True Hybrid Operations Combining Coiled-Tubing Drilling and Conventional Rig Workover Techniques and Practices

摘要

This paper documents the results of a new stage of development in the application of coiled-tubing drilling (CTD). Combining CTD technology with a conventional jointed-pipe workover capability represents the next-step change in providing low-cost reserves access solutions through selection of the most efficient tool for the application. Drilling sidetracks using coiled tubing is an established practice in Alaska's North Slope oil fields. During these operations, the use of jointed pipe was avoided, except for running liners, with the CTD rig. A conventional workover rig was the preferred approach to prepare the coiled-tubing candidate well when it required a changeout of production tubing or other workover activity. In 2001, a North Slope operator evaluated the opportunity to utilize one rig to perform both operations. In 2002, a workover rig was modified to fit the need. Integrating two established technologies presented many challenges. Specialized equipment, multidisciplinary personnel, and control of overall well cost are just a few of the many parts of the operation to be planned. This paper details the results, problems encountered, solutions, and a quantification of the real benefits achieved combining CTD with a jointed pipe workover.