摘要
裂缝导流能力是反应压裂改造效果的重要指标。乌鲁木齐河东矿区具有大倾角、多厚煤层、低煤阶煤层气地质特征。为更好地指导乌鲁木齐河东矿区煤层气压裂施工,采用实验测试的方法,分别研究了时间、闭合压力、铺砂浓度、石英砂支撑剂粒径及组合对压裂改造中裂缝短期导流能力的影响。结果表明:不同铺砂浓度导流能力均随时间的增加而下降,前30min下降幅度较大,随着时间的增加导流能力降幅趋缓,75min导流能力平均下降幅度在65%~70%;不论是不同支撑剂粒径还是不同铺砂浓度,导流能力均随闭合压力增大而降低,但当闭合压力达到20MPa以后,闭合压力增加、导流能力下降趋势变缓;随铺砂浓度的提高,导流能力增大,7.5kg/m^(2)铺砂浓度为该区最小合理铺砂浓度;支撑剂粒径越大,导流能力越强,但也受闭合压力的影响,当闭合压力低于15MPa时,单一粒径16/30目的石英砂的导流能力远高于20/40目和40/70目的导流能力,而当闭合压力高于15MPa时,16/30目和20/40目各比例组合导流能力相差不大,但还是远高于40/70目支撑剂组合的导流能力。
The fracture flow capacity is an important indicator reflecting the effectiveness of hydraulic fracturing.CBM in the Hedong mining area of Urumqi has geological characteristics of high dip angle,multiple thick coal seams,and low coal rank.In order to better guide the construction of CBM fracturing in the Hedong mining area of Urumqi,the experimental testing methods were used to study the effects of time,closure pressure,sand concentration,quartz sand proppant particle size and combination on the short-term fracture flow capacity during fracturing.The results show that the flow capacity of different sand laying concentrations decreases with time,with a significant decrease in the first 30 minutes.The decrease in flow capacity slows down with time,with an average decrease of 65%~70%at 75 minutes;Whether it is different proppant particle sizes or different sand concentration,the diversion capacity decreases with the increase of closing pressure.However,when the closing pressure reaches 20MPa,the decreasing trend of the diversion capacity slows down as the closing pressure increases;As the sand concentration increases,the flow capacity increases,and the sand concentration of 7.5kg/m^(2) is the minimum reasonable sand concentration in this area;The larger the particle size of the proppant,the stronger the flow capacity,but it is also affected by the closing pressure.When the closing pressure is below 15 MPa,the flow capacity of a single 16/30 mesh quartz sand is much higher than that of 20/40 mesh and 40/70 mesh.However,when the closing pressure is above 15 MPa,the flow capacity of the 16/30 mesh and 20/40 mesh combinations is not significantly different,but still far higher than that of the combination containing 40/70 mesh proppant.
作者
胡永
周梓欣
仲劼
张伟
HU Yong;ZHOU Zixin;ZHONG Jie;ZHANG Wei(Xinjiang Yaxin CBM Investment and Development(Group)Co.,Ltd.,Urumqi,Xinjiang 830000;Xinjiang Coalfield Geology Bureau,Urumqi,Xinjiang 830000;Comprehensive Geological Exploration Team of Xinjiang Coalfield Geology Bureau,Urumqi,Xinjiang 830000)
出处
《中国煤炭地质》
2024年第6期27-32,57,共7页
Coal Geology of China
基金
“十三五”国家科技重大专项“新疆准噶尔、三塘湖盆地煤层气资源与开发技术”(2016ZX05043)。
