To reactivate wells that are not flowing, a common solution is to perforate any bypassed zone to bring the wells back to operation. If the completion does not allow for optimal interventions, i.e. running the perforating gun sized for the target interval, the consequences of a thru-tubing intervention must be evaluated based on cost, probability of success, risk and whether the potential results and the time savings of a rig are justifiable.
In a well in Minagish Field of Kuwait, a combination of thru-tubing technologies was deployed for perforating a bypassed zone, reducing the cost of a rig workover, and maximizing the potential results. The conveyance method was selected in consideration of well access, cost, provision of positive depth correlation, and the capability to deploy the perforating guns thru tubing. Second, the perforating system was modeled with the reservoir parameters for its impact on well productivity. After the perforation parameters were obtained, the application of post-perforating dynamic underbalance was proposed to clean the perforations and reduce skin. Downhole measurements while perforating was combined with all the runs, including gamma ray, collar locator, pressure, temperature. A fast gauge was run in memory mode with the post perforating underbalance guns.
The perforating operation was performed with a suite of measurements conveyed with digital slickline, enabling a cost-effective, informed intervention that reduced the operator's cost by USD 288,000 over a conventional rig-based operation. The combination of extra-deep penetrating shaped charges loaded a 2-1/8-in phased exposed carrier perforating guns system and the post-perforating cleanup system, restoring the well to a production of 1,500bbl/d.
The application of digital slickline that provided downhole measurement while perforating was deployed for the first time in Kuwait. The use of productivity modeling for perforating proved to be a successful metric for decision making when selecting this intervention methodology. This approach saved the operator time and cost while cutting risks and maximizing the potential production restoration.
