Origin and reservoir characteristics of Ordovician dolostones in the Ordos Basin
Dolomite is one of the most important rock types for the development of the Ordovician effective reservoirs in the Ordos Basin. Its genesis remains controversial due to its complex and variable rock texture and occurrence. In this paper, through analysis of macroscopic regional geological background...
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| Format: | Article |
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KeAi Communications Co., Ltd.
2017-03-01
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| Series: | Natural Gas Industry B |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2352854017300797 |
| _version_ | 1797288497032200192 |
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| author | Hongping Bao Fan Yang Zhenghong Cai Qianping Wang Chunying Wu |
| author_facet | Hongping Bao Fan Yang Zhenghong Cai Qianping Wang Chunying Wu |
| author_sort | Hongping Bao |
| collection | DOAJ |
| description | Dolomite is one of the most important rock types for the development of the Ordovician effective reservoirs in the Ordos Basin. Its genesis remains controversial due to its complex and variable rock texture and occurrence. In this paper, through analysis of macroscopic regional geological background, microscopic rock texture, mineralogy, and geochemistry, the Ordovician dolomites in this area are divided into three types, i.e., micrite–fine-powder crystal, coarse-powder crystal, and fine (medium) crystal. It is pointed out that they were formed in three different dolomitization diagenetic environments, namely, penecontemporaneous dolomitization by evaporative pumping, mixture dolomitization of freshwater and magnesium-rich brine, and seepage–reflux dolomitization, respectively. In terms of horizon and spatial distribution, they represent the features of “strata-controlled” and “region-specific”. The analysis of genesis provides the following findings. First, the three types of dolomitization are correlated to certain extent in terms of temporal–spatial evolution. In other words, they were all originated along with the deposition of gypsum mineral under evaporation background. Second, the main pore types, i.e., dissolved pores, intercrystalline pores, and organic framework, were respectively formed in three types of dolomites. They generally distributed in “specific” type of dolomite, which indicates that the pore genesis is closely related to dolomitization diagenesis environment. Third, the development and distribution of effective dolomite reservoirs is mainly subject to three types of elements, such as primary sedimentary facies belts, diagenetic environment controlling regional dolomitization, and sequence boundary caused by variation of relative sea level. |
| first_indexed | 2024-03-07T18:50:21Z |
| format | Article |
| id | doaj.art-5316f1451f61415b8cb13e9838e4c4aa |
| institution | Directory Open Access Journal |
| issn | 2352-8540 |
| language | English |
| last_indexed | 2024-03-07T18:50:21Z |
| publishDate | 2017-03-01 |
| publisher | KeAi Communications Co., Ltd. |
| record_format | Article |
| series | Natural Gas Industry B |
| spelling | doaj.art-5316f1451f61415b8cb13e9838e4c4aa2024-03-02T01:46:38ZengKeAi Communications Co., Ltd.Natural Gas Industry B2352-85402017-03-014210611910.1016/j.ngib.2017.07.015Origin and reservoir characteristics of Ordovician dolostones in the Ordos BasinHongping Bao0Fan Yang1Zhenghong Cai2Qianping Wang3Chunying Wu4PetroChina Changqing Oilfield Company, Xi'an, Shaanxi 710018, ChinaPetroChina Changqing Oilfield Company, Xi'an, Shaanxi 710018, ChinaPetroChina Changqing Oilfield Company, Xi'an, Shaanxi 710018, ChinaPetroChina Changqing Oilfield Company, Xi'an, Shaanxi 710018, ChinaPetroChina Changqing Oilfield Company, Xi'an, Shaanxi 710018, ChinaDolomite is one of the most important rock types for the development of the Ordovician effective reservoirs in the Ordos Basin. Its genesis remains controversial due to its complex and variable rock texture and occurrence. In this paper, through analysis of macroscopic regional geological background, microscopic rock texture, mineralogy, and geochemistry, the Ordovician dolomites in this area are divided into three types, i.e., micrite–fine-powder crystal, coarse-powder crystal, and fine (medium) crystal. It is pointed out that they were formed in three different dolomitization diagenetic environments, namely, penecontemporaneous dolomitization by evaporative pumping, mixture dolomitization of freshwater and magnesium-rich brine, and seepage–reflux dolomitization, respectively. In terms of horizon and spatial distribution, they represent the features of “strata-controlled” and “region-specific”. The analysis of genesis provides the following findings. First, the three types of dolomitization are correlated to certain extent in terms of temporal–spatial evolution. In other words, they were all originated along with the deposition of gypsum mineral under evaporation background. Second, the main pore types, i.e., dissolved pores, intercrystalline pores, and organic framework, were respectively formed in three types of dolomites. They generally distributed in “specific” type of dolomite, which indicates that the pore genesis is closely related to dolomitization diagenesis environment. Third, the development and distribution of effective dolomite reservoirs is mainly subject to three types of elements, such as primary sedimentary facies belts, diagenetic environment controlling regional dolomitization, and sequence boundary caused by variation of relative sea level.http://www.sciencedirect.com/science/article/pii/S2352854017300797Ordos BasinOrdovicianGenesis of dolomiteGeochemistryReservoirDistribution of dolomitesStrata-controlledRegion-specific |
| spellingShingle | Hongping Bao Fan Yang Zhenghong Cai Qianping Wang Chunying Wu Origin and reservoir characteristics of Ordovician dolostones in the Ordos Basin Natural Gas Industry B Ordos Basin Ordovician Genesis of dolomite Geochemistry Reservoir Distribution of dolomites Strata-controlled Region-specific |
| title | Origin and reservoir characteristics of Ordovician dolostones in the Ordos Basin |
| title_full | Origin and reservoir characteristics of Ordovician dolostones in the Ordos Basin |
| title_fullStr | Origin and reservoir characteristics of Ordovician dolostones in the Ordos Basin |
| title_full_unstemmed | Origin and reservoir characteristics of Ordovician dolostones in the Ordos Basin |
| title_short | Origin and reservoir characteristics of Ordovician dolostones in the Ordos Basin |
| title_sort | origin and reservoir characteristics of ordovician dolostones in the ordos basin |
| topic | Ordos Basin Ordovician Genesis of dolomite Geochemistry Reservoir Distribution of dolomites Strata-controlled Region-specific |
| url | http://www.sciencedirect.com/science/article/pii/S2352854017300797 |
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