CAJ | 학술논문

煤层气开采过程中通常采用数值模拟方法进行生产指标预测，其中的数值模型普遍采用三维全隐式差分法求解，模型涉及的参数变量多，求解难度大，计算复杂。根据煤层气的储气特征、吸附特征和解吸机理建立了反映煤层气解吸、扩散及渗流过程的气、水两相流动煤层气羽状水平井三维数学模型，模型考虑了煤层非均质各向异性的影响，运用块中心差分格式，对气、水相偏微分方程进行空间差分和时间差分，采用交替隐式（ADI）法求解，实现了煤层气羽状水平井开发数值模拟计算。交替方向格式可以把二维问题转化成一维问题，对x，y两个方向的迭代矩阵均为三对角矩阵，结构相同，易于编程计算。所建立的差分格式具有计算量小，稳定性好等优点，数值试验的结果表明效果良好。
매층기개채과정중통상채용수치모의방법진행생산지표예측，기중적수치모형보편채용삼유전은식차분법구해，모형섭급적삼수변량다，구해난도대，계산복잡。근거매층기적저기특정、흡부특정화해흡궤리건립료반영매층기해흡、확산급삼류과정적기、수량상류동매층기우상수평정삼유수학모형，모형고필료매층비균질각향이성적영향，운용괴중심차분격식，대기、수상편미분방정진행공간차분화시간차분，채용교체은식（ADI）법구해，실현료매층기우상수평정개발수치모의계산。교체방향격식가이파이유문제전화성일유문제，대x，y량개방향적질대구진균위삼대각구진，결구상동，역우편정계산。소건립적차분격식구유계산량소，은정성호등우점，수치시험적결과표명효과량호。
The numerical simulation is an effective method to confirm CBM exploitation scheme and evaluate recovery factor. Present widely used 3D full implicit difference method is hard to compute and get solution. According to CBM storage and adsorption character-istics, as well as desorption mechanisms have modeled gas, water two phases flow CBM pinnate horizontal well 3D mathematical model can reflect CBM desorption, diffusion and seepage processes. The model has considered impacts from anisotropic coal seams, using block-centered finite difference scheme carried out spatial and temporal differences on gas, water phases partial differential equation, through ADI to get solution, realized CBM pinnate horizontal well exploitation numerical simulation computing. The alternating direc-tion scheme can transform two-dimensional problem into one-dimensional problem, to x, y two direction iterative matrixes are all tri-diagonal matrixes with same configuration, thus easy to programming computation. The difference scheme established has advantages of small computation amount and good stability;the results of numerical experimentation have shown good effect.