摘要：The Chang 7 shale oil reservoir in the Ordos Basin is typically characterized by multiple sandstone interlayers, which can restrict the vertical extension of hydraulic fractures across multilayered shale pay zones. An innovative radial borehole fracturing technique is proposed to enhance the fracture connectivity across multi-layered shale oil reservoirs. A field-scale 3D numerical model integrating logging data from the Chang 7 Member interlayered reservoir was developed to simulate radial borehole hydraulic fracturing. The fracture propagation behavior guided by multi-radial boreholes was systematically analyzed, and the effects of inter-radial borehole stress interference on stimulation performance were evaluated. An AutoML-based surrogate model was trained to optimize the radial borehole configurations in the stimulation of the multi-layered shale oil reservoir. The results indicate that compared to conventional stimulation with perforations, radial borehole fracturing enhances pay zone connectivity and overall stimulation performance, as evidenced by increases of 36.5 % in hydraulic fracture height and 11.6 % in stimulated area. Higher injection rates and fluid viscosities facilitate uniform fracture growth across multiple branches, as the injection fluid preferentially flows into branches with underdeveloped hydraulic fractures. Increased radial borehole spacing, length, and quantity promote fracture height growth; otherwise, intensified inter-cluster stress interference may occur, inhibiting uniform fracture extension. Radial boreholes with an inclination angle of 15 degrees effectively promote the vertical extension of hydraulic fractures across multiple layers, whereas excessive inclination angles tend to confine fracture propagation near the horizontal wellbore, resulting in reduced effective fracture height. The quantity of radial boreholes primarily influences fracture height, while radial borehole length is the dominant factor affecting stimulated area. To minimize the inter-cluster stress interference and achieve larger fracture heights at the Chang 7 Member interlayered shale oil reservoir, a 3-branch radial borehole layout with 12-15 m branch lengths, spacing ＞= 13 m, and inclination angles ＜= 20 degrees is preferred. The findings provide groundbreaking insights to enhance the efficiency of multi-layered shale reservoir stimulation.

关键字：Radial borehole fracturing; Multi-layered reservoir; Inter-cluster interference; Fracture geometry optimization; 3D discrete lattice

ISSN号：0013-7952

卷、期、页：卷359

影响因子：0.000000

期刊分区（SCI为中科院分区）：一区

收录情况：SCIE（科学引文索引网络版）,EI（工程索引）

发表期刊名称：ENGINEERING GEOLOGY

参与作者：胡乃琨,王小华

通讯作者：谢紫霄,龙腾达,潘涛,邹文超,孙照伟,孙耀耀

第一作者：武晓光,黄中伟,李根生,宋先知,杨睿月

论文类型：期刊论文

论文概要：谢紫霄,龙腾达,武晓光,黄中伟,李根生,宋先知,杨睿月,潘涛,邹文超,孙照伟,孙耀耀,胡乃琨,王小华，Radial borehole fracturing in the multilayered shale oil reservoir based on a 3D discrete lattice model，ENGINEERING GEOLOGY，，卷359

论文题目：Radial borehole fracturing in the multilayered shale oil reservoir based on a 3D discrete lattice model