石油学报 ›› 2019, Vol. 40 ›› Issue (8): 997-1012.DOI: 10.7623/syxb201908011

• 典型油气田 • 上一篇    下一篇

陆相页岩油甜点地质特征与勘探关键技术——以沧东凹陷孔店组二段为例

蒲秀刚, 金凤鸣, 韩文中, 时战楠, 蔡爱兵, 王爱国, 官全胜, 姜文亚, 张伟   

  1. 中国石油大港油田公司 天津 300280
  • 收稿日期:2019-06-27 修回日期:2019-07-15 出版日期:2019-08-25 发布日期:2019-08-28
  • 通讯作者: 蒲秀刚,男,1968年12月生,1990年获长春地质学院学士学位,2004年获中国矿业大学(北京)博士学位,现为中国石油大港油田公司教授级高级工程师,主要从事油气勘探领域中的地质研究与管理工作。Email:puxgang@petrochina.com.cn
  • 作者简介:蒲秀刚,男,1968年12月生,1990年获长春地质学院学士学位,2004年获中国矿业大学(北京)博士学位,现为中国石油大港油田公司教授级高级工程师,主要从事油气勘探领域中的地质研究与管理工作。Email:puxgang@petrochina.com.cn
  • 基金资助:

    中国石油天然气集团公司科技重大专项"大港油区效益增储稳产关键技术研究与应用"(2018E-11)资助。

Sweet spots geological characteristics and key exploration technologies of continental shale oil: a case study of Member 2 of Kongdian Formation in Cangdong sag

Pu Xiugang, Jin Fengming, Han Wenzhong, Shi Zhannan, Cai Aibing, Wang Aiguo, Guan Quansheng, Jiang Wenya, Zhang Wei   

  1. PetroChina Dagang Oilfield Company, Tianjin 300280, China
  • Received:2019-06-27 Revised:2019-07-15 Online:2019-08-25 Published:2019-08-28

摘要:

页岩油气等非常规油气资源已成为油气勘探开发的重要接替领域。渤海湾盆地沧东凹陷孔店组二段(孔二段)陆相页岩油十分丰富,但面临着构造复杂、储层非均质性强、埋深大等难题。在进行635.8 m系统取心、厘米级精细描述和上万块次分析联测的基础上,开展了页岩油成藏地质特征与勘探关键技术的攻关研究,形成了"选准甜点区、打准甜点段、压准甜点层、测准裂缝区"的"四准"技术。研究结果表明,孔二段陆相页岩层系可划分为长英质页岩、含灰白云质页岩和混合质页岩,矿物成分多样,层理结构发育,源岩品质好,热演化程度中等,储层致密但微孔缝发育,含油饱和度高,脆性矿物含量高,展示了孔二段页岩油具有良好的勘探前景。通过沉积学研究、总有机碳含量及镜质体反射率评价、脆性矿物计算、地震融合反演等综合评价确定了孔二段I类甜点面积为126 km2,指导了GD1701H井和GD1702H井的水平井井位部署;通过"精细标定追小层、精细反演定箱体、精细落实保入窗、实施调整追甜点"等措施确保了两口水平井96%的甜点钻遇率;通过"一优五高"选点实现了压裂段簇的差异设计;微地震及电位法监测结果表明,体积压裂改造形成的压裂缝长300~400 m、高120 m,缝控体积约0.07 km3,两口水平井最高产油量分别达66 t/d和53 t/d,实现了页岩油缝控储量的有效动用。孔二段页岩油勘探实践表明陆相页岩油效益勘探开发潜力大,"四准"技术是页岩油高效动用的关键。

关键词: 页岩油, 甜点评价, 压裂段簇, 孔二段, 沧东凹陷, 渤海湾盆地

Abstract:

Under the general trend of stepping-up oil and gas exploration and development in China, the unconventional oil and gas resources such as shale oil and gas have become an important alternative. Abundant continental shale oil resources are developed in Member 2 of Kongdian Formation (Ek2) of the Cangdong sag in the Huanghua depression of the Bohai Bay Basin which has complex structure, strong heterogeneity, and large buried depth, thus, the geological characteristic of shale oil accumulation and key exploration technologies are investigated on base of the system coring of 635.8 m, centimeter-level fine description and analysis of over ten thousand samples, therefore, the "four accurate" technologies have been developed, including the accurate selection of sweet spot areas, accurate drilling of sweet spot layers, accurate fracturing of sweet spot layers and accurate measure of fracture-rich sections. The results show that the continental shale strata in Member 2 of Kongdian Formation can be divided into three types:felsic shale, limy dolomitic shale and mixed shale. The Member 2 of Kongdian Formation is characterized by diverse mineral components, abundant laminae, good source rocks and medium thermal evolution degree, tight reservoir with rich micropore and microfractures, high oil saturation and brittle mineral content, indicating good prospect of shale oil exploration. Through sedimentological study, TOC and Ro evaluation, brittle mineral calculation, and seismic fusion inversion, a total of 126 km2 of Class I sweet spots in Member 2 of Kongdian Formation was delineated comprehensively, which guides horizontal well deployment (Well GD1701H and Well GD1702H). The drilling rate of sweet spot of these two horizontal wells is up to 96% by tracing thin layer through fine calibration, locating compartment through fine inversion, ensuring window entry through precise positioning, and tracking sweet spot through adjustment. The "one-excellent and five-highs" criterion is used to select perforation points to realize differential designs of fracturing intervals and clusters. Micro-seismic and potentiometry monitoring show that the artificial fractures formed by volumetric fracturing are 300-400 m long and 120 m high, and control a volume of about 0.07 km3. The maximum daily oil production of two horizontal wells is 66 t and 53 t respectively to realize the economic exploitation of shale oil reserves controlled by fractures. The shale oil exploration in Member 2 of Kongdian Formation shows that the continental shale oil has great potential of exploration and development, and the above technologies are critical and effective for shale oil efficient recovery.

Key words: shale oil, sweet spot evaluation, fracturing intervals and perforation clusters, Member 2 of Kongdian Formation, Cangdong sag, Bohai Bay Basin

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