中国石油勘探 ›› 2020, Vol. 25 ›› Issue (1): 78-92.DOI: 10.3969/j.issn.1672-7703.2020.01.008

• 勘探案例 • 上一篇    下一篇

鄂尔多斯盆地延长组7 段Ⅱ类页岩油风险勘探突破及其意义

付金华1,2 ,李士祥1,3 ,侯雨庭1,4 ,周新平1,3 , 刘江艳1,3 , 李树同5   

  1. 1 低渗透油气田勘探开发国家工程实验室;2 中国石油长庆油田分公司;3 中国石油长庆油田公司勘探开发研究院;4 中国石油长庆油田分公司勘探事业部;5 甘肃省油气资源研究重点实验室
  • 出版日期:2020-01-15 发布日期:2019-12-31
  • 基金资助:
    国家科技重大专项“大型油气田及煤层气开发”(2016ZX05050;2017ZX05001002);国家重点基础研究发展计划(973 计划) “淡水湖盆细粒沉积与富有机质页岩形成机理”(2014CB239003)。

Breakthrough of risk exploration for Class II shale oil in Chang 7 member of the Yanchang Formation and its significance in the Ordos Basin

Fu Jinhua1.2, Li Shixiang1.3, Hou Yuting1.3,Zhou Xinping1.3,Liu Jiangyan1.3, Li Shutong5   

  1. 1 National Engineering Laboratory for Exploration and Develop ment of Low-Permeability Oil & Gas Fields; 2 Petr oChina Changqing Oilfield Company; 3 Exploration and Development Research Institute of PetroChina Changqing Oilfield Company; 4 Exploration Department of PetroC'hina C'hangying Oilfield Company; 5 Key Laboratory of Petroleum Resources, Gansu Province
  • Online:2020-01-15 Published:2019-12-31
  • Supported by:
     

摘要: 2019 年长庆油田在鄂尔多斯盆地延长组72 段(长73 段)厚层泥页岩夹薄层粉细砂岩类型的页岩油中, 部署2 口水平井开展风险勘探攻关试验。城页1 井和城页2 井两口水平井试油分获121.38t/d 和108.38t/d 的高产油流, 该发现对推进盆地长7 段最大湖侵期沉积的页岩油新类型勘探意义重大。重点利用城页1 井、城页2 井两口水平井及 城页1 井导眼井的岩心、薄片、测井及地球化学资料,对长7 段页岩油新类型储集条件及资源潜力进行了研究。研究 表明,两口水平井水平段长7 段页岩油新类型的储层主要为厚层泥页岩中夹多薄层粉—细砂岩型,单砂体的垂向单层 厚1~5m、侧向宽度100~300m,水平方向岩性变化频繁。储层碎屑颗粒粒径0.10~0.12mm,石英、长石含量一般 在50%~78%。储层孔隙类型为粒间孔、溶蚀孔、晶间孔及裂缝,最大孔径可达21μm,孔隙半径集中分布在0.1~3μm, 水平井段的储层中天然高导缝、微断裂发育且呈东西向展布。储层的孔隙度为6%~12%,渗透率一般小于0.3mD。 综合利用岩石热解法、石油醚抽提法、二氯甲烷萃取法等方法,对城页井区220km2 范围内长72 段泥页岩及砂岩可动 烃页岩油资源量进行了评价,初步评价结果约为(0.692~0.783)×108t。盆地该页岩油类型分布面积约1.5×104km2, 该类型页岩油远景资源量达33×108t。

 

关键词: 水平井, 风险勘探, 延长组, Ⅱ页岩油, 鄂尔多斯盆地

Abstract: In 2019, the Changqing Oilfield deployed 2 horizontal wells, Chengye-1 and Chengye-2 to carry out risk exploration research tests for shale oil in thick shale interlayered with thin siltstone and fine-sandstone layers (Class II shale oil) in the 73 member of the Yanchang Formation (the Chang 73 member) in the Ordos Basin. High-production oil flows of 121.38 t/d in Well Chengye-1 and 108.38 t/d in Well Chengye-2 have been obtained, which significantly boosts the exploration progress of Class II shale oil. In this paper, cores, thin sections, well loggings and geochemical data from the two horizontal wells, Chengye-1 and Chengye-2, and the pilot well of Well Chengye-1 have been used to study the reservoir conditions and resource potential of Class II shale oil reservoirs in the Chang 73 member. The results show that the reservoir type penetrated by horizontal sections of the two horizontal wells is mainly thick shale interlayered with several thin siltstone and fine-sandstone layers. Thickness of the single layer sand body is 1?5 m. Lateral extension length of single sand body in the horizontal direction is generally in the range 25?50 m and the lateral width of sand bodies is 100?300 m. The distribution area of the single sand body is relatively small. The reservoir types are intergranular pores, dissolution pores, pores, inter-crystalline pores, organic pores and fractures. The intergranular pore radius is concentrated in the range 0.1?3 μm with the maximum of 21 μm. In reservoirs penetrated by pilot sections and horizontal sections, high-conductive fractures are well developed and distributed in an E-W orientation. The porosity of the sandstone reservoirs is 6?12%, and permeability is generally less than 0.3 mD. Shale reservoirs offer poor reservoir performance, with porosity less than 2% and permeability less than 0.01 mD. Using methods such as rock pyrolysis, petroleum ether extraction and dichloromethane extraction, movable shale oil resources in shale and sandstone in the Chang 73 member within a 220 km2 area of the Chengye well block have been evaluated. Preliminary evaluation results indicate resources of (0.692?0.783)×108 t. The distribution area of Class II shale oil in the Chang 73 member in the Ordos Basin is about 1.5×104 km2, and the prospective resources of Class II shale oil in the Chang 73 member are 33×108 t.

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