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

Abstract This paper documents the results of a new stage of development in the application of coiled tubing drilling. Combining coiled tubing drilling 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, except for running liners, with the coiled tubing drilling rig was avoided. A conventional workover rig was the preferred approach to prepare the coiled-tubing-candidate well when it required a change out 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. Although it appears very obvious and straightforward to combine two established technologies, there are many challenges to overcome. Specialized equipment, multidisciplinary personnel, and control of overall well cost are just a few of the many parts of the operation that had to be planned. This paper details the results, problems encountered, solutions, and a quantification of the real benefits achieved combining coiled tubing drilling with a jointed pipe workover.