分支井设计中开窗点的计算方法

在煤层气开发中,一般采用多分支、鱼骨型的井眼轨道.在分支井设计中,在完成主井眼轨道设计之后,需要根据地质上给定的开窗点数据在设计轨道上确定相应的设计开窗点井深及井身数据.教科书和有关文献上没有计算开窗点的现成公式,为了开发分支井轨道设计软件的需要,建立了从地质开窗点数据计算设计开窗点井深的优化矢量数学模型;根据稳斜井段和圆弧井段的矢量数学模型,推导出了设计开窗点的井深计算公式,给出了从设计轨道数据计算设计开窗点的算法.经过对某国内油田数十口分支井实际设计数据的检验,本文给出的设计开窗点计算公式和算法具有计算速度快、计算结果准确、容易编程实现等优点.本文的计算公式和算法可用于分支井轨道设计计算机软件的开发编程.

Computing Method of Window-Point for Lateral Well Design

Multi-lateral and herringbone well track usually appear in the development of the coal-bed gas.Af- ter trajectory design of original hole is completed in the lateral well design,corresponding well depth and wellbore data may be determined on the designed trajectory according to the given window-point data on ge- ology.There are no equations of calculating the window-point on the textbook or related references.In order to develop trajectory design software of the lateral well,optimized vector mathematical model of calculating well depth is built according to the data of geological window-point.Based on the vector mathematical models of angle-maintain intervals and arc intervals,calculating equation for well depth at the designed window-point is derived and the designed window point may be calculated according to the designed trajectory data.After ac- tual designed data of dozens of lateral wells in certain oilfield in China are tested ,computing method of win- dow-point in this paper has the advantages of fast calculation,accurate result and being easy to programming realization.So the equation and method of it may be applied to development programming of the computer software for the trajectory design in the lateral well.