Technology Update: New Instrumented Docking Gun System Maximizes Perforating Performance

Abstract

Technology Update Accidental detonation of a perforating gun at surface can have catastrophic consequences. To decrease risks, layers of procedural controls have been implemented to reduce the inadvertent application of power caused by human error, stray voltage, or the presence of radio frequency (RF) energy. Explosives handling procedures and controls, such as locking out the firing panel and acquisition system, are used to mitigate the human error risk. Mitigating RF risks requires establishing RF-free exclusion zones, with all RF transmissions shut down. Exclusion zones are effective, but adhering to them relies on strict procedural controls. With increased industry and personal reliance on RF transmitters, such as cellular phones, RF silence is becoming more difficult to achieve. Although RF-immune initiators were introduced more than 20 years ago to allow wellsite operations to continue without RF silence imposed, their complex initiation technologies require high power levels, which improve the safety margin to stray volt-age but significantly reduce overall system reliability. Perforating has always been a hands-on operation that relies on supervisor experience. Over the last decade, perforating reliability has continued to improve as service companies and operators have implemented detailed training programs, procedural checklists, and advanced hardware. However, these reliability improvements have begun to plateau, acting as an impetus to develop new perforating systems that would be more effective than procedural controls in addressing the main causes of perforating misruns: damaged or improper wiring, mechanical seal failures, and initiator malfunctions. Plug-In Design With Built-In Safety With a focus on resolving these issues, Schlumberger developed the Tempo instrumented docking perforating gun system—the industry’s first perforating system that fully integrates a plug-in gun with real-time advanced downhole measurements for monitoring and confirming operations to mitigate risk while increasing safety, reliability, and efficiency (Fig. 1). Created for all environments, the system uses modularized initiators combined with RF filtering mechanisms and an addressable switch to provide an enhanced level of safety to operations. Proprietary docking components are the key element of the gun system’s plug-in design. They streamline assembly and eliminate the major cause of perforating misfires: technique-sensitive crimping and wiring. The initiator can be plugged into a perforating gun by using simple mechanical and electrical connections without requiring complicated assembly. The new system eliminates all complex field wiring connections and crimping, which simplifies the arming process that has a direct impact on both wellsite efficiency and reliability.