Application of minimum curvature method to wellpath calculations

Thesis Overview

<p> </p><p><strong>FORMULATION OF THE PROBLEM</strong></p><p><strong>1.1 Introduction</strong></p><p>Directional drilling is the science and art of deviating a wellbore along a planned course to a subsurface target whose location is a given lateral distance and direction from the vertical (Bourgoyne et al, 1991). Directional drilling and horizontal wells represent an efficient way to achieve or hitting special targets that may or are very difficult to reach using vertical wells (Tarek, 2000). Directional drilling is relatively done to increase production rates, control water and gas conning, control sand production and increase recovery rate (Bourgoyne et al, 1991). There are many reservoirs which can not be tapped by vertical wells or would be uneconomical to exploit with vertical wells (Bourgoyne et al, 1991). Other reservoirs are also characterized by vertical permeability or the pay zones may be very thin and producing with vertical wells would require quiet a number of them which would make vertical wells to be very uneconomical in such situations. The application of vertical wells in such formations could also result in lower ultimate recovery (Tarek, 2000). In such low permeability formations, the only way out is to use directional and horizontal well technology which has over the years proved to enhance ultimate recovery (Bourgoyne et al, 1991). Due to the more economical nature of directional and horizontal wells over vertical wells in most cases, they are mostly the preferred technology in offshore drilling technology (Bourgoyne et al, 1991).</p><p><strong>1.2 Problem Definition</strong></p><p>A major drawback of directional and horizontal well drilling is the numerous complex computations required to be done ahead of time before drilling resumes and also during drilling operations (Sawaryn, 2005). These computations become very stressful and more complex when done manually. The programs available in the market used for these computations are usually very expensive to acquire, but the development of a user-friendly Excel Spreadsheet program which employs the Minimum Curvature method for wellpath planning would help minimize the stress and time in executing these complex computations. More importantly, an Excel Spreadsheet program is very flexible and can easily be modified or updated at any point in time to meet the needs of the industry.</p><p>This study seeks to use the Minimum Curvature Method to design well path using Excel Spreadsheet to determine the optimum well path parameters. This would help reduce risks and uncertainty or prevent deviation from target, minimise non-productive time and reduce drilling cost. This would therefore enhance planning process and maximizing return on investment.</p><p><strong>1.3 Objectives of Study</strong></p><p>The objectives of this study are:</p><p>1. &nbsp; &nbsp; &nbsp;To develop a user friendly Excel Spreadsheet program that will make the computations of well trajectory parameters easier, faster and accurate.</p><p>2. &nbsp; &nbsp; &nbsp;Use the Excel Spreadsheet program to evaluate and compare some of the survey calculation method available for the industry.</p> <br><p></p>