Coiled Tubing Best Practices in Conjunction with Multistage Completions in the Tight Gas Fields of Saudi Arabia

Abstract

Open hole multistage fracturing (MSF) completions are becoming standard practice in the south gas fields development in Saudi Arabia with more than 25 wells completed to date using open hole packers and selective port technology. Overall, the production results from the use of MSF completions have been very positive and the forecast is that MSF technology usage will grow considerably over the next several years. In general, MSF completions provide an excellent advantage in that they are intervention-less in their standard mode of operation. An aspect that is evolving is the secondary use of coiled tubing (CT) to handle the planned and unplanned (contingency) operations occasionally required to reach well production objectives. Without optimum operational planning and the selection of correct CT downhole tools, completion problems can be encountered and this ultimately can result in the job objective not being reached at all or only at increased costs. This paper presents MSF case studies where CT has been deployed and investigates the operational impact and productivity enhancement. Correlations taken from the key hardware variables, such as fracturing port size and type, motor type, mill bit type, and CT size, are also considered and analyzed. Following the lessons learned and best practices from these experiences, with correct implementation, the findings from this paper should increase the potential for successful multistage completion operations and ultimate improvements in productivity.