陆相页岩油“甜点”段评价关键参数界限探讨

Limits of critical parameters for sweet-spot interval evaluation of lacustrine shale oil

李志明 刘雅慧 何晋译 孙中良 冷筠滢 李楚雄 贾梦瑶 徐二社 刘鹏 黎茂稳 曹婷婷 钱门辉 朱峰

Zhiming LI Yahui LIU Jinyi HE Zhongliang SUN Junying LENG Chuxiong LI Mengyao JIA Ershe XU Peng LIU Maowen LI Tingting CAO Menhui QIAN Feng ZHU

合理确定陆相页岩油“甜点”段评价关键参数的界限，是实现经济效益开发的关键。根据陆相页岩油探井现场观测与室内分析、综合前人研究成果与勘探开发实践成效，系统研究了不同类型页岩油“甜点”段（总有机碳含量）、（镜质体反射率）、（游离烃含量）、孔隙度、渗透率、（含油饱和度指数）以及脆性矿物含量等关键参数的界限。研究表明：①源-储一体的混积型和页岩型页岩油“甜点”段最低门限应大于1.0 %或2.0 %，最高门限值不宜超过6.0 %。②盐水-咸水、咸化-半咸水和微咸水-淡水湖盆地烃源层系页岩油“甜点”段最低门限分别为0.50 %，0.60 %和0.80 %。③受分析样品处置方式等因素影响，建议“甜点”层段下限取1.0 %时，“甜点”段常规热解和密闭冷冻碎样热解下限分别取1.0 mg/g和2.0 mg/g。当“甜点”层段下限取2.0 %时，“甜点”段常规热解和密闭冷冻碎样热解下限分别取2.0 mg/g和4.0 mg/g。④夹层型页岩油“甜点”段的孔隙度和渗透率最低门限分别为5.0 %和0.01×10 μm。纹层状、层状构造及裂缝发育的页岩型和混积型页岩油“甜点”段孔隙度和水平渗透率最低门限分别为4.0 %和0.01×10 μm。⑤页岩型和混积型页岩油“甜点”段，取值下限为100 mg/g或200 mg/g。夹层型页岩油“甜点”段，取值下限为300 mg/g或400 mg/g。⑥页岩油“甜点”段脆性矿物含量下限为65.0 %。研究结果可为低油价时期页岩油勘探开发聚焦到真正的页岩油“甜点”段并实现规模效益开发奠定基础。

Determining the limits of critical parameters for sweet-spot intercal evaluation of lacustrine shale oil is the key to commercial shale oil exploitation. Based on the on-site observations and lab analysis of lacustrine shale oil exploratory wells， supplemented by previous research results and achievements in exploration and development practices， we try to determine the limits of critical parameters for sweet-spot intervals of diverse shale oil types， including the total organic carbon （） content， vitrinite reflectance （）， pyrolytic hydrocarbon content （）， porosity and permeability， oil saturation index （）， and brittle mineral content. Findings suggest that for the shale oil sweet-spot intervals of the mixed type with source rock-reservoir integrated and the pure shale type， the lower limit of content is greater than 1.0 % or 2.0 %， and the upper limit should not exceed 6.0 %. For sweet-spot intervals in the source rock measures of brine-saline， saline-brackish， and brackish-fresh lacustrine basins， the lower limits of are 0.50 %， 0.60 %， and 0.80 %， respectively. Regarding ， two scenarios are recommended considering factors such as sample preparation： for low limit of content at 1.0 %， the lower limit of is 1.0 mg/g （conventional pyrolysis） or 2.0 mg/g （pyrolysis of sealed and frozen crushed samples）； for low limit of content at 2.0 %， the lower limit of is 2.0 mg/g （conventional pyrolysis） or 4.0 mg/g （pyrolysis of sealed and frozen crushed samples）. The lower limits of porosity and permeability are 5.0 % and 0.01×10 μm， respectively for the intercalated-type sweet-spot intervals of shale oil， and are 4.0 % and 0.01×10 μm， respectively for the pure shale-type and mixed-type sweet-spot intervals with laminated and layered textures and well-developed fractures. The lower limit of is 100 mg/g or 200 mg/g for the pure shale-type and mixed-type and is 300 mg/g or 400 mg/g for intercalated-type. The lower limit of the brittle mineral content is 65.0 %. These findings can lay the foundation for genuine shale oil sweet-spot interval development to achieve commercial shale oil exploration and exploitation in low-oil-price environment.

10.11743/ogg20230610