Advancing Reservoir Evaluation: Field Application of Next-Generation Pulsed Neutron Tool with Diamond Detector for Enhanced Hydrocarbon Saturation Analysis

Abstract This study utilized a next-generation pulsed neutron tool equipped with innovative diamond detector to evaluate hydrocarbon saturation in multi-stacked reservoirs under challenging conditions. The tool's enhanced features include 50% increase in neutron generator output, high-resolution gamma-ray energy detection, and slim design for memory-mode logging in remote settings. Logging operations in Well A focused on the K sands, employing advanced processing algorithms like SATG for environment correction and data clarity. Despite operational constraints, the tool provided high-quality data, enabling comprehensive reservoir dynamics analysis and identifying untapped hydrocarbon potential. This paper details the application of a next-generation pulsed neutron tool with a diamond detector, designed for hydrocarbon saturation evaluation in complex, multi-layer reservoirs. The study, conducted on Well A, involved memory-mode logging with an 8-hour operational window due to remote logistical constraints. Key advancements, including a 50% increase in neutron output and enhanced gamma-ray detection, allowed precise measurements under challenging conditions. Data processing used SATG algorithm for environmental corrections, revealing reservoir depletion in the K1.0 sand and stable oil saturation in untapped layers. These methods provide actionable insights for optimizing mature field management. The study demonstrates the successful application of a next-generation pulsed neutron tool with a diamond detector, providing significant advancements in hydrocarbon saturation evaluation within complex, multi-stack reservoirs. Logging operations in Well A revealed key reservoir dynamics across the K sands. Results indicated a decrease in oil saturation in the producing K1.0 sand from 20% to 10%, consistent with depletion, alongside evidence of gas cap expansion. Meanwhile, the K5.5 and K7.0 sands maintained stable oil saturation levels of 20%, highlighting untapped reserves for potential future development. The advanced tool's enhanced capabilities, including a 50% increase in neutron generator output and high-resolution gamma-ray energy spectrum detection, enabled precise differentiation of hydrocarbon types and significantly improved data clarity, even in high-temperature environments. Despite operational challenges, such as restricted logging time and the absence of the GR-CCL sensor, the tool consistently delivered high-quality data, further refined by the SATG algorithm for environment corrections. In conclusion, the study underscores the tool's effectiveness in identifying subtle reservoir changes and optimizing mature field management strategies. These findings not only enhance decision-making for Well A but also establish a benchmark for advanced reservoir evaluation in similar challenging environments. This paper introduces a novel application of next-generation pulsed neutron tool with a diamond detector, showcasing advancements in hydrocarbon saturation evaluation under challenging reservoir conditions. By highlighting innovations such as enhanced neutron output, high-resolution gamma-ray detection, and the SATG algorithm for improved data clarity, it provides practicing engineers with actionable insights for optimizing reservoir management. The study's findings contribute valuable methodologies for addressing reservoir complexity and operational constraints in mature fields.