• 责任者：Chen Hongde (State Key Laboratory of Oil and Gas Geology and Exploitation ; Chengdu University of Technology ; Chengdu 610059 ; China) ; Hu Sihan
• 刊名：Natural Gas Industry
• 出版年：2013
• 卷期：33(10)
• 关键词：岩礁储集层 ; reef reservoirs ; 鄂尔多斯盆地 ; Ordos Basin
• 页码：p.18-24
• 图表：5 illus., 1 table, 10 refs.
• 分类号：1003
• issnNo：ISSN1000-0976
• isbnNo：CN51-1179/TE

     In addition to the successful exploration of carbonate karst reservoirs on the top of the Ordovician Majiagou Fm in the Ordos Basin, breakthroughs of gas exploration have also been made in nonkarst dolomite reservoirs. Core observation, thin section authentication, physical property analysis and logging data were integrated to study the sedimentary microfacies of Ma55 Ma56 （the 5th and 6th  intervals of the fifth member of the Ordovician Majiagou Fm） on the east side of the paleouplift of the Ordos Basin, and to analyze the features and major control factors of the nonkarst dolomite reservoirs. The following findings were achieved. a. The reservoir rocks are dominated by dolarenitedolorudites and crystalline dolomites. b. The types of reservoir space are mainly of residual intergranular pores, intercrystalline pores and dissolution pores, indicating low porosity and low permeability reservoirs with strong heterogeneity. c. Their depositional settings are restricted platform which can be further divided into several sedimentary microfacies such as tidalfront beach, dolomitedominated tidal flat, dolomitedominated lagoon, limestonedominated lagoon and gypsumdominated lagoon, etc. d. The distribution of reservoirs is significantly controlled by the tidalfront beach microfacies near the paleouplift and selective burial dolomitization. e. Various destructive diagenesis such as recrystallization, cementation, compaction and pressure solution as well as filling led to the tightening of reservoirs. f. The development of fractures improves the physical properties of the dolomite reservoirs and connects the preserved isolated residual intergranular pores and dissolution pores. In summary, the burial dolomitization, alongbedding karstification and fracture modification in the tidalfront beach microfacies are the key factors controlling reservoir development, and are favorable for the development of relatively high quality dolomite reservoirs.