Developmental Research on Cutting a Notch in Deep Borehole for Hydraulic Fracturing with High Speed Waterjets

高速水射流深孔水力压裂切槽开发研究

基本信息

批准号：
62850111
负责人：
MATSUKI Koji
金额：
$ 2.18万
依托单位：
TOHOKU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Developmental Scientific Research
财政年份：
1987
资助国家：
日本
起止时间：
1987 至 1988
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-62850111/
关键词：
Rock Hydraulic fracturing Artificial slit High speed waterjets High water pressure 溝切削

项目摘要

In order to clarify the applicability of high speed waterjets technology to making a slit in deep borehole for hydraulic fracturing, the testing apparatus was manufactured first to simulate the slot cutting of rock in deep water up to 2000m and then, the effects of various cutting parameters such as driving pressure, standoff distance, nozzle diameter and traverse rate on the depth of cut, the slot width and the specific energy were investigated for Shirakawa welded tuff using the driving pressure up to 100 MPa and flow rate of 80 1/min.The main results obtained in this study are summarized as follows;1) Although the depth of cut rapidly decreases with circumferential water pressure, if finally becomes almost constant at about 10 MPa of water pressure. Maximum depth of cut was 32.2 mm under water pressure of 20 MPa for Shirakawa welded tuff.2) Main cutting mechanism is cavitation errosion for the smaller cavitation number less than 0.05, and for larger cavitation number other mechamisms predominate.3) Empirical formulae on the depth of cut were proposed for both regions where the depth of cut depends on circumferential water pressure and where it is independent of water pressure.4) It is found that there exists an optimum water pressure and optimum standoff distance from the view point of energy consumption.5) The width of slot rapidly increases with water pressure until it reaches almost constant value.6) High speed waterjets can be applied to making a slit in deep borehole for hydraulic fracturing.

为了明确高速水射流技术在深孔切缝水力压裂的适用性，首先制作了试验装置，模拟深水2000m的岩石切缝，然后研究了各种切割参数的影响。使用高达 100 MPa 的驱动压力和流量，研究了白河焊接凝灰岩的驱动压力、间隔距离、喷嘴直径和移动速度等对切割深度、槽宽和比能量的影响速率为80 1/min。本研究获得的主要结果总结如下：1）虽然切削深度随着周向水压迅速减小，但最终在水压约10 MPa时几乎保持恒定。白河熔结凝灰岩在 20 MPa 水压下的最大切削深度为 32.2 mm。 2）对于小于 0.05 的较小空化数，主要切削机制是空化侵蚀，对于较大空化数，则以其他机制为主。 3）针对切削深度取决于周向水压和与水压无关的两个区域，提出了切削深度。4）发现从能量消耗的角度来看，存在一个最佳水压和最佳间隔距离。5) 槽缝宽度随着水压迅速增加，直至达到几乎恒定的值。6) 高速水射流可用于在用于水力压裂的深钻孔。