石油与天然气地质 ›› 2016, Vol. 37 ›› Issue (2): 210-217.doi: 10.11743/ogg20160209

• 油气地质 • 上一篇    下一篇

鄂尔多斯盆地大牛地气田奥陶系“垮塌”型岩溶储层发育规律

丁晓琪1,2, 张哨楠2, 潘怀孝3, 李良3, 贾会冲3   

  1. 1. 成都理工大学能源学院, 四川成都 610059;
    2. 西南石油大学油气藏地质开发工程国家重点实验室, 四川成都 610500;
    3. 中国石化华北油气分公司, 河南郑州 450006
  • 收稿日期:2015-10-21 修回日期:2015-12-21 出版日期:2016-04-08 发布日期:2016-04-29
  • 第一作者简介:丁晓琪(1981-),男,博士、副教授,石油地质学。E-mail:xiaoqiding@qq.com。
  • 基金项目:
    国家科技重大专项(2011ZX05045);成都理工大学中青年骨干教师培养计划项目;成都理工大学校级科研团队资助项目(KYTD201401)。

Development patterns of collapse-type karst reservoirs in the Ordovician of Daniudi gasfield, Ordos Basin

Ding Xiaoqi1,2, Zhang Shaonan2, Pan Huaixiao3, Li Liang3, Jia Huichong3   

  1. 1. Energy College, Chengdu University of Technology, Chengdu, Sichuan 610059, China;
    2. State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu, Sichuan 610500, China;
    3. SINOPEC North China Company, Zhengzhou, Henan 450006, China
  • Received:2015-10-21 Revised:2015-12-21 Online:2016-04-08 Published:2016-04-29

摘要: 随着水平井压裂技术在大牛地气田奥陶系风化壳气藏开发中的成功运用,低孔、低渗、强非均质性的岩溶储层显示出良好的天然气开发潜力,储层发育规律是风化壳成藏的关键。通过岩心观察,结合大量的测井资料,利用岩石相进行岩溶旋回和储层发育规律的研究,结果表明:①奥陶系马家沟组发育3期岩溶,上部两期岩溶规模较大,下部第三期岩溶规模较小,风化壳储层的发育主要与上部两期岩溶有关;②膏质云岩、泥云岩的长期溶蚀,导致水平洞穴层顶板发生破裂,部分上覆地层垮塌,最终形成一套厚层的岩溶角砾岩;③储层主要发育在岩溶强度相对较弱的区域,平面上主要发育在岩溶斜坡的残丘,纵向上则发育在上部两期岩溶保存相对完整的垂直渗流带,发育的岩石相为裂纹-镶嵌角砾岩相。利用岩溶旋回和岩相对有利储层发育区进行了预测,指明了下一步天然气勘探开发的方向。

关键词: 岩溶, 储层, 岩相, 奥陶系, 大牛地气田, 鄂尔多斯盆地

Abstract: Due to wide application of horizontal well fracturing technology in the Ordovician weathering crust reservoirs of Daniudi gasfield, Ordos Basin, karst reservoirs exhibit its great potential of gas production, regardless of its low porosity, permeability and strong heterogeneity.However, development pattern of reservoir is the key of gas accumulation in karst reservoirs.Karst cycles and reservoirs distribution are studied by using lithofacies based on core observation and well-logging interpretation.The following results were obtained.(1) Three Karst cycles can be identified in the Ordovician Majiagou Formation.The upper two karst cycles formed in the earlier time and are larger in scale than the lower one; therefore the development of karst reservoirs are mainly related to the upper two karst cycles.(2) The long-term dissolution of gypsiferous dolostone and muddy dolostone layers produces fractures in cave-roof zone and finally led to the collapse of overlying strata, forming a thick layer of breccias.(3) Reservoirs are mainly developed in areas with relatively weak karst intensity.Laterally, they mainly occur in monadnock of palaeogeomorphology slope, while vertically, they are distributed in the intact vadose zones of upper two karst cycles.The lithofacies are dominated by crackle-mosaic breccias lithofacies.The research on karst cycles and lithofacies will play significant roles in the reservoir predication for the following gas exploration.

Key words: karst, reservoir, lithofacies, Ordovician, Daniudi gasfield, Ordos Basin

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