受压状态下水力压裂支撑剂性能评价方法  

Performance evaluating method of the hydraulic fracturing proppant under pressure

作　　者：徐启[1] 周晓峰 XU Qi;ZHOU Xiaofeng(No.10 Oil Production Plant of Daqing Oilfield Co Ltd, Daqing 163315,China;Unconventional Oil and Gas Research Institute, Northeast Petroleum University, Daqing 163318,China)

机构地区：[1]大庆油田有限责任公司第十采油厂,黑龙江大庆163315 [2]东北石油大学非常规油气研究院,黑龙江大庆163318

出　　处：《大庆石油地质与开发》2020年第5期51-57,共7页Petroleum Geology & Oilfield Development in Daqing

基　　金：“十二五”国家科技重大专项子课题“低渗透油气高效开发井完井优化设计与控制技术”(2011ZX05009-005)。

摘　　要：目前常用的水力压裂支撑剂室内评价方法常采用不锈钢代替岩样,利用位移传感器测量裂缝宽度,并基于无应力条件下计算出支撑剂孔隙度,所得出的室内实验结果不能真实反映支撑剂在井下环境的实际性能。针对上述问题,设计了一种新的水力压裂支撑剂性能评价实验仪器,制作了岩样裂缝模型,测试了3种常用水力压裂支撑剂(石英砂、树脂覆膜砂、陶粒)在不同压力条件下的孔隙度、破碎率以及岩样的裂缝宽度,采用内窥镜观察了支撑剂颗粒的破碎和嵌入现象。实验结果表明:随压力的增大裂缝宽度和支撑剂的孔隙度均呈逐渐降低的趋势,随铺砂浓度的增加水力压裂裂缝的宽度和孔隙度呈不断增加的趋势。40 MPa条件下,20/40目石英砂支撑剂的破碎率为24.6%;20/40目陶粒支撑剂的最大嵌入深度为0.17 mm。说明该方法能在受压状态下较好地完成水力压裂支撑剂的性能评价,评价结果可为压裂前支撑剂的选择提供参考。At present,the stainless steel is often used to replace the rock sample in laboratory evaluating method of the common hydraulic fracturing proppant.The displacing sensor is used to measure the fracture width,and the porosity of the proppant is calculated based on the stress-free condition.The achieved laboratory experimental results can not truly reflect the actual performances of the proppant in underground environment.In the light of the above problems,a new experimental instrument for evaluating the performances of the hydraulic fracturing proppant was designed,and the fracture model of the rock sample was made.The porosity,broken rate and sample fracture width of three commonly used hydraulic fracturing proppants(quartz sand,resin-coated sand and ceramsite)under different pressure conditions were tested.The broken and embedded phenomena of the proppant particles were observed by endoscope.The experimental results show that with the increase of the pressure,the fracture width and the proppant porosity decrease gradually,and moreover with the increase of the sand concentration,the width and porosity of the hydraulic fracture increase gradually.Under the pressure of 40 MPa,the broken rate of 20/40 mesh quartz sand proppant is 24.6%;the maximal embedment depth of 20/40 mesh ceramsite proppant is 0.17 mm.These results show that this method can be used to better evaluate the performances of the hydraulic fracturing proppant under pressure,and moreover the evaluated results can provide the reference for the selection of the proppant agent before the fracturing.

关 键 词：水力压裂 支撑剂 孔隙度 裂缝宽度 

分 类 号：TE357.12[石油与天然气工程—油气田开发工程]