Reserves, Behind Pipe

Test Your Knowledge

Quiz: Behind-the-Pipe Reserves

Instructions: Choose the best answer for each question.

1. What are behind-the-pipe reserves?

a) Reserves that are easily accessible and already being produced.

b) Reserves that are located in a new and unexplored area.

c) Reserves that are untapped within existing wells, requiring additional work to access.

d) Reserves that have been depleted and are no longer productive.

2. Which of these is NOT a common reason for behind-the-pipe reserves to remain untapped?

a) The well was only partially drilled through the reservoir.

b) The well completion was not optimized for accessing the reservoir.

c) The wellbore has become clogged or damaged.

d) The reservoir is completely depleted.

3. What is "re-completion" in the context of behind-the-pipe reserves?

a) The process of decommissioning an old well.

b) The process of drilling a new well in a different location.

c) The process of improving access to and production from untapped zones within existing wells.

d) The process of removing old casing from a well.

4. Which tool is NOT typically used for identifying and evaluating behind-the-pipe reserves?

a) Proximity logs

b) 3D seismic data

c) Satellite imagery

d) Advanced well logging techniques

5. What is a key benefit of targeting behind-the-pipe reserves?

a) Reduced reliance on fossil fuels.

b) Increased production from existing wells.

c) Reduced greenhouse gas emissions from drilling new wells.

d) Creation of new jobs in the oil and gas industry.

Exercise: Behind-the-Pipe Scenario

Scenario:

An oil and gas company has a well that was drilled in the 1980s. The well was only partially penetrated through the reservoir, and the completion design was not optimal for maximizing production. The company is considering re-completion to access behind-the-pipe reserves.

Task:

1. Identify at least two potential challenges the company might face during re-completion.
2. Suggest two technologies or techniques that could be used to overcome those challenges.
3. Explain how the chosen technologies or techniques could help achieve re-completion success.

**

This exercise encourages critical thinking about the challenges and solutions involved in unlocking behind-the-pipe reserves.

Techniques

Behind-the-Pipe: Unlocking Hidden Potential in Oil & Gas Wells

Chapter 1: Techniques

This chapter details the specific techniques employed to identify and extract behind-the-pipe reserves. These techniques span several disciplines, from reservoir characterization to well intervention.

Reservoir Characterization:

• Advanced Well Logging: This involves deploying a suite of logging tools (e.g., resistivity, porosity, nuclear magnetic resonance) to acquire detailed information about the reservoir properties beyond the initially completed interval. High-resolution logs and advanced interpretation techniques are crucial for identifying potentially productive zones missed during initial completion. This includes identifying permeability variations, fluid saturations, and fracture networks.

• 3D Seismic Interpretation: Sophisticated seismic imaging techniques can reveal subtle geological features and reservoir heterogeneity unseen by well logs alone. Analyzing seismic data allows for a better understanding of the reservoir's geometry and the extent of uncompleted zones within existing wells. Pre-stack depth migration and other advanced processing techniques enhance the accuracy of reservoir delineation.

• Production Logging: Production logging tools measure flow rates and pressure at various points within the wellbore. This data helps to pinpoint zones with restricted flow or areas contributing little to overall production, suggesting opportunities for recompletion to improve recovery.

Well Intervention Techniques:

• Sidetrack Drilling: In cases where the original wellbore is severely damaged or deviated far from the productive zone, sidetracking can create a new wellbore to access the behind-the-pipe reserves. This technique offers a more direct path to the target reservoir.

• Recompletion: This involves pulling out existing completion equipment, running new casing (if necessary) to isolate different zones, and installing new completion equipment designed to optimize production from the previously inaccessible zones. Techniques include selective perforating, setting new packers, and installing intelligent completion systems.

• Hydraulic Fracturing/Acidizing: Stimulation treatments are often necessary to improve reservoir permeability and enhance fluid flow to the wellbore. Hydraulic fracturing creates artificial fractures in the reservoir rock, while acidizing dissolves formation rock, improving conductivity. The type and design of stimulation treatment are tailored to the specific reservoir characteristics.

