大庆致密油藏水平井重复压裂及裂缝参数优化模拟

Refracturing and fracture parameters optimization simulation for horizontal well in Daqing tight oil reservoir

任佳伟 王贤君 张先敏 王维

中国石油大学（华东）石油工程学院，山东 青岛 266580 非常规油气开发教育部重点实验室（中国石油大学（华东）），山东 青岛 266580 中国石油大庆油田有限责任公司采油工程研究院，黑龙江 大庆 163000 黑龙江省油气藏增产增注重点实验室，黑龙江 大庆 163000

大庆致密油藏部分水平井压裂投产后产能递减严重，初次增产措施失效，油藏整体采出程度低。为寻求低产水平井有效增产方法，开展了重复压裂技术综合研究。文中利用数值模拟方法建立了重复压裂产能预测模型及水平井压裂裂缝应力场计算模型，分析了目标井重复压裂的增产潜力，明确了重复压裂改造的有利区域，优选了重复压裂最佳改造方式，进而确定了最佳改造方式下的最优裂缝参数组合。模拟结果表明：重复压裂措施可有效扩大储层改造体积和补充地层能量，显著提高单井产量；老缝增能、新缝压裂是大庆致密油藏重复压裂最佳改造方式，裂缝补压簇数及裂缝导流能力对大庆致密油重复压裂影响效果显著，裂缝半长对产油水平影响有限。

After some fractured horizontal wells in Daqing tight oil reservoir are put into production, the production capacity declines seriously and the initial production stimulation measures fail, thus the overall recovery degree of the reservoir is low. In order to find effective production stimulation methods for low-production horizontal wells, comprehensive research on refracturing technology is carried out. By using the numerical simulation method, the refracturing productivity prediction model and the fracture stress field calculation model of horizontal well are established to analyze the target well′s refracturing stimulation potential, determine the favorable area of refracturing, optimize the best refracturing mode, and then determine the optimal fracture parameters combination under the best stimulation mode. The stimulation results show that refracturing measures can effectively expand the reservoir stimulation volume, supplement formation energy and significantly increase single well production. Enhancing old fractures and fracturing new fractures is the best way of refracturing in Daqing tight oil reservoirs. The clusters number of added-fractures and fracture conductivity have a significant effect on refracturing in Daqing tight oil reservoirs, and the effect of fracture half-length for oil production level is limited.

10.6056/dkyqt202005018