存在部分连通断层的线性复合油藏井底压力动态研究

针对存在部分连通断层的线性复合油藏研究较少,用现有的试井解释模型对具有部分连通断层边界的油藏试井资料进行解释所得到的结果不理想的现状,本文引入界面表皮概念,将部分连通断层视为一个无限薄的表皮边界,建立了两区无限大线性复合油藏中存在部分连通断层的试井解释模型,并利用Fourier指数变换和Laplace变换等方法进行求解,绘制了井底压力响应特征曲线,并用实例对模型进行验证。分析表明,界面表皮越大,曲线上翘越多,当它足够大时,表现为封闭断层的特征;厚度比、流度比越大,曲线表现出定压边界的特征;导压系数比越小,Ⅱ区的储集能力越大,相应的压力及压力导数曲线位置越靠下。

Analysis of transient pressure behavior in linear composite reservoir with partially connected faults

The application of presently existing models of well testing analysis to actual well testing data with partially connected fault boundary usually resulted in unsatisfactory consequences.Therefore,a concept of "boundary skin" is proposed in which the partially connected fault is considered as an infinite thin boundary skin and a new well testing model for partially connected fault in a two-zone,linear composite reservoir is established.Fourier and Laplace transformations are used to calculate and obtain the solution,and to plot the responding typical curves of well bottom pressure.It shows that large boundary skin leads to the upward of curve.When the boundary skin is large enough,the partially connected fault is characteristic of close fault.If the ratio of thickness and ratio of mobility become larger,the typical curve demonstrates a character of stable pressure boundary.It reveals that the smaller the pressure coefficient ratio,the greater the storage capacity of the zone Ⅱ,and the lower the corresponding pressure and pressure derivative curve position.