【摘要】 2019年长庆油田分公司针对鄂尔多斯盆地延长组7₃段（长7₃段）厚层泥页岩夹薄层粉—细砂岩类型的页岩油（Ⅱ类页岩油）,部署城页1井和城页2井两口水平井开展风险勘探攻关试验,两口水平井试油分获121.38t/d和108.38t/d的高产油流,有力推动了Ⅱ类页岩油的勘探进程。重点利用城页1、城页2两口水平井及城页1井导眼井的岩心、薄片、测井及地球化学资料,对长7₃段Ⅱ类页岩油储层储集条件及资源潜力进行研究。研究表明,两口水平井水平段储层类型主要为厚层泥页岩夹多层薄层粉—细砂岩,单砂体的垂向单层厚度主要为1～5m、水平段砂体横向延伸长度主要分布在25～50m、侧向宽度主要为100～300m,单砂体规模较小。储层储集空间类型有粒间孔、溶蚀孔、粒内孔、晶间孔、有机质孔及裂缝等,其中粒间孔孔隙半径集中分布在0.1～3μm,最大可达21μm,导眼段和水平井段的储层中高导缝、裂缝发育且呈东西向展布。砂岩储层的孔隙度主要为6%～12%,渗透率一般小于0.3mD;泥页岩储层储集性能差,孔隙度一般小于2%,渗透率小于0.01mD。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80区块220km²范围内长7₃段泥页岩及砂岩可动烃页岩油资源量进行评价,初步评价结果约为（0.692～0.783）×10⁸t。鄂尔多斯盆地长7₃段Ⅱ类页岩油分布面积约为1.5×10⁴km²,综合评价长7₃段Ⅱ类页岩油远景资源量达33×10⁸t。更多还原

【Abstract】 In 2019,Changqing Oilfield deployed two horizontal wells to carry out risk exploration research test for shale oil of thick shale interlayered with thin siltstone and fine-sandstone layers （Class Ⅱ shale oil） in the 7₃ member of Yanchang Formation （Chang 7₃ member） in the Ordos Basin.High-production oil flow of 121.38 t/d and 108.38 t/d have been obtained in the two horizontal wells,Well Chengye-1 and Well Chengye-2,respectively,which significantly promoted the exploration progress of Class Ⅱ shale oil.In this paper,cores,thin sections,well loggings and geochemical data of two horizontal wells,Well Chengye-1 and Well Chengye 2,and pilot well of Well Chengye-1 were mainly used to study the reservoir conditions and resource potential of ClassⅡ 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 single layer sand body is 1-5 m.Lateral extension length of single sand body in horizontal direction is mainly distributed in 25-50 m and lateral wide of sand bodies is 100-300m.The distribution area of single sand body is relatively small.The reservoir types are intergranular pores,dissolution pores,intragranular pores,inter-crystalline pores,organic pores and fractures.The intergranular pore radius is concentrated in 0.1-3 μm.The maximum is 21 μm.In the reservoirs penetrated by pilot section and horizontal sections,the high-conductive fractures and fractures are well developed and distributed in E-W direction.The porosity of the sandstone reservoirs is 6%-12%,and the permeability is generally less than 0.3 mD.Shale reservoirs are of poor reservoir performance with porosity less than 2% and permeability less than 0.01 mD.By 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 the area of 220 km² of Chengye well block has been evaluated.The preliminary evaluation results are （0.692-0.783）×10⁸t.The distribution area of ClassⅡ shale oil in the Chang 7₃ member in the Ordos Basin is about 1.5×10⁴km²,and the prospective resources of Class Ⅱ shale oil in the Chang 7₃ member is 33×10⁸t.更多还原