摘要
为得到超短半径径向水平井开采煤层气过程中的气体渗流规律以及进行产量预测,在基本假设条件下,建立了径向水平井开采煤层气的固流耦合渗流数学模型;在一定的边界条件及初始条件下,利用Matlab软件进行编程计算后,得到直井和不同数目分支径向水平井开采煤层气1000天后的压力场、速度场和气产量变化规律。数值模拟结果表明,在一定的生产区域和开采时间,随着径向水平井分支数目的增加,煤储层压力下降范围更广,气体流速场干扰加强,压力漏斗降大面积扩展,煤层气有效供气区及解吸面积大幅增长,煤层气解吸能力及稳产能力加强,煤层气产量大幅度增加;同时,气产量增幅随着井筒分支数目的增加而下降,分支井数目理论上应存在一个最优值。模拟结果显示了超短半径径向水平井技术开采煤层气的有效卸压作用,对煤层气工业增产技术的选择和钻孔方案的布置具有重要的理论指导意义。
To derive the seepage rule and to make the productivity prediction of ultra-short radius radial horizontal well for coal-bed methane（CBM） exploitation,a fluid-solid coupling mathematical model was developed under the conditions of basic assumptions,a weak solution equation was formulated in certain boundary conditions and initial conditions and a set of program was developed with Matlab to show the variation of pressure field,velocity field and gas production in vertical shaft and radial-branch horizontal wells after 1000 days mining of CBM.The simulation results show that in certain production region and mining time,the scale of coal reservoir pressure drop is broadened,the disturbance of gas velocity field is strengthened,the area of pressure funnel drop is extended,the supply area and the desorption area of CBM grows largely,the desorption capacity and the stable production capacity are strengthened and the production increases substantially along with the increasing number of radial horizontal wells.Meanwhile, the growth rate of the gas production declines,thus there exists an optimum value for the number of radial horizontal wells.Effective pressure relief of ultra-short radius radial horizontal well in the CBM exploitation is shown in the simulation and it is significant to the choice of CBM industrial production increase technology and arrangement of drilling plan.
出处
《防灾减灾工程学报》
CSCD
2011年第1期50-55,62,共7页
Journal of Disaster Prevention and Mitigation Engineering
基金
国家自然科学基金项目(50674053)
辽宁省教育厅项目(05L167)
辽宁工程技术大学校青年基金项目(07-76)资助
关键词
超短半径径向水平井
煤层气
渗流规律
压力漏斗降
ultra-short radius radial horizontal well
coal-bed methane
seepage rule
pressure funnel
