Relative permeability modifier and sealant gel treatments for effective water shutoff and sustainable hydrocarbon recovery in carbonate reservoirs

Title : Relative permeability modifier and sealant gel treatments for effective water shutoff and sustainable hydrocarbon recovery in carbonate reservoirs

Abstract:

This paper presents a study on water shutoff in carbonate reservoirs to enhance hydrocarbon recovery and mitigate excessive water production. With increasing water cut in the ageing fields of the Western Offshore, sustaining hydrocarbon production has become a critical challenge. Candidate wells exhibit an average water cut of 85%, necessitating effective water shutoff interventions. To understand the mechanisms of water incursion, wells were analyzed using Formation Evaluation Reports (FER), production history, well cards, Chan plots, Production Logging Tool (PLT) studies, and well logs, including cement logs, resistivity, and neutron porosity logs. The primary reservoirs are characterized by a thin, saturated oil column of approximately 20m, sandwiched between an overlying gas cap and an underlying aquifer with a 5m transition zone. These geological features contribute to early-stage water conning. The decline in oil production is primarily attributed to rising oil-water contact (OWC) and water channeling, leading to watered-out completions. To address these challenges, laboratory studies were conducted to develop effective sealant gel and optimize chemical compositions for mitigating water coning. Additionally, a Relative Permeability Modifier (RPM)-based Eco-gel was formulated to control water from channels and fractures. Experimental results indicate that low molecular weight and low-degree hydrolysis partially hydrolyzed polyacrylamide (PHPA) is suitable for gel formation, providing adequate gelation time for optimal placement in the formation.

This paper presents a comprehensive approach that includes problem analysis, selection of appropriate water shutoff chemical formulations to mitigate excessive water production, a core flow study, and the resulting findings aimed at enhancing hydrocarbon production from carbonate reservoirs

Keywords: Water Shutoff, Gel treatment (RPM), Core  flow, Production enhancement.

Biography:

Haji Mastan Tippuluri is currently working as a Well Completion, Stimulation, and Water & Gas Shut-Off Engineer at the Institute of Production Engineering and Ocean Technology (IPEOT), ONGC, Mumbai. With over eight years of experience, he has specialized in well interventions, completion design, and chemical treatment formulations for managing water shut-off in sandstone and carbonate reservoirs. Previously, he served as a Well Engineer at ONGC's Cauvery Asset, where he was responsible for designing and executing workover programs that addressed tubing failures, packer milling, fishing operations, sand production, and formation damage. His technical expertise spans acid stimulation, chemical water shut-off, loss control gels, and coal fines mitigation.

He has led several research efforts related to commingled production, inflow control devices, and smart well technologies. Academically, he holds an M.Tech in Chemical Engineering from IIT Kharagpur and a B.Tech from JNTU Anantapur. His research work has been published in Ultrasonic Sonochemistry (Elsevier), and he has also presented technical papers at national-level symposiums. Haji Mastan is IWCF-certified in Well Intervention Pressure Control and is proficient in simulation tools like WELLCAT and PIPESIM. As an active member of the Society of Petroleum Engineers (SPE), he maintains a strong interest in developing innovative completion and WGSO solutions to enhance hydrocarbon recovery. Outside his professional life, he pursues interests such as badminton, yoga, and volunteering for social causes.