Implementation of a Bottom-Hole Assembly Program

Abstract

A state of the art graphical user interface program has been developed to predict and design the bottom-hole assembly (BHA) performance for drilling. The techniques and algorithms developed in the program are based on those developed by Lubinski and Williamson. The BHA program facilitates conducting parametric studies and making field decisions for optimal BHA performance. The input parameters may include formation class, dip angle, hole size, drill collar size, number of stabilizers, and stabilizer spacing. The program takes into consideration bit-formation characteristics and interaction, drilling fluid weight, drill collar sizes, square collars, shock absorbers, measurement while drilling tools, reamer tools, directional tools, rotary steerable systems, etc. The output may consist of hole curvature (buildup or drop rate), hole angle, and weight on bit and is presented in drilling semantics. Additionally, the program can perform mechanical analyses and can solve for the bending moments and reaction forces. Moreover, the program has the capability to predict the wellpath using a drill ahead algorithm. The program consists of a mathematical model that makes assumptions of 2D, static, and constant hole curvature, resulting in a robust computationally efficient tool that produces rapid reliable results.