地面压裂井衰竭期井下接替抽采时空衔接关系研究  

Research on temporal-spatial relationship between ground fracturing wells and underground drilling for substitution drainage of during extraction exhaustion period

作　　者：李阳 舒龙勇[1,2] 凡永鹏 郝晋伟[1,2] 周建伟 何健 LI Yang;SHU Longyong;FAN Yongpeng;HAO Jinwei;ZHOU Jianwei;HE Jian(China Coal Research Institute,Beijing 100013,China;State Key Laboratory of Coal Mining and Clean Utilization,China Coal Research Institute,Beijing 100013,China;Gas Control Research Center,Shanxi Lu'an Yuwu Coal Industry Co.,Ltd.,Changzhi 046000,China;Lu'an Chemical Group Co.,Ltd,Changzhi 046000,China)

机构地区：[1]煤炭科学技术研究院有限公司,北京100013 [2]煤炭科学研究总院煤炭资源高效开采与洁净利用国家重点实验室,北京100013 [3]山西潞安集团余吾煤业有限责任公司瓦斯治理研究中心,山西长治046100 [4]潞安化工集团有限公司,山西长治046100

出　　处：《煤炭科学技术》2022年第12期73-82,共10页Coal Science and Technology

基　　金：国家科技重大专项资助项目(2016ZX05067006-003);国家自然科学基金面上资助项目(51874178);煤炭科学技术研究院有限公司技术创新基金资助项目(2021(X-I-07))。

摘　　要：为了利用地面压裂形成的有利抽采条件进行地面压裂井衰竭期井下钻孔接替抽采,形成“地面压裂井超前治理+井下钻孔接替抽采”的井上下接替抽采模式,开展了地面压裂井衰竭期井下接替抽采的合理时空衔接关系研究。通过地面压裂井压裂裂缝展布规律分析、地面压裂增透促抽效果井下考察及煤储层参数变化规律数值模拟等工作,掌握了潞安矿区地面压裂井的影响作用及有效影响范围,采用数值模拟方法分析确定了井下接替钻孔与地面压裂井的最优空间布置关系;基于地面压裂井排采曲线,并结合衰竭期井下钻孔接替抽采的需求,探讨了地面压裂井衰竭期的定义和划分方法,提出了地面压裂井衰竭期的判别指标及关键时间节点。研究结果表明:潞安矿区地面压裂井的有效影响范围为井周80 m,在该区域内储层压力可以下降50%左右,透气性系数可以增加0.77~1.40倍,井下接替钻孔单孔抽采纯量平均值可达53.68~131.67 m^(3)/d,提升了井下钻孔的抽采效率;当地面压裂井沿钻孔轴向上的位置固定时,则井下接替钻孔与地面压裂井的法向距离越短,抽采效果越好,当地面压裂井与接替钻孔的法向距离不变时,地面压裂井位于接替钻孔轴向中部位置时井下接替钻孔的抽采效果最好;将地面压裂井的产气速率作为衰竭期评判指标,潞安矿区地面压裂井衰竭期的判别指标临界值为产气速率200 m^(3)/d,对应的衰竭期时间节点为8~10 a。In order to make use of the favorable extraction conditions formed by ground fracturing to carry out the underground borehole replacement extraction in the drainage exhaustion period of ground fracturing wells, and form the advanced treatment of ground fracturing wells + underground borehole replacement extraction mode of underground borehole replacement extraction, the temporal-spatial relationship between ground fracturing wells and underground drilling for substitution extraction of during drainage exhaustion period was studied. Through the analysis of the distribution law of fracturing fractures, the investigation of the effect of ground fracturing on enhancing permeability and promoting extraction, and the numerical simulation of the variation law of coal reservoir parameters, the influence and effective range of ground fracturing wells in Lu ’an Mining Area are mastered. Numerical simulation method is used to analyze and determine the optimal temporal-spatial relationship between ground fracturing wells and underground drilling for substitution extraction.Based on the drainage curve of surface fractured wells and the demand of drilling in the drainage exhaustion period, the definition and division method of the drainage exhaustion period of surface fractured wells are discussed, and the discriminant indexes and key time nodes of the drainage exhaustion period of surface fractured wells are put forward. The results show : The effective influence range of ground fracturing wells is 80 m. In this area, the reservoir pressure can be decreased by about 50%, the permeability coefficient can be increased by 0.77-1.40 times, and the average pure volume of single underground drilling for substitution extraction can reach 53.68-131.67 m^(3)/d,which improves the extraction efficiency of downhole drilling. When the position of ground fracturing wells is fixed along the axis of the underground drilling, the shorter the normal distance between the underground drilling and the ground fracturing wells, the better the ext

关 键 词：地面压裂井 衰竭期 井下接替抽采 时空衔接关系 产气速率 

分 类 号：TD712.6[矿业工程—矿井通风与安全]