涪陵页岩气田加密井轨道优化设计技术

Infill well 3D horizontal wellbore trajectory optimization design method in Fuling Shale Gas Field

为了进一步降低涪陵页岩气田加密调整井的施工难度,提高钻井速度,针对涪陵工区的地质特点,开展加密井轨道优化设计技术研究。页岩气三维轨道设计主要有五点六段制、斜面圆弧六段制、双二维等三种类型,本文通过定向段长、摩阻、扭矩等指标对比优选,得出斜面圆弧三维轨道设计更适合涪陵工区加密井轨道设计。为了优化斜面圆弧三维轨道设计参数,本文以一口三维水平井为例进行轨道优化,通过对比不同造斜点、造斜率情况下摩阻和扭矩的变化规律,以摩阻扭矩最小为优化目标,优选造斜点和造斜率,为涪陵页岩气田加密井轨道优化设计提供借鉴。

In order to further reduce the drilling difficulty of infill adjustment wells in the Fuling Shale Gas Field,as well as improve the drilling speed,research on infill well trajectories optimization design has been carried out in regard to the geological characteristics of the shale gas field.The 3D trajectory design for shale gas drilling mainly includes three types:“five-point six-section”trajectory,“six-section with the circular arc in the inclined plane”trajectory and“dual-2D”trajectory.The optimized“circular arc in the inclined plane”3D trajectory is determined to be more suitable for horizontal well design in the Fuling Shale Gas Field by comparison of the indicators such as the length of directional section,drag force,torque.To optimize the parameters of the 3D trajectory design with circular arc in the inclined plane,a case study has been conducted on trajectory optimization design for a 3D horizontal well with the kick off point and build-up rate optimized through comparison of drag force and torque at different kick off points and build-up rates to find out the minimum drag force and torque.It can provide reference for the infill well trajectory optimization design in the Fuling Shale Gas Field.