recompletion

Test Your Knowledge

Recompletion Quiz: Bringing Old Wells Back to Life

Instructions: Choose the best answer for each question.

1. What is the primary goal of recompletion? a) To permanently seal off an unproductive well. b) To drill a new well alongside an existing one. c) To enhance or restore the performance of an existing well. d) To explore for new oil and gas deposits.

2. Which of the following is NOT a reason for recompletion? a) Declining reservoir pressure. b) Production problems. c) Changing economic conditions. d) Discovering a new, untapped oil field.

3. What is a common workover operation performed during recompletion? a) Drilling a new wellbore. b) Replacing the entire wellhead. c) Hydraulic fracturing. d) Building a new oil platform.

4. What is a significant benefit of recompletion? a) Increased reliance on drilling new wells. b) Reduced environmental impact compared to drilling new wells. c) Complete elimination of production problems. d) Always achieving higher production rates than initial completion.

5. What is a key challenge associated with recompletion projects? a) Always being more expensive than drilling new wells. b) Lack of technology to address production issues. c) Finding enough skilled workers to perform the work. d) Thorough risk assessment and cost management.

Recompletion Exercise

Scenario: An oil well has experienced declining production due to formation damage.

Task: Outline a potential recompletion strategy to address this issue and improve production. Be sure to consider:

• Workover operations: What specific techniques could be used to address formation damage?
• Completion design: Would any modifications to the completion design be necessary?
• Expected outcomes: What are the potential benefits and challenges of this recompletion approach?

Techniques

Recompletion: A Comprehensive Guide

Chapter 1: Techniques

Recompletion techniques encompass a wide range of procedures aimed at restoring or enhancing well productivity. The specific techniques employed depend on the well's condition, reservoir characteristics, and the recompletion objectives. Key techniques include:

1.1 Well Re-entry: This initial step involves carefully accessing the wellbore. Methods include using coiled tubing, wireline, or workover rigs. The process might involve milling, fishing (retrieving dropped equipment), and cleaning the wellbore to prepare for subsequent operations. Precise navigation and control are crucial to prevent damage to the existing completion.

1.2 Stimulation Techniques: These aim to improve reservoir permeability and increase fluid flow. Common methods include:

• Hydraulic Fracturing: High-pressure fluids are injected to create fractures in the reservoir rock, increasing the surface area for fluid flow. This is particularly effective in low-permeability formations.
• Acidizing: Corrosive acids are injected to dissolve formation materials, improving permeability and enhancing flow paths. Different acid types are used depending on the reservoir rock composition.
• Matrix Stimulation: This involves improving the permeability of the near-wellbore formation without creating large-scale fractures.

1.3 Sand Control: Sand production can severely damage equipment and reduce well productivity. Sand control methods aim to prevent sand from entering the wellbore, including:

• Gravel Packing: A layer of gravel is placed around the wellbore to prevent sand migration.
• Screens: Metal or synthetic screens filter out sand while allowing fluids to flow.
• Sand Consolidation: Chemicals are injected to bind sand particles together, strengthening the formation.

1.4 Tubing and Casing Repair: Damage to the tubing or casing can compromise well integrity and production. Repair techniques involve:

• Cementing: Repairing leaks or weak areas in the casing by injecting cement.
• Replacing Damaged Sections: Removing and replacing damaged sections of tubing or casing.
• Running new tubing strings.

1.5 Completion Modifications: This involves modifying the existing completion design, such as:

• Installing or replacing packers: These isolate different zones in the wellbore to allow selective production.
• Installing new perforations: Creating new openings in the casing to access different reservoir zones.
• Implementing new inflow control devices (ICDs): Managing production from multiple zones.

Chapter 2: Models

Accurate reservoir and wellbore modeling is crucial for successful recompletion planning. Models help predict the outcome of different recompletion strategies and optimize well performance. Key modeling aspects include:

• Reservoir Simulation: These models predict fluid flow and pressure changes in the reservoir, helping to estimate the potential production increase from recompletion.
• Wellbore Simulation: These models simulate fluid flow within the wellbore, considering factors like friction, pressure drop, and multiphase flow.
• Fracture Modeling: For hydraulic fracturing, these models predict the extent and geometry of fractures, influencing the effectiveness of stimulation.
• Data Integration: Integrating data from various sources, including well logs, production history, and core analysis, improves model accuracy.

Chapter 3: Software

Specialized software plays a critical role in planning, executing, and analyzing recompletion projects. Examples include:

• Reservoir Simulation Software: Commercial packages like Eclipse, CMG, and Petrel provide tools for reservoir modeling, history matching, and forecasting.
• Wellbore Simulation Software: Software packages like OLGA and Pipesim simulate multiphase flow in wellbores.
• Fracture Modeling Software: Specialized software predicts fracture geometry and propagation during hydraulic fracturing.
• Data Management Software: Software packages allow efficient storage, retrieval, and analysis of well data.

Chapter 4: Best Practices

Effective recompletion requires adherence to best practices to ensure safety, efficiency, and optimal results:

• Thorough Pre-Job Planning: Detailed planning, including risk assessment, cost estimation, and selection of appropriate techniques, is essential.
• Accurate Data Acquisition and Analysis: High-quality data from well logs, production history, and core analysis are vital for informed decision-making.
• Proper Equipment Selection and Maintenance: Using appropriate equipment and ensuring its proper maintenance is crucial for safety and efficiency.
• Rigorous Safety Procedures: Adhering to strict safety protocols throughout the recompletion process is paramount.
• Environmental Protection: Implementing measures to minimize environmental impact is essential.
• Post-Job Evaluation: Analyzing the results of the recompletion to assess its effectiveness and identify areas for improvement.

Chapter 5: Case Studies

Successful recompletion projects demonstrate the effectiveness of various techniques and the importance of best practices. Case studies can showcase examples of:

• Improved Production Rates: Illustrating significant increases in production following recompletion.
• Extended Well Life: Highlighting successful projects that significantly extended the productive life of wells.
• Cost-Effective Solutions: Demonstrating how recompletion provided a more economically viable alternative to drilling new wells.
• Challenges Overcome: Showing how innovative techniques and problem-solving skills addressed specific challenges encountered during recompletion. This could involve overcoming unusual geological conditions or equipment failure. (Specific case studies would be included here, each with detailed descriptions of the well, the challenges, the techniques used, and the results.)