • Received:2016-04-14 Revised:2016-09-06 Online:2016-10-08 Published:2016-11-07
  • Contact: 谭秀成(1970-),男,教授、博士生导师,储集层沉积学,E-mail:tanxiucheng70@163.com E-mail:tanxiucheng70@163.com

摘要: 基于岩心、薄片和分析化验资料,研究鄂尔多斯盆地东北部奥陶系马五1+2亚段的储层特征及成因。结果表明,研究区马五1+2亚段具有多样性的储集岩类和储集空间类型。储集岩类包括含膏模孔泥粉晶云岩、颗粒云岩、砂糖状中-粗晶白云岩、微生物碳酸盐岩和溶洞充填砂质角砾云岩。相应的储集空间有膏模孔、渗流物间微孔、粒间(溶)孔、粒内溶孔、晶间(溶)孔、窗格孔和砾间残余孔洞。研究区储集层整体表现为低孔、低渗孔隙型。其中,储集性能以含膏模孔泥粉晶云岩最佳,但发育频率及规模一般;而颗粒云岩和溶洞充填砂质角砾云岩储、渗性能略低于前者,但分布频率及发育规模更大。储层成因分析发现,研究区储层发育主要受沉积微相、多期叠合型岩溶的控制,为典型的相控岩溶型储层。砂屑滩和膏云坪是储层发育和后期岩溶叠加改造的物质基础,未成熟期表生岩溶对膏质团块的溶蚀以及岩溶水沿早期砂屑滩孔渗层顺层流动溶蚀是储集层形成的关键,而成熟期表生岩溶叠加改造未成熟期表生岩溶及其混合充填作用则使得先期储集层遭到破坏或消失。

关键词: 表生岩溶, 储层特征, 储层成因, 马家沟组, 鄂尔多斯盆地

Abstract: Characteristics and genesis of Ma51+2 sub-member reservoir (the 1st and 2nd sub-member of the 5th member of Ordovician Majiagou Formation) in the northeastern Ordos Basin are studied based on core,thin section and physical property analysis.The result shows that diverse types of reservoir rocks and reservoir spaces occur in Ma51+2 sub-member in the study area.The reservoir rock types include gypsiferous micritic to very fine crystalline dolomite,grain dolomite,saccharoidal medium-coarse crystalline dolomite,microbial carbonate and sandy rubble dolomite with caverns filled.And the corresponding reservoir space types are gypsum mould pore,micropore between pore fillings,intergranular (dissolved) pore,intragranular dissolved pore,intercrystalline (dissolved) pore,fenestral pores,inter-breccia residual vuggs.The reservoirs in Ma51+2 sub-member are typical porous reservoirs with low porosity and low permeability as a whole.The micritic and very fine crystalline dolomite with gypsum mold pores have the best reservoir properties but fair frequency and scale of occurrence.In contrast,the grain dolomite and sandy breccia dolomite have poorer reservoir properties but larger frequency and scale of occurrence than the former.Reservoir genesis analysis indicates that the formation and distribution of the Ma51+2 sub-member reservoirs in this region are mainly controlled by sedimentary microfacies and multi-stage superimposed karstification,thus they are typical facies-controlling karst reservoirs.The psammitic banks and the gypsiferous dolomite flat provided the material foundation for the reservoir development and later karst reformation.The dissolution of gypsum clumps via epigenic karstification in the immature stage,the dissolution caused by layer-parallel flowing of karst water along the porous beds of early psammitic banks played a key role in the formation of the reservoirs.However,the overprint of epigenic karstification in the mature stage on that in the immature stage and the hybrid filling destroyed the earlier reservoirs or made them disappear.

Key words: epigenic karstification, reservoir characteristics, reservoir genesis, Majiagou Formation, Ordos Basin

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