• Coil Tubing Operations: Coil tubing is used for a variety of interventions including running specialized tools to clean out blockages, perform perforating, or deploy stimulation treatments in a cost-effective manner.

Chapter 2: Models

Accurate reservoir modeling is essential for effective behind-the-pipe reserve assessment and planning. This chapter discusses the types of models used.

• Geological Models: These models incorporate geological data from various sources (well logs, seismic, core samples) to build a 3D representation of the reservoir. They are used to identify the geometry and extent of behind-the-pipe reserves. Geostatistical techniques are commonly used to handle uncertainty in data.

• Reservoir Simulation Models: These models simulate fluid flow within the reservoir under different operating conditions. They are used to predict the impact of recompletion strategies on production, estimate potential reserves, and optimize well management. Black-oil and compositional simulators are commonly used, depending on the complexity of the reservoir fluids.

• Economic Models: These models assess the economic viability of behind-the-pipe projects. Factors such as production forecasts, operating costs, and commodity prices are incorporated to determine the profitability of potential interventions. Sensitivity analysis is used to assess the impact of uncertainty on project economics.

Chapter 3: Software

Several software packages are used in the identification and exploitation of behind-the-pipe reserves.

• Well Log Interpretation Software: Software packages like Petrel, Kingdom, and Schlumberger’s Petrel are used to interpret well logs, identify potential zones, and integrate data from multiple sources. These packages allow for advanced interpretation techniques such as neural networks and geostatistical analysis.

• Seismic Interpretation Software: Software like Petrel, SeisSpace, and OpenWorks are used to process and interpret 3D seismic data, revealing reservoir architecture and identifying potential behind-the-pipe reserves. These packages allow for advanced processing techniques such as pre-stack depth migration and attribute analysis.

• Reservoir Simulation Software: Software like Eclipse, CMG, and INTERSECT are used to build and run reservoir simulation models. These packages allow for the prediction of production performance under different operating conditions and the optimization of recompletion strategies.

• Production Optimization Software: Dedicated software for production optimization assists in monitoring well performance, analyzing data, and identifying opportunities for improvement. This can include predictive modeling and AI-driven analytics.

Chapter 4: Best Practices

Successful exploitation of behind-the-pipe reserves relies on adherence to best practices.

• Comprehensive Data Acquisition and Integration: Accurate data acquisition and integration from multiple sources (well logs, seismic, production data) is crucial for a reliable assessment. Data quality control and validation are essential.

• Detailed Reservoir Characterization: A thorough understanding of the reservoir's geological properties, fluid properties, and flow dynamics is essential. This includes accurately modeling the reservoir's heterogeneity and complex geometry.

• Realistic Reservoir Simulation: Reservoir simulation should accurately reflect reservoir complexities and potential recompletion strategies. History matching ensures model reliability and predictive capability.

• Robust Economic Analysis: A comprehensive economic analysis is crucial to evaluate the profitability of behind-the-pipe projects. This should include sensitivity analysis to account for uncertainty in key parameters.

• Effective Project Management: Rigorous project planning and execution are vital for success. This includes clear communication, risk assessment, and efficient resource allocation.

Chapter 5: Case Studies

This chapter presents real-world examples of successful behind-the-pipe projects, illustrating the techniques, models, and software used and the resulting benefits. Each case study would detail:

• Project Overview: The specific well, reservoir characteristics, and initial production levels.
• Challenges and Opportunities: The specific challenges faced and the potential opportunities for improved production.
• Techniques Employed: The specific techniques used for reservoir characterization and well intervention.
• Results and Outcomes: The improvements in production, cost savings, and extended well life.
• Lessons Learned: Key lessons learned from the project that can be applied to future behind-the-pipe projects.

This framework allows for a comprehensive and structured exploration of the topic of behind-the-pipe reserves. Each chapter can be expanded upon with specific details and examples to create a comprehensive guide.