多分支缝水力压裂近井筒起裂机制研究

发布时间：2018-05-04 21:43

本文选题：多分支缝 + 水力压裂　；参考：《特种油气藏》2017年01期

【摘要】：针对多分支缝水力压裂井筒起裂效果差的问题,基于弹性力学理论,考虑初次压裂诱导应力对近井地带应力场的作用,建立多分支缝起裂角及起裂压力的力学计算模型。在此模型的基础上,计算并分析了多分支缝起裂角的影响因素和多分支缝的延伸情况。研究结果表明:在低水平应力差及高闭合应力条件下,形成分支缝的起裂角越大,分支缝水力压裂效果越好;在低水平应力差,初始裂缝缝长越短的条件下,分支缝偏转程度高,更易重新定向。根据力学模型计算7口井分支缝的起裂压力,并对比现场施工起裂压力,验证了模型的准确性。该研究成果为多分支缝水力压裂工艺提供了理论基础,对优化分支缝压裂施工具有一定的指导意义。
[Abstract]:In order to solve the problem of poor fracture initiation effect in hydraulic fracturing wellbore with multi-branched fractures, based on the theory of elastic mechanics, considering the effect of initial fracturing induced stress on the stress field in the near well zone, a mechanical calculation model for fracture initiation angle and pressure of multi-branched fractures is established. On the basis of this model, the factors affecting the initiation angle of multi-branch joints and the extension of multi-branched joints are calculated and analyzed. The results show that under the condition of low horizontal stress difference and high closure stress, the greater the fracture angle is, the better the hydraulic fracturing effect of the branched fracture is, and the shorter the initial fracture length is, the lower the horizontal stress difference is. The branch seam deflection degree is high, easier to redirect. According to the mechanical model, the fracture initiation pressure of seven branched fractures is calculated, and the accuracy of the model is verified by comparing the field construction initiation pressure. The research results provide a theoretical basis for the hydraulic fracturing process of multi-branched fractures and have a certain guiding significance for optimizing fracturing operation of branched fractures.
【作者单位】：东北石油大学;中国石油大庆油田有限责任公司;
【基金】：黑龙江省普通高等学校骨干教师创新能力资助计划“深部裂缝性凝灰岩层水力劈裂机理的分形研究”(1254G002)
【分类号】：TE357.1

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