First Field Application in Kuwait of an Electric Sub Release Tool for E-Line Coiled Tubing Perforation in HPHT Wells

Abstract

The North Kuwait Jurassic Gas (NKJG) reservoir is a mature high-pressure/high-temperature (HPHT) gas asset characterized by a highly corrosive production environment, with H2S and CO2 concentrations exceeding conventional coiled tubing (CT) operating thresholds. Plug-and-perf (PnP) stimulation remains the preferred completion strategy for effective reservoir development. However, extended deviated sections and high well inclinations restrict the reach of conventional wireline systems, requiring CT-conveyed E-line for perforation depth accessibility. Historically, these assemblies utilized mechanical shear-pin-based disconnect systems with limited overpull capacity. During gun detonation, axial shock and vibration transmitted through the Bottom-hole Assembly (BHA) frequently exceeded shear-pin limits, resulting in unintended releases. This led to multiple Lost-in-Hole (LIH) incidents, increasing operational risk, fishing requirements, and intervention complexity. To address this systemic failure mechanism, a revised disconnect philosophy was introduced through the first successful implementation of Electric Sub Release (ESR) technology in Kuwait. The ESR system replaces passive mechanical shear components with an electronically actuated release mechanism that activates only upon receipt of a controlled surface electrical signal. By eliminating dependence on mechanical shear limits under dynamic loading, the system mitigates unintended release risks associated with shock and vibration during perforation. Field deployment of the ESR tool demonstrated stable performance under HPHT and high-sour conditions. The system maintained structural integrity during gun detonation events, preventing premature disconnect and ensuring uninterrupted perforation execution. Operational reliability was restored, allowing CT-conveyed perforation activities to proceed with improved confidence in high-deviation Jurassic wells. Following implementation, multiple perforation campaigns were completed without disconnect-related LIH incidents. The removal of shear-pin-induced failures significantly reduced operational exposure and non-productive time. Based on consistent field performance, ESR technology was formally adopted as the standard disconnect mechanism and mandated for all CT-conveyed E-line perforation operations in the NKJG field. This transition establishes a new reliability benchmark for perforation systems operating in HPHT, highly deviated, and corrosive gas environments in Kuwait