Trajectory Control: Directional MWD Inversely New Wellbore Positioning Accuracy Prediction Method

作     者：Ahmed Abd Alaziz Ibrahim Tagwa Ahmed Musa 

作者机构：Faculty of Engineering China University of Geosciences Wuhan 430074 China Engineering Faculty Sudan University of Science and Technology Sudan Faculty of Earth Resources China University of Geosciences Wuhan 430074 China Engineering Faculty Sudan University of Science and Technology Sudan 

出 版 物：《Journal of China University of Geosciences》 (中国地质大学学报（英文版）)

年 卷 期：2004年第15卷第4期

页      面：425-433页

核心收录：

学科分类：081801[工学-矿产普查与勘探] 08[工学] 0818[工学-地质资源与地质工程] 

主　　题：wellbore trajectory bit trajectory actual/planned path steerable directional tool measurement while drilling (MWD) logging while drilling (LWD) position uncertainty error accuracy prediction weighting function 

摘      要：The deviation control of directional drilling is essentially the controlling of two angles of the wellbore actually drilled, namely, the inclination and azimuth. In directional drilling the bit trajectory never coincides exactly with the planned path, which is usually a plane curve with straight, building, holding, and dropping sections in succession. The drilling direction is of course dependant on the direction of the resultant forces acting on the bit and it is quite a tough job to hit the optimum target at the hole bottom as required. The traditional passive methods for correcting the drilling path have not met the demand to improve the techniques of deviation control. A method for combining wellbore surveys to obtain a composite, more accurate well position relies on accepting the position of the well from the most accurate survey instrument used in a given section of the wellbore. The error in each position measurement is the sum of many independent root sources of error effects. The relationship between surveys and other influential factors is considered, along with an analysis of different points of view. The collaborative work describes, establishes a common starting point of wellbore position uncertainty model, definition of what constitutes an error model, mathematics of position uncertainty calculation and an error model for basic directional service.