重复压裂前诱导应力影响新裂缝转向规律

Study of fracture reorientation caused by induced stress before re-fracturing

 唐述凯¹ 李明忠¹ 綦民辉¹ 韩蕊² 李根³

中国石油大学（华东)石油工程学院，山东 青岛 266580 中国石化胜利油田分公司石油工程技术研究院，山东 东营 257000 振华石油控股有限公司，北京100031）

College of Petroleum Engineering, China University of Petroleum, Qingdao 266580, China Research Institute of Petroleum Engineering, Shengli Oilfield Company, SINOPEC, Dongying 257000, China China ZhenHua Oil Co. Ltd., Beijing 100031, China)

 With mature refracturing technology application, how to create a new fracture that has different orientation from the original fracture is becoming a hot issue in the current research of refracturing. As the direction of the new cracks is mainly controlled by the stress distribution near the wellbore, and the induced stress caused by the initial fractures, the production of oil wells and the influence of water injection are the main factors affecting the new fracture morphology. The finite element model of refracturing well was established by COMSOL, and the mechanism and influencing factors of fracture reoriented were analyzed. The water injection block model was established to study the distribution of water induced stress, and the influence of injection volume, injection and distribution network and other factors on fracture morphology. The results of simulation show that the fracture orientation is affected relatively large by the stress state of the reservoir, the oil well production and the initial crack length. Stress concentration will occur around the injection wells, and in a certain distance will affect the reorientation of the new fracture. This study can be applied to predict the refracturing effect, optimize the selection of wells, and guide the design of refracturing.

10.6056/dkyqt201704026