Window Exit Sidetrack Enhancements Through the use of Solid Expandable Casing
When most operators think of solid expandable casing, they primarily focus on their application as it relates to solving hole problems while minimizing any loss of hole size incurred by running a casing string. A new application for solid expandable casing quickly growing in popularity uses the tubulars to sidetrack through a milled window. Solid expandable casing can minimize, if not eliminate, many of the obstacles associated with sidetracking. The historic drawback of losing hole size through the window exit can be largely eliminated by using solid expandable casing. These tubulars enable the hole section to be drilled beyond the expandable casing with larger drill pipe and bottomhole assemblies (BHAs), including measure-whiledrilling (MWD) and logging-while-drilling (LWD) tools, which may have been impossible with a conventional sidetrack. Larger production tubulars and related completion equipment add to the value generated by using the solid expandable casing. This technique can also be instrumental in initiating slot recoveries that might not otherwise be economically viable. As with other applications of solid expandable casing, a successful installation requires proper pre-job planning. This paper reviews issues critical for success and also looks at specific examples of installations performed to date. Other technologies associated with expanding the solid casing will also be discussed in the context of wells already completed or in the planning stages. The economic benefits of this technique will also be explored.