Unique Horizontal Water Shut-Off Experience in West Kuwait Integrating Surveillance & Digital Oilfield

Abstract

West Kuwait has produced oil since 1962 and has evolved into a mature carbonate-dominated producing region where water management is a critical element of base-production protection and reserves stewardship. The regional development philosophy favors non-commingled production, producing one reservoir layer at a time and applying a go-uphole strategy when the current interval no longer supports economic production. Water production, first observed in 1985, has progressively become a major operational and profitability challenge because it affects well deliverability, artificial-lift reliability, surface handling capacity, pressure behavior, and long-term reserves management. Approximately 30% of the well stock is drilled horizontally and contributes about 30% of regional oil production; approximately 75% of the horizontal well population remains active and is completed as barefoot, cased-hole, or inflow-control-device wells. This operating environment makes horizontal water shutoff a recurring field-development challenge rather than an isolated remedial activity. During the 2021–2025 water-conformance campaign, many horizontal-water-shutoff candidates matured for execution only when an artificial-lift malfunction, missing downhole measurements, ESP degradation, or workover accessibility created an operational window. Although such windows provide practical intervention opportunities, they also introduce a decision conflict: whether to rapidly access a new zone when the current interval is believed to have limited remaining economic potential, or to continue exploiting the existing interval by reducing unwanted water production. Bypassing surveillance can result in avoidable productivity loss, premature reserves debooking, and suboptimal workover selection. This paper therefore reframes horizontal water shutoff as a decision-assurance process rather than a remedial workover activity. The proposed approach is designed to reduce misdiagnosis by separating reservoir-driven water advancement from completion, trajectory, artificial-lift, and mechanical-integrity limitations before selecting same-layer water shutoff, operational control, mechanical or chemical isolation, ICD-related intervention, or zonal change. The proposed workflow is built on the West Kuwait Water Management Concept and integrates KwIDF, SAHALA, OFM, petrophysical interpretation, single-well-model review, geological mapping where available, and post-job evaluation. KwIDF provides PGOR, workover history, workover objectives, and workover programs; SAHALA provides well connections and wellbore schematics; OFM supports development surveys and water-case plots; and petrophysical review incorporates PLT, permeability, thickness, and correlated composite logs. The single-well model is used to identify skin damage and improve interpretation of water-advancement mechanisms. Production history remains the most continuously available diagnostic source and is analyzed using water-oil ratio and its derivative, WOR/WOR’, plotted against cumulative oil, operating days, or calendar time. These diagnostics are integrated with offset-well screening, trajectory analysis, water-case classification, decline-curve analysis, PLT, and downhole-temperature logs to distinguish three common West Kuwait water cases: channeling, conning, and water-table move-up. Two execution pathways are evaluated: same-layer water shutoff followed by production resumption from the existing interval, and water shutoff combined with zonal change through the go-uphole concept. Horizontal trajectory is central to this evaluation because deviation surveys commonly show lateral undulation, and campaign analysis indicates that high-water-cut horizontal wells may preferentially produce water from the lowest portions of the lateral. Where Y-tool access is available, PLT and caliper logs can be acquired to identify water-entry intervals and assess borehole integrity. Depending on casing-shoe location, completion type, and mechanical condition, plug placement, cement squeeze and reperforation, chemical or mechanical isolation, ICD-related isolation, bean-down, bean-up, or zonal change may be selected. Successful campaign cases delivered immediate oil-rate gains ranging from 130 to 4,700 BOPD, with an average gain of approximately 450 BOPD, and reduced average water cut from 80% to 53% in successful jobs. The campaign also demonstrates the cost of incomplete surveillance or poor alignment between the interpreted water case, the ideal remedy, and the executed solution. Documented outcomes include reduced productive capacity, unchanged productivity, limited incremental oil response, productivity decline, early reserves debooking, insufficient surveillance period, ICD or swell-packer failure, premature water-shutoff execution, and cases requiring pending PGORT follow-up. The main contribution of this paper is a structured decision-assurance workflow showing how KwIDF-assisted diagnostics, WOR/WOR’ behavior, trajectory review, completion understanding, surveillance maturity, remedy-to-mechanism matching, and campaign post-mortem evaluation can support the decision between same-layer water shutoff and zonal change while protecting base production and reducing the risk of premature reserves loss.