Well performance evaluation is a methodological approach used to systematically assess the operational efficiency and production behavior of oil and gas wells over their productive lifespan. This process integrates analysis of historical and current production data, often employing techniques such as decline curve analysis and incorporating relevant subsurface information from formation evaluation, to characterize well performance trends, diagnose production issues, forecast future performance, and support informed decision-making for optimization, intervention planning, and resource management throughout the well's lifecycle.