These wells are often drilled after a discovery and are used to determine the size of the hydrocarbon deposit.

• A. Exploration Well
• B. Appraisal Well
• C. Development Well
• D. Production Well

Answer: (B)

Appraisal wells are drilled after a discovery to delineate the reservoir and determine its size, extent, thickness, and heterogeneity. They collect essential data on pressures, fluids, and rock properties to refine the geological model and provide a reliable reserves estimate. This information is crucial for planning how the field will be developed—how many wells are needed, where they should be placed, and what production strategies to use.

Exploration wells search for new accumulations, development wells focus on preparing and expanding production within a known field, and production wells are the actual producers.