径向钻孔用自进旋转射流喷头数值模拟与实验研究

发布时间：2018-05-24 06:46

本文选题：径向钻孔喷头 + 水射流　；参考：《中国石油大学(华东)》2015年硕士论文

【摘要】：水力喷射径向钻孔技术是旨在提高油井产量的钻井新技术新方法。所谓水力喷射径向钻孔即是在一个储层平面通过喷射钻出多个沿直井半径方向的径向水平井眼,可大幅增加油井泄油面积,从而达到了“少井高产”、降低吨油成本的目的,是提高低渗透油气藏经济开采的重要手段。通过概述国内外研究现状,详解径向钻孔作业施工流程,分析国内外几种射流喷头的特点,为本课题的设计提供思路。从水射流理论出发,引入到本课题的研究重点CFD数值模拟分析,介绍CFD的研究方法和技术路线,使用CFD数值模拟分析优选喷嘴布置方式,喷头内腔流道形状、喷嘴出口段长径比的关键参数。确立了3个正向喷嘴、2个后向喷嘴的喷嘴布置方式,圆弧、圆锥混合型的内腔流道设计以及3.5~4.0的喷嘴出口段优选长径比。对喷嘴内外流场进行流场分析后得到个喷嘴的流量流速分布,发现初始设计的前向喷嘴直径过小,喷速较低,针对该问题修改模型后重新计算得到优选的喷嘴直径配置,前向喷嘴直径分别为0.6mm,0.7mm及0.8mm,反向喷嘴直径为1.2mm。计算得到在30L/Min的流量下,前向射流流量为11.89L/Min,后向喷嘴流量为18.11L/Min。利用ANSYS软件流固耦合模型对径向钻孔喷头破岩成孔过程进行分析,将流场分析结果导入结构力学分析软件,对破岩成孔过程进行数值模拟分析,验证喷头的冲蚀效果。结果显示,前向喷嘴射流作用在靶体上形成2层剪切破碎圈,形变范围大于喷头外径,这说明前向喷嘴在空间布置上是合理的;岩体所受最大剪应力为6.93MPa,对于硬砂岩抗压强度60.25MPa,按照岩石抗剪强度破坏理论,射流已能够破碎岩石。室内实验结果表明在40MPa的泵压,30L/Min的排量下喷头产生的水射流能够破岩,破岩形成的破碎坑的内切圆直径超过喷头外径,表明该设计方案用于破岩是有效的。
[Abstract]:Hydraulic injection radial drilling technology is a new drilling technology and new method aimed at increasing oil well production. The so-called hydraulic jet radial drilling is to drill several radial horizontal boreholes along the direction of the straight well radius in a reservoir plane, which can greatly increase the oil discharge area of the well, thus achieving the purpose of "less wells with high production" and reducing the cost of oil per ton. It is an important means to improve the economic exploitation of low permeability reservoirs. This paper summarizes the present research situation at home and abroad, explains the construction flow of radial drilling operation, and analyzes the characteristics of several kinds of jet sprinklers at home and abroad, which provides the train of thought for the design of this subject. Based on the theory of water jet, this paper introduces the CFD numerical simulation analysis, introduces the research method and technical route of CFD, uses CFD numerical simulation to analyze the optimal nozzle layout, the nozzle flow channel shape. Key parameters of nozzle exit length to diameter ratio. Three forward nozzles and two backward nozzles were set up, the design of the inner cavity flow channel of the arc and conical mixed type and the optimum aspect ratio of the nozzle outlet section of 3.5N 4.0 were established. After analyzing the flow field inside and outside the nozzle, the flow velocity distribution of the nozzle is obtained. It is found that the initial designed forward nozzle diameter is too small and the jet velocity is low. The diameter of the forward nozzle is 0.6 mm, 0.7 mm and 0.8 mm respectively, and the diameter of the reverse nozzle is 1.2 mm. Under the 30L/Min flow rate, the forward jet flow rate is 11.89L / min, and the backward nozzle flow rate is 18.11L / Min. The flow-solid coupling model of ANSYS software is used to analyze the process of rock breaking and forming hole of radial drill nozzle. The results of flow field analysis are imported into the structural mechanics analysis software, and the numerical simulation analysis of the process of rock breaking and hole formation is carried out to verify the erosion effect of the nozzle. The results show that the forward nozzle jet acts on the target to form two layers of shearing and breaking ring, and the deformation range is larger than the outer diameter of the nozzle, which indicates that the forward nozzle is reasonably arranged in space. The maximum shear stress of rock mass is 6.93 MPA. For the compressive strength of hard sandstone, 60.25 MPA, according to the failure theory of rock shear strength, the jet has been able to break the rock. The experimental results show that the water jet produced by the nozzle under the displacement of 30 L / Min of 40MPa pump pressure can break the rock, and the diameter of the inner tangent circle of the broken pit is larger than the diameter of the nozzle, which indicates that the design scheme is effective for rock breaking.
【学位授予单位】：中国石油大学(华东)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE921.1

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