Oil and gas field studies comprise a host of activities related to the development of oil and natural gas resources. These involve an initial screening study of the field, the culmination of which identifies, recommends and prioritizes potential target reservoirs for further study and possible development. Once favorable candidates are identified, prospective recoveries in a select base case is estimated and associated cash flows are prepared. Taking into account availability of drilling rigs and workover equipment, forecast scenario cases comprise optimal development plans, detailed tables for individual wells, potential recompletion candidates, infill or extension drilling-including directional wells- water injection or tertiary recovery in respect to operating constraints. Relying on these information, field-development life cycles and operational strategies to maximize rates of return and minimize overdevelopment are recommended.