Demystifying DLL and Other Oil & Gas Jargon: DLS, Dog Leg Severity, and More
The oil and gas industry boasts a rich lexicon of specialized terms, often bewildering for those outside the field. This article aims to shed light on some common acronyms and concepts, offering a concise glossary to navigate this unique language.
DLL: Dual Laterolog
DLL stands for Dual Laterolog, a specific type of well logging technique used to measure the resistivity of formations surrounding a borehole. This method employs two sets of electrodes: one to create a current field and another to measure the potential difference. The Dual Laterolog helps determine the resistivity of the formation, crucial for identifying potential hydrocarbon reservoirs.
DLS: Dog Leg Severity
Dog Leg Severity (DLS) is a measure of the sharpness of a wellbore's curvature. It quantifies the change in direction of the wellbore over a specific distance, expressed in degrees per 100 feet. High DLS values indicate a sharp bend, which can pose challenges for drilling and wellbore stability.
Dog Leg Severity is an important consideration in well planning, as it can affect:
- Drilling efficiency: Sharp turns can slow down drilling progress and increase wear on drilling tools.
- Wellbore stability: High DLS can lead to borehole instability and collapse.
- Completion operations: Sharp bends can complicate the placement of casing and production equipment.
Other Relevant Terms:
- Formation: A geological layer of rock with distinct characteristics.
- Resistivity: A material's ability to oppose the flow of electrical current.
- Wellbore: The hole created by drilling in the earth.
- Logging: The process of recording information about the geological formations encountered during drilling.
Understanding these terms and concepts is essential for navigating the complexities of the oil and gas industry. By familiarizing yourself with this specialized vocabulary, you can better comprehend the technical aspects of exploration, drilling, and production.
Test Your Knowledge
Quiz: Demystifying DLL and Other Oil & Gas Jargon
Instructions: Choose the best answer for each question.
1. What does DLL stand for? a) Deep Laterolog Logging b) Dual Laterolog c) Directional Lateral Logging d) Dynamic Lateral Logging
Answer
b) Dual Laterolog
2. What does DLS measure? a) The diameter of the wellbore b) The depth of the well c) The sharpness of a wellbore's curvature d) The rate of drilling
Answer
c) The sharpness of a wellbore's curvature
3. What is the unit of measurement for Dog Leg Severity (DLS)? a) Feet per 100 degrees b) Degrees per 100 feet c) Meters per 100 degrees d) Degrees per 100 meters
Answer
b) Degrees per 100 feet
4. Why is high DLS considered a challenge in drilling operations? a) It can lead to increased drilling time and wear on equipment. b) It can cause instability and collapse of the wellbore. c) It can complicate the placement of casing and production equipment. d) All of the above
Answer
d) All of the above
5. Which of the following is NOT a relevant term in the context of DLL and DLS? a) Formation b) Resistivity c) Wellbore d) Seismic Reflection
Answer
d) Seismic Reflection
Exercise: Calculating DLS
Scenario: A wellbore changes direction by 15 degrees over a distance of 50 feet. Calculate the Dog Leg Severity (DLS) of this section.
Instructions: 1. Use the formula: DLS = (Change in Direction / Distance) * 100 2. Express the DLS value in degrees per 100 feet.
Exercice Correction
DLS = (15 degrees / 50 feet) * 100 DLS = 30 degrees per 100 feet
Books
- Petroleum Engineering: Drilling and Well Completions by Adam J. E. M. Edwards & John S. Bell: This textbook covers drilling and well completion techniques, including wellbore stability and logging. It would be a valuable resource for understanding DLS and DLL.
- Elements of Petroleum Geology by K.A. K. Rahman: This book provides a comprehensive overview of petroleum geology, including formation evaluation and reservoir characterization. It can offer context for understanding resistivity measurements and their significance in reservoir exploration.
- The Oil and Gas Industry: A Comprehensive Guide by T.H. Taffs & A. C. Taffs: This book provides a broad introduction to the oil and gas industry, including terminology and concepts. It is a good starting point for those new to the field.
Articles
- "Dual Laterolog Logging: A Powerful Tool for Reservoir Characterization" by [author name] in [journal name]: Search for articles specifically about Dual Laterolog logging in reputable journals like SPE Journal or Petrophysics.
- "Dog Leg Severity: A Critical Factor in Well Planning and Execution" by [author name] in [journal name]: Look for articles on Dog Leg Severity and its impact on wellbore stability and drilling efficiency. You can find these in journals like Journal of Petroleum Technology or Drilling and Completion.
Online Resources
- SPE (Society of Petroleum Engineers): SPE website provides a wealth of resources for oil and gas professionals, including technical papers, conferences, and online courses. Search their website for specific topics like DLL, DLS, and wellbore stability.
- OnePetro: This online platform offers a collection of technical papers and publications from various oil and gas organizations, including SPE, AAPG (American Association of Petroleum Geologists), and others. It's a valuable resource for finding research papers related to well logging and drilling.
- Wikipedia: While not a primary source, Wikipedia can provide a basic overview of terms like DLL and DLS, along with links to more detailed resources.
- Schlumberger: As a leading oilfield services company, Schlumberger provides technical information and insights on various aspects of oil and gas exploration and production, including logging technologies like Dual Laterolog.
Search Tips
- Use specific keywords: For example, "Dual Laterolog logging techniques," "Dog Leg Severity calculation," "wellbore stability DLS," etc.
- Combine keywords: Try searching for "DLL AND wellbore stability" or "DLS AND drilling efficiency" to narrow your search.
- Use quotation marks: Put phrases in quotation marks to find exact matches. For instance, "Dual Laterolog" will only return results with that exact term.
- Use the "site:" operator: Limit your search to specific websites. For example, "site:spe.org dual laterolog" will only search the SPE website.
- Explore different formats: Look for websites, articles, videos, and other resources related to your search term.
