Well performance diagnosis and remedial strategies for production enhancement

Oil wells often experience production losses caused by excess water, scale, sand, organic deposition, emulsion effects, well-integrity problems, and artificial-lift limitations. These mechanisms may occur together, and a single diagnostic plot is rarely sufficient to identify the root cause. This manuscript presents an integrated field-diagnostic workflow for production-challenge diagnosis using production data, decline-curve behavior, water-oil-ratio trends, productivity comparison with offset wells, cased-hole logs, production logging, nodal analysis, and single-well predictive modelling. The workflow is developed to cover water sources, water-control diagnostics, coning remedies, emulsion-related electrical centrifugal pump (ESP) overload, scaling, sand production, paraffin wax, cement-bond-log interpretation, reservoir saturation tool (RST) and production logging tool PLT interpretation, and single-well performance forecasts. The excess water must first be classified as sweep water, good water, or bad water before any water-shutoff decision is made. Water oil ratio (WOR) behavior, production history, and PLT/RST evidence are then used to distinguish between coning, channel flow, watered-out layers, fractures or faults, and casing or cement communication. Flow-assurance analysis show that scale, sand, wax, and emulsion can produce similar symptoms, such as reduced productivity, high drawdown, ESP overload, and frequent workovers, but their required treatments are different. A predictive single-well model indicates that reducing formation damage from scale can increase the estimated productivity index from 0.57 to 0.91 STB/d/psi and increase one-year oil production by 58,554 STB, equivalent to a 61.8% improvement. The proposed workflow supports a structured diagnosis-to-action process and can help reduce trial-and-error interventions in mature oil wells.