Well Completions | Introduction

Summary

This video introduces the concept of oil and gas well completions, focusing on the technology and techniques used to produce hydrocarbons efficiently and safely. It outlines the well completion process, including the design, installation, and control of equipment to manage production. The video discusses key reservoir drive mechanisms like dissolved gas drive, gas cap drive, and water drive, and emphasizes the importance of optimized completion designs for maximizing recoverable reserves. The video also highlights factors that influence well performance, such as reservoir properties and completion systems, while stressing the need for careful planning and execution in modern well completions.

Takeaways

• 😀 Well completions are essential for properly completing a well after drilling, ensuring it can be put into production.
• 😀 The well completion process involves the design, selection, and installation of tubulars, tools, and equipment within the wellbore.
• 😀 The purpose of well completions is to efficiently convey, pump, or control the production fluids from the reservoir to the surface.
• 😀 There are three basic requirements for a completion system: efficiency, safety, and economy.
• 😀 A poor completion design can jeopardize long-term goals such as maximizing recoverable reserves, especially as a reservoir depletes.
• 😀 Reservoir drive mechanisms, such as dissolved gas drive, gas cap drive, and water drive, impact production efficiency.
• 😀 Dissolved gas drive involves the release of dissolved gas under pressure, which helps push fluid towards the wellbore.
• 😀 Gas cap drive uses the expansion of gas at the top of the reservoir to maintain production pressure and drive oil towards the well.
• 😀 Water drive relies on water from surrounding formations to help sweep hydrocarbons toward the well, typically enhanced by water injection.
• 😀 Modern multiple completions are often more complex to ensure high flexibility and control over production from different zones of the reservoir.
• 😀 Factors affecting well performance include reservoir boundaries, reservoir properties, and the completion design itself, which is the only controllable factor.

Q & A

What is the definition of a well completion in oil and gas production?

A well completion refers to the methodology and technology required to produce recoverable reserves from a reservoir to the surface. It involves the design, selection, and installation of tubulars, tools, and equipment in the wellbore to convey, pump, or control production fluids.

What are the main requirements of a completion system?

The completion system must provide an efficient, safe, and economical way of producing petroleum products. Emphasis on economic factors may increase, but a non-optimized completion can jeopardize long-term objectives, such as maximizing recoverable reserves.

How do reservoir drive mechanisms influence well completions?

Reservoir drive mechanisms, such as dissolved gas drive, gas cap drive, and water drive, determine how hydrocarbons are produced. Well completion designs must be adapted to these mechanisms to ensure efficient production, as the energy stored within the reservoir is used to bring hydrocarbons to the surface.

What is the dissolved gas drive mechanism?

In a dissolved gas drive reservoir, oil contains dissolved gas. As production reduces pressure, the gas escapes from solution, forcing fluid towards the wellbore. The expansion of gas in the wellbore further encourages drawdown and oil production.

What is a gas cap drive and how does it work?

A gas cap drive occurs when excess gas rises to the top of the reservoir and forms a cap over the oil. As production takes place, the expansion of the gas cap maintains pressure, which helps to push the oil toward the wellbore, improving production efficiency.

How does the water drive mechanism work in a reservoir?

Water drive occurs when water in surrounding formations expands and moves toward low points in the reservoir, creating a sweeping force that helps push hydrocarbons towards the production well. This mechanism is highly efficient, allowing up to 85% of recoverable oil to be produced.

What role does water injection play in maintaining water drive reservoirs?

Water injection is used to maintain pressure in water drive reservoirs, ensuring efficient production of hydrocarbons by supplementing the natural water movement within the reservoir.

Why are modern multiple completions more complex?

Modern multiple completions are more complex because they require greater flexibility and control over the production or injection of individual zones within a reservoir. This allows operators to optimize production and manage different reservoir characteristics more effectively.

What are the factors that affect well performance?

Well performance is influenced by several factors, including reservoir boundary, reservoir properties, and the completion system. Since the completion system is the only factor that can be directly controlled, it is crucial for its design and installation to be carefully managed.

What is the potential risk of using a non-optimized completion system?

A non-optimized completion system may lead to inefficiencies in production and can compromise long-term objectives, such as maximizing recoverable reserves. Poorly designed completions can result in early depletion or suboptimal recovery from the reservoir.