通用下部钻具三维小挠度静力分析的数学模型及应用  

A METHEMATICAL MODEL FOR 3D ANALYSIS OF GENERAL BOTTOMHOLE ASSEMBLY UNDER SMALL DEFLECTION AND ITS APPLICATION

作　　者：李子丰[1] 赵新瑞[2] 赵德云[2] 

机构地区：[1]中国地质大学石油与天然气工程系,武汉430074 [2]大庆石油管理局钻井所,大庆163413

出　　处：《工程力学》2000年第6期121-129,共9页Engineering Mechanics

摘　　要：随着钻井技术的进步，以控制井眼轨道为目的的下部钻具组合发展迅速。在原来的普通增斜、降斜和稳斜钻具的基础上，发展了多种类型的导向钻具、带偏心弯接头的防斜钻具、带柔性接头防斜钻具和两稳定器间变刚度的增斜钻具等多种新型下部钻具组合。为了更好地应用这些新钻具,建立了适用于对普通下部钻具、导向钻具、带偏心弯接头和柔性接头的下部钻具进行三维小挠度静力学分析的数学模型，包括(1)微分方程，(2)钻头、稳定器、弯角、变截面、切点和井壁的边界条件，(3)钻头的侧向力和钻头转角。用该理论编写了应用软件。作为软件的部分功能,对几套钻具进行了增斜率随井斜角变化的预测, 并进行了初步分析。With the progress of drilling technology, bottom hole assembly (BHA) has been developed rapidly to control well trajectory. Many new type of BHA such as steering motor assembly, dropping assembly with eccentric bend sub, dropping assembly with flexible joint have been developed upon common building, dropping and holding assemblies. A mathematical model is established which includes (1) differential equations; (2) boundary conditions at drill bit, stabilizer, bend angle, diameter change, tangent point and borehole wall; (3) lateral forces and deflection angles of bit. This model can work with common BHA, steering down hole motor assembly, BHA with off center bend and flexible joint. Under the small deflection assumption, the weighted residual method is employed to obtain the three-dimensional solution of the governing equations. The variations of building rates with the inclination of several BHAs are predicted and analyzed.

关 键 词：下部钻具 导向钻具 数学模型 钻柱力学 柔性接头 三维小挠度静力分析 

分 类 号：P634.42[天文地球—地质矿产勘探]