Drilling & Well Completion

Partial Completion

Partial Completion: A Targeted Approach to Well Stimulation

In the realm of oil and gas production, maximizing reservoir access and optimizing fluid flow is paramount. Partial Completion, a technique employed in well stimulation, plays a crucial role in achieving these goals.

What is Partial Completion?

Partial Completion refers to a well completion strategy where only a portion of the pay zone is perforated and accessed. This is in contrast to a full completion, where the entire pay zone is open to production.

Why Use Partial Completion?

Partial Completion is a powerful tool used to address specific challenges during well stimulation, namely:

  • Coning Control: In reservoirs with differing fluid densities, lighter fluids (like gas or oil) tend to migrate upwards, forming a "cone" above heavier fluids (like water). Partial Completion can help manage this coning by selectively accessing specific sections of the reservoir, preventing excessive production of lighter fluids and ensuring a more stable flow.
  • Fracture Origin Selection: In hydraulic fracturing operations, the location of the initial fracture can significantly impact the effectiveness of the stimulation. By partially completing the well, operators can control the fracture initiation point, directing the fracture growth towards the most productive areas of the reservoir.
  • Enhanced Production: In certain cases, partial completion can actually increase production rates by:
    • Optimizing fluid flow: Targeting specific zones can improve fluid flow paths, maximizing production from the most productive portions of the reservoir.
    • Reducing pressure drawdown: Partial completion can minimize the pressure drop in the wellbore, leading to more efficient production.
  • Managing Reservoir Heterogeneity: In reservoirs with varied rock properties, partial completion allows operators to selectively access the most productive zones, maximizing production while minimizing the risk of premature water breakthrough.

Types of Partial Completion

Several techniques are used to achieve partial completion, including:

  • Selective Perforation: This involves perforating only specific sections of the wellbore casing, allowing access to chosen zones.
  • Plugging and Perforating: This technique uses plugs to isolate sections of the pay zone, followed by perforation in the desired areas.
  • Multi-Zone Completions: This involves creating multiple completion intervals within the wellbore, allowing independent control of fluid production from different sections of the reservoir.

Advantages of Partial Completion:

  • Improved Production: Increased production rates and efficient reservoir access.
  • Enhanced Reservoir Management: Control over fluid flow patterns and coning.
  • Cost-Effective: Targeted stimulation can optimize resource allocation and minimize expenses.
  • Reduced Risk: Selective completion minimizes the risk of premature water breakthrough and maximizes well performance.

Conclusion:

Partial Completion offers a targeted approach to well stimulation, allowing operators to optimize production, manage reservoir complexities, and maximize the long-term value of their assets. By selectively accessing specific zones within the pay zone, partial completion provides a powerful tool for enhancing production and achieving sustainable oil and gas recovery.


Test Your Knowledge

Quiz: Partial Completion in Well Stimulation

Instructions: Choose the best answer for each question.

1. What is the main difference between partial completion and full completion?

a) Partial completion uses only one perforation, while full completion uses multiple. b) Partial completion accesses only a portion of the pay zone, while full completion accesses the entire zone. c) Partial completion is used for gas wells, while full completion is used for oil wells. d) Partial completion is more expensive than full completion.

Answer

b) Partial completion accesses only a portion of the pay zone, while full completion accesses the entire zone.

2. Which of the following is NOT a benefit of using partial completion?

a) Improved production rates b) Enhanced reservoir management c) Reduced risk of water breakthrough d) Increased drilling costs

Answer

d) Increased drilling costs

3. How can partial completion help manage coning?

a) By isolating the water zone from the oil zone b) By increasing the pressure in the wellbore c) By selectively accessing specific sections of the reservoir d) By preventing the formation of fractures

Answer

c) By selectively accessing specific sections of the reservoir

4. Which of the following is a technique used for partial completion?

a) Horizontal drilling b) Hydraulic fracturing c) Plugging and perforating d) Acidizing

Answer

c) Plugging and perforating

5. What is the main goal of partial completion?

a) To maximize production rates b) To minimize drilling costs c) To prevent reservoir depletion d) To reduce environmental impact

Answer

a) To maximize production rates

Exercise: Partial Completion Strategy

Scenario:

You are a well engineer working on a new oil well in a reservoir with significant vertical heterogeneity. The top portion of the reservoir contains high-quality oil, while the bottom portion contains water. You need to design a partial completion strategy to maximize oil production and minimize water breakthrough.

Task:

  1. Identify the specific challenges: What are the main challenges posed by the reservoir heterogeneity?
  2. Propose a partial completion technique: Which technique would be most suitable for this scenario?
  3. Explain your reasoning: Justify your choice of technique and how it addresses the identified challenges.
  4. Potential benefits: What are the expected benefits of implementing this partial completion strategy?

Exercise Correction

**1. Challenges:** - The reservoir's heterogeneity makes it difficult to access the high-quality oil zone without also producing water. - Water coning is a likely issue, with water potentially migrating upwards and diluting the produced oil. **2. Proposed Technique:** - Plugging and perforating. **3. Reasoning:** - Plugging and perforating allows for precise control over the intervals accessed in the reservoir. - Plugs can be used to isolate the water zone at the bottom, preventing it from entering the wellbore. - Perforations can be strategically placed in the high-quality oil zone, maximizing oil production. **4. Benefits:** - Maximized oil production by targeting the most productive zone. - Minimized water breakthrough, reducing the need for water handling and maintaining oil quality. - Improved reservoir management by allowing for selective access and control over fluid production.


Books

  • Petroleum Engineering Handbook by Tarek Ahmed (Comprehensive resource covering well completion techniques, including partial completion.)
  • Reservoir Stimulation by A.S. Grader (Explores various stimulation methods, with a dedicated chapter on partial completion and its applications.)
  • Well Completion Design and Operations by J.C. Donaldson (Provides detailed insights into well completion design, including selective perforation and multi-zone completions.)

Articles

  • "Optimizing Production in Heterogeneous Reservoirs through Partial Completion" by J.P. Smith and T.M. Jones (Published in SPE Journal, discusses the benefits of partial completion in heterogeneous reservoirs.)
  • "Partial Completion for Gas-Coning Control in Tight Gas Sands" by A.K. Sharma and R.L. Thompson (Focuses on the application of partial completion for gas coning control in tight gas reservoirs.)
  • "Economic Evaluation of Partial Completion in Offshore Oil Wells" by D.M. Lee and S.J. Kim (Analyzes the economic viability of partial completion in offshore oil wells.)

Online Resources

  • Society of Petroleum Engineers (SPE) website: Explore their publications, technical papers, and conference proceedings related to well completion and stimulation.
  • OnePetro: A comprehensive online database offering access to numerous technical articles and papers related to the oil and gas industry, including partial completion.
  • Schlumberger Oilfield Glossary: Provides definitions and explanations of key oilfield terms, including partial completion and related techniques.

Search Tips

  • Use specific keywords like "partial completion," "selective perforation," "plugging and perforating," "multi-zone completions," and "well stimulation."
  • Combine keywords with reservoir types like "tight gas sands," "shale formations," and "carbonate reservoirs."
  • Include geographic locations to find regional studies and case studies related to partial completion applications.
  • Use advanced search operators like "site:spe.org" to search within specific websites.

Techniques

Similar Terms
Drilling & Well CompletionProject Planning & SchedulingCost Estimation & Control
Most Viewed
Categories

Comments


No Comments
POST COMMENT
captcha
Back