煤层气定向钻井智能水力控向机理研究

Intelligent directional drilling is the development tendency within the area of coal bed methane drilling in future. Based on the research results of the hydraulic correction theroy and technology, this project will focus on the action mechanism of intelligent hydraulic orientation drilling. .(1) This project will research the drilling depth detecting principle by using contactless electromagnetic induction method to digitize the drilling depth real time, thus providing the intelligent orientation algorithm with accurate drilling depth; .(2) Based on the automated hydraulic correction algorithm in section with a fixed drilling depth, this project will take into account the characteristic of various orientation drilling and properties of coal ahead to research the intelligent hydraulic orientation algorithm in section with a variational drilling depth real time; .(3) This project will introduce the advanced offline programming technology into the design and control of borepath to research the constrast algorithm and intelligent orientation algrithm on offline programming borepath control for directional drilling; .(4) This project will research the intelligent orientation algorithm for exploring the roof or baseboard of coal seam according to the data of rock properties offered by LWD (logging while drilling); and.(5) Based on all abovementioned research results, this project will further research the action mechanism for controlling the drilling parameters and hydraulic jetting parameters and then develop the software and hardware system for verifying this intelligent control..The research achievements will be used in a variety of directional drilling for coal bed methane, thus firstly realizing the intelligent orientation drilling in coal seam. This will be greatly instrumental to reduce the time and labor cost, decrease the accident frequency, and then improve the integrative competence for coal bed methane drilling and recovery.

智能控向钻进是未来煤层气钻井的发展趋势。本项目在水力纠偏的理论与技术研究基础之上，主要研究专用于煤层气钻井的智能水力控向作用机理，具体包括：研究非接触式双电磁感应钻进深度实时检测原理，实现定向钻进深度检测数字化，为后续智能控向算法提供精确的钻进深度计算依据；在现有区间法智能水力纠偏算法基础上，结合各种控向钻进工艺特征和钻遇煤岩特性，研究钻进深度实时变化的区间法智能水力控向算法；将先进的离线编程技术引入钻井轨迹的设计与控制，研究控向钻井离线编程轨迹控制对比算法及其智能控向算法；研究由随钻LWD提供的钻遇岩石特性数据进行煤层探顶或探底轨迹控制的智能控向算法；在以上研究基础上，研究调整钻进规程和水力射流参数的作用机理以及实现智能调控的软硬件验证系统。研究成果可指导煤层气的各类控向钻进，使煤田钻井能在控向钻井方面率先实现智能钻井，降低时间与劳动力成本，减小事故发生率，进一步提升煤层气钻采综合能力。

我国在煤层气勘探与开发方面已步入了国际煤层气产业的前列，但仍有许多煤层气钻井技术亟待完善或攻克，有必要针对煤层气开发的特点从定向钻井方面入手对其进行智能化研究，从而符合国际油气钻井技术向智能化钻井发展的总趋势。本项目依据原定研究基本内容，围绕项目研究关键问题，沿着项目研究技术路线，在项目组团体努力下，按研究年度计划开展研究。本项目首先针对煤层气近水平孔钻进变步长深度区间法智能控向算法中的实时钻进深度这一重要参数，在详细分析其工艺特点和难点的基础之上，提出了非接触式双电磁感应钻进深度随钻实时检测原理，实现了煤层气水平定向钻进深度的随钻实时数字化检测，既解决了倒杆导致钻进深度难以检测的难题，又为智能控向算法提供了轨迹计算与预测的重要依据；结合现有区间法智能水力纠偏算法，研究了实时变化的变步长钻进深度区间法智能控向算法，提高了智能控向算法的精度；根据定向钻进轨迹曲线的特性，引入离线编程相关理论与技术，研究了控向钻井离线编程在钻孔二维和三维轨迹控制中的对比算法及其智能控向算法，再依据随钻测井提供的钻遇岩石特性数据研究了煤层探顶或探底定向钻进轨迹控制的三维智能控向算法及其离线编程系统；在原有水力纠偏钻具的机械结构上，设计了一种新型的摆动式水力控向旋转导向钻具，主要是利用水力来推动钻头以球笼式万向节为回转中心摆动来实现控向的功能，克服了现有推靠式旋转导向钻井系统因需不断推靠井壁而造成严重的狗腿度问题和指向式旋转导向钻井系统因需不断压弯钻杆而使得钻杆受到很大的交变应力问题，并对其水力性能参数仿真；利用高压射流水泵和电磁阀，结合前述智能摆动式水力控向钻具的控制系统，搭建了水力射流智能控制实验平台，对水力控向钻具的孔底智能控制和地面的水力调控系统可行性进行了实验验证，为煤层气定向钻进智能化的进一步研究奠定了基础，其智能控向算法和调控机理也为水平螺旋钻进导向与激光定向钻进的智能化提供了参考。