Remedial Well Intervention Results in Production Increase in Deep High Rock-Strength Gas Well

Abstract

This paper presents the diagnosis and successful remediation of an underperforming gas well in a deep, high rock-strength formation. An integrated workflow combining downhole diagnostics, advanced well modelling, and perforation simulation identified the root cause of poor productivity and guided selection of specialized re-perforation system. The remedial intervention resulted in production increase, delivering incremental gas from a single well and established a technical basis for similar remedial applications in other wells. Identifying the root cause of poor well performance required an integrated diagnostic approach, including metal loss surveys (MIT), production logging (PLT), pressure transient analysis (PTA), and nodal analysis. Ineffective perforation and wellbore held up were identified as primary causes for high skin. Advanced perforation modelling was done using API Section I &Section II data to evaluate charge performance and select optimal gun system for re-perforation. Nodal analysis and PTA data were used to quantify skin, estimate effective perforation length, and predict potential gains. A structured operational decision tree was then developed to address operational risks before executing the re-perforation intervention. Diagnostic data acquired clearly indicated that the candidatewell's underperformance was primarily driven by ineffective perforation. MIT surveys confirmed incomplete casing penetration using maximum metal loss data. PLT data also established that production was mostly contributed from the middle reservoir, while the upper and lower reservoirs yielded minimal contribution due to ineffective perforation and debris fill which was obstructing flow from deeper zones. PTA further confirmed limited reservoir connectivity and high skin. Advanced perforation simulations demonstrated that conventional deep penetration charges were inadequate for this high-strength formation, necessitating the use of ultra-deep penetration charges. Executing theremedial program required meticulous planning to manage high pressures, significant inter-zone differential pressures, and a long perforation interval exceeding 1,000 ft. The re-perforation activity was successfully executed, and all the targeted intervals were re-perforated. Post-job results confirmed a increase in production, delivering the asset a high incremental gain. The results demonstrate the effectiveness of a data-driven diagnostic and design approach and establish a technical basis for implementing similar remedial strategies in other zones within the field and comparable wells. Documented field cases demonstrating data-driven productivity restoration in deep, high rock-strength gas wells through re-perforation is very limited. This paper presents a fully integrated case study combining downhole diagnostics, nodal analysis, and perforation simulation to identify and remediate productivity loss and incremental production gain. The workflows and operational insights described in this paper with provide engineers a practical, field-proven methodology to recover full production potential in challenging formations.