水平井水力喷射压裂裂缝延伸规律研究

发布时间：2018-05-03 09:46

本文选题：水平井 + 水力喷射压裂　；参考：《西安石油大学》2015年硕士论文

【摘要】：低渗透油藏存在渗透率低、渗流阻力大、地层连通性差等特点，，导致常规开发方式效率很低甚至无效,而水力喷射压裂作为一种有效的低渗透储层改造方式,决定了低渗透油藏开发成功与否。目前我国水平井水力喷射压裂现场作业时,容易压穿地层,造成水平井井间联通,或者裂缝延伸不充分,往往导致压裂施工后没有形成有效的裂缝。其根本原因在于对水力喷射压裂作业时裂缝延伸规律没有一个总体的、全面的认识导致现场施工参数的设置不当,继而压裂失败。因此,对于水平井水力喷射压裂，给出一个全面的、统一的规律指导现场尤为重要。本文首先建立了水平井水力喷射压裂裂缝起裂模型，可计算得到裂缝延伸的起始压力和裂缝的初始延伸方向。其次,建立拟三维裂缝延伸模型,通过使用拟三维裂缝模模型拟系统,模拟了单裂缝延伸时,储层与盖层地应力差值、杨氏模量、断裂韧性、水力喷射射孔的数目和孔径、压裂液排量参数影响；结果表明：应力差值、射孔数目和排量与裂缝缝长和缝宽成正相关；弹性模量和断裂韧性与缝高成正相关；孔眼直径与裂缝延伸无相关性。然后,在多裂缝平面延伸模型下,通过模拟在不同簇数下,簇间距、压裂液粘度、泵排量、杨氏模量、地层厚度对裂缝延伸的影响。结果表明：簇间距和簇数是影响多裂缝延伸最主要因素：杨氏模量、地层厚度、压裂液粘度与最优簇间距成正相关；泵排量与最优簇间距成负相关；同时得到,一定的泵排量或者地层条件下，最优簇间距与地层厚度具体的数值比。最终这些规律可为现场水力喷射压裂裂缝的延伸预测和施工提供理论依据和指导。
[Abstract]:Low permeability reservoirs are characterized by low permeability, large seepage resistance and poor formation connectivity, which lead to low or even ineffective conventional development methods, while hydraulic jet fracturing is an effective low permeability reservoir reconstruction method. It determines the success of low permeability reservoir development. At present, hydraulic jet fracturing in horizontal wells in our country is easy to press through the formation, resulting in interconnection between horizontal wells, or insufficient fracture extension, which often leads to no effective fracture after fracturing operation. The fundamental reason lies in the fact that there is not a general understanding of the fracture extension law in hydraulic jet fracturing, which leads to improper setting of field operation parameters and subsequent fracturing failure. Therefore, it is very important to give a comprehensive and uniform rule for horizontal well hydraulic injection fracturing. In this paper, a fracture initiation model of hydraulic jet fracturing in horizontal wells is established, which can be used to calculate the initial pressure of fracture extension and the initial extension direction of fracture. Secondly, the pseudo-3D fracture extension model is established. By using the pseudo-3D fracture model simulation system, the in-situ stress difference between reservoir and caprock, Young's modulus, fracture toughness, the number and pore size of hydraulic jet perforation are simulated. The results show that stress difference, perforation number and displacement are positively correlated with fracture length and width, elastic modulus and fracture toughness are positively correlated with fracture height, and pore diameter has no correlation with fracture extension. Then, under the multi-fracture plane extension model, the effects of cluster spacing, fracturing fluid viscosity, pump displacement, Young's modulus and formation thickness on fracture extension are simulated under different cluster numbers. The results show that cluster spacing and cluster number are the main factors affecting the extension of multiple fractures: Young's modulus, formation thickness, fracturing fluid viscosity are positively correlated with the optimal cluster spacing, pump displacement is negatively correlated with the optimal cluster spacing, and at the same time, Under certain pump displacement or formation conditions, the optimal value ratio of cluster spacing to formation thickness is obtained. Finally, these laws can provide theoretical basis and guidance for the field fracturing fracture extension prediction and construction.
【学位授予单位】：西安石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE357.1

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