二维阶梯形水平井段设计方法研究

阶梯形水平井段用于开发层叠状的多个油层,比用多口水平井来开发具有节省钻井投资、提高开采效率等优点.建立了阶梯形水平井段所满足的二元非线性方程组,对于常用的5种不同的未知数组合情况,使用数学化简技巧将该方程组归结为3种标准形式的三角函数方程组.推导出了3种标准形式方程组的解析解计算公式.在求解阶梯形水平井段设计问题时,增降斜井段的拐点处的井斜角是一个关键未知数,而油层井段的长度、增(降)井段的井眼曲率可以作为另一个未知数.以某水平井开发2个不同深度的薄油层为算例,对计算公式进行了验证,并与文献上的数据进行了对比,证实了计算公式的正确性.计算公式具有与具体未知数组合情况相对独立的特点,更有利于计算机软件开发时的模块化编程实现.

Well Trajectory Design in 2D Step-horizontal Hole Sections

Step-horizontal hole section is applied to stack-up muhi-reservoir exploitation,which has the advantage of saving drilling investment and enhancing recovery efficiency than multi-horizontal well exploitation.Binary nonlinear equation set for the step-horizontal hole sections is built.It may be transformed to trigonometric function equation set with three standard forms through mathematic simplified technique for common five conditions of unknown number array.Calculation formulas of analytic solution for these equation set with three standard forms are derived.During the well trajectory design parameter of the step-horizontal hole section is computed, hole deviation angle at breakpoint between build section and drop off interval is a key unknown number,and section length of reservoir and borehole curvature of the build section or drop off interval may he the other unknown number.Taking certain horizontal well for developing two thin reservoirs with different depth as exam- ple,the computing equation is verified and compared with the data on the references.Then it is proved right.It has the feature of relative independence with concrete unknown number array ,so it is favorable to module pro- gramming during computer software development.