鄂尔多斯盆地页岩油水平井体积压裂改造策略思考

鄂尔多斯盆地页岩油具有压力系数低、脆性指数低、纵向夹层多以及非均质性强等特点，采用水平井体积压裂技术可以大幅度提高单井产量，但低油价下难以实现经济有效开发。以该盆地矿场实践大数据为基础，建立了体积压裂效果定量评价方法，提出了体积压裂改造策略和下步工程攻关方向。在建立水平井地质工程综合品质分段分级评价新标准和储层类型精细分类的基础之上，基于9口水平井112段产液剖面测试结果得出：I类和II类储层改造段数占比为85.2%，产出占比高达96.4%，为主要产能贡献段；III类储层改造段数占比为14.8%，产出占比仅占3.6%，贡献程度最低；应优先改造I类和II类储层，III类储层选择性改造。影响产能的主控因素依次为：油层长度、进液强度、布缝密度、脆性指数、加砂强度、渗透率、施工排量、孔隙度、水平应力差及含油饱和度。储层物质基础是获得高产能的首要条件，提高缝网波及体积是实现非常规油气产能最大化的重要途径。研究成果可为盆地页岩油水平井体积压裂优化设计提供科学依据，有力助推页岩油规模效益开发。

Considerations on the strategy of volume fracturing for shale oil horizontal wells in Ordos Basin

Shale oil in Ordos Basin has the characteristics of low pressure coefficient， low brittleness index and vertical multi-interlayer. Horizontal well and volume fracturing technology can greatly increase the production of single well， but it is difficult to achieve economic and effective development under low oil price. On the basis of big data's field practice in the basin， a quantitative evaluation method of volume fracturing effect was established， which puts forward the volume fracturing transformation strategy and the direction of the next project. On the basis of the establishment of a new sectional classification evaluation standard for the comprehensive geological engineering quality of horizontal wells and the fine classification of reservoir types， and based on the test results of fluid production profiles of 112 sections of nine horizontal wells， it was concluded that the fracturing segments of I and II reservoirs account for 85.2%， and the output accounts for 96.4%， which was the main productivity contribution section. The fracturing segments of III reservoirs account for 14.8%， and the output accounts for only 3.6%， with the lowest contribution. Therefore， priority is given to fracturing type I and II reservoirs， and selective fracturing of III reservoirs. The main factors affecting productivity are reservoir length， fluid injection strength， fracture density， brittleness index， sand addition strength， permeability， discharge， porosity， horizontal stress difference and oil saturation. The material basis of reservoir is the first condition to obtain high productivity， and increasing the sweep volume of fracture net is an important way to maximize the productivity of unconventional oil and gas. The research results can provide a scientific basis for the optimal design of volume fracturing of shale oil horizontal wells and effectively promote the scale benefit development of shale oil.