Which type of well is drilled after initial discovery to determine the size of the hydrocarbon deposit?

Which type of well is drilled after initial discovery to determine the size of the hydrocarbon deposit?

• A. Appraisal Well
• B. Exploratory Well
• C. Disposal Well
• D. Injection Well

Answer: (A)

After a discovery, the goal shifts to measuring how big the reservoir really is and how much oil or gas it can ultimately yield. This requires drilling appraisal wells within the discovered field to map its boundaries, determine thickness and extent, and gather detailed data on rock properties, pressures, fluids, and connectivity. The information from these wells feeds reserve estimates and helps shape the development plan, including spacing, completion strategies, and production forecasts. In contrast, exploratory wells are aimed at finding new accumulations in previously unproven areas, not sizing a known deposit. Disposal and injection wells are used to manage fluids—either disposing of waste fluids or injecting fluids for pressure maintenance and enhanced recovery—not to quantify the size of a hydrocarbon reservoir.

After a discovery, the goal shifts to measuring how big the reservoir really is and how much oil or gas it can ultimately yield. This requires drilling appraisal wells within the discovered field to map its boundaries, determine thickness and extent, and gather detailed data on rock properties, pressures, fluids, and connectivity. The information from these wells feeds reserve estimates and helps shape the development plan, including spacing, completion strategies, and production forecasts.

In contrast, exploratory wells are aimed at finding new accumulations in previously unproven areas, not sizing a known deposit. Disposal and injection wells are used to manage fluids—either disposing of waste fluids or injecting fluids for pressure maintenance and enhanced recovery—not to quantify the size of a hydrocarbon reservoir.