Jawaharlal Nehru Technological University Hyderabad B.Tech III WELL COMPLETION, TESTING AND SERVICING Previous Question Paper (August - 2022 - R18)

Well completion is the process of preparing a well for the production of oil or gas or for injection purposes. Its primary functions include:

• Zonal Isolation: Preventing fluid communication between different geological formations to avoid contamination or loss of production.
• Formation Protection: Ensuring the stability of the wellbore and preventing sand production or formation damage during fluid flow.
• Flow Control: Regulating the flow of reservoir fluids to the surface and enabling the ability to shut off production from specific zones if required.
• Artificial Lift Integration: Facilitating the installation of artificial lift systems (such as ESPs or gas lift) to sustain production rates as reservoir pressure declines.
• Monitoring and Surveillance: Providing access for downhole pressure and temperature measurements to evaluate reservoir performance.

The selection of a completion mode (e.g., open-hole, cased-hole, or gravel pack) and method depends on several technical and economic factors:

• Reservoir Characteristics: The permeability, porosity, and heterogeneity of the formation dictate the required flow capacity and potential for sand production.
• Fluid Properties: The viscosity, gas-oil ratio (GOR), and the presence of corrosive elements like H2S or CO2 influence the choice of materials and completion equipment.
• Well Geometry: The inclination (vertical, deviated, or horizontal) and depth of the well significantly impact the mechanical feasibility of specific completion strings.
• Economic Considerations: The expected production life of the well, capital expenditure (CAPEX) for equipment, and anticipated operational expenditure (OPEX) for future workovers must be balanced against projected revenue.
• Future Intervention Needs: The requirement for future stimulation (e.g., acidizing or fracturing) or the need to switch production zones necessitates a flexible completion design.
• Regulatory and Safety Requirements: Compliance with environmental standards and safety protocols regarding well integrity and pressure control is mandatory.