DOCSLIB.ORG

Coal Mine Methane Recovery: a Primer

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Coal Mine Methane Recovery: a Primer Coal Mine Methane Recovery: A Primer U.S. Environmental Protection Agency July 2019 EPA-430-R-09-013 ACKNOWLEDGEMENTS This report was originally prepared under Task Orders No. 13 and 18 of U.S. Environmental Protection Agency (USEPA) Contract EP-W-05-067 by Advanced Resources, Arlington, USA and updated under Contract EP-BPA-18-0010. This report is a technical document meant for information dissemination and is a compilation and update of five reports previously written for the USEPA. DISCLAIMER This report was prepared for the U.S. Environmental Protection Agency (USEPA). USEPA does not: (a) make any warranty or representation, expressed or implied, with respect to the accuracy, completeness, or usefulness of the information contained in this report, or that the use of any apparatus, method, or process disclosed in this report may not infringe upon privately owned rights; (b) assume any liability with respect to the use of, or damages resulting from the use of, any information, apparatus, method, or process disclosed in this report; or (c) imply endorsement of any technology supplier, product, or process mentioned in this report. ABSTRACT This Coal Mine Methane (CMM) Recovery Primer is an update of the 2009 CMM Primer, which reviewed the major methods of CMM recovery from gassy mines. [USEPA 1999b, 2000, 2001a,b,c] The intended audiences for this Primer are potential investors in CMM projects and project developers seeking an overview of the basic technical details of CMM drainage methods and projects. The report reviews the main pre-mining and post-mining CMM drainage methods with associated costs, water disposal options and in-mine and surface gas collection systems. Updates from previous EPA reports include advances in mining and CMM drainage techniques, directional drilling technologies (from the surface and in-mine), costs of the various drainage methods, and references to the latest research papers and presentations covering CMM drainage issues. i CONTENTS Acknowledgements, Disclaimer, Abstract ......................................................................... i Glossary of Terms .............................................................................................................. v Abbreviations .................................................................................................................... vii 1. Introduction ................................................................................................................... 1 1.1 Coal mining practices ................................................................................................. 3 1.2 Methane generation, retention and migration in coal................................................... 4 1.3 Emissions of methane in coal mines ........................................................................... 5 1.4 Methane control by ventilation .................................................................................... 6 1.5 Overview of methane drainage practices .................................................................... 7 2. CMM drainage techniques to reduce in-situ gas content ........................................... 8 2.1 Vertical wells .............................................................................................................. 8 2.1.1 Planning and design .......................................................................................... 10 2.1.2 Well bore completion ......................................................................................... 11 2.1.3 Stimulation technologies .................................................................................... 13 2.1.4 Gas content reduction and production ............................................................... 16 2.1.5 Costs ................................................................................................................. 17 2.2 Horizontal in-seam boreholes ................................................................................... 17 2.2.1 Short holes ........................................................................................................ 18 2.2.2 Long holes ......................................................................................................... 19 2.2.3 Superjacent boreholes ....................................................................................... 23 2.3 Surface-drilled directional boreholes ......................................................................... 23 2.3.1 Directional borehole drilling techniques .............................................................. 24 2.3.2 Gas content reduction and production ............................................................... 27 2.3.3 Costs ................................................................................................................. 28 2.4 Water disposal .......................................................................................................... 28 2.4.1 Water disposal options ...................................................................................... 29 3. CMM drainage techniques to recover gob gas ......................................................... 32 3.1 Vertical gob wells ...................................................................................................... 34 3.1.1 Planning and design .......................................................................................... 34 3.1.2 Gob well completion .......................................................................................... 35 3.1.3 Gob gas production and quality ......................................................................... 36 ii CONTENTS 3.2 Cross-measure techniques ....................................................................................... 38 3.2.1 Planning and design .......................................................................................... 39 3.2.2 Recovered gas quality and production ............................................................... 42 3.3 Superjacent techniques ............................................................................................ 43 3.3.1 Overlying or underlying galleries ........................................................................ 43 3.3.2 Directionally drilled gob boreholes ..................................................................... 45 4. Gas gathering and collection ..................................................................................... 48 4.1 Underground gas collection systems ........................................................................ 48 4.1.1 Pipelines ............................................................................................................ 48 4.1.2 Safety devices ................................................................................................... 49 4.1.3 Water separation ............................................................................................... 50 4.1.4 Monitoring and control ....................................................................................... 50 4.1.5 Underground gas movers .................................................................................. 51 4.2 Surface gas collection systems ................................................................................. 51 4.2.1 Pipelines ............................................................................................................ 52 4.2.2 Compression ..................................................................................................... 52 4.2.3 Gas processing .................................................................................................. 52 5. Summary ...................................................................................................................... 54 5.1 Benefits of CMM drainage for coal mines ................................................................. 54 5.2 Environmental benefits of CMM drainage ................................................................. 56 6. References ................................................................................................................... 58 iii EXHIBITS Exhibit 1: Global methane emissions from coal mining (2010) ........................................... 2 Exhibit 2: Retreat longwall mining ...................................................................................... 4 Exhibit 3: Methane migration in coal ................................................................................... 5 Exhibit 4: Typical ventilation configuration at a U.S. longwall mine ..................................... 6 Exhibit 5: Typical vertical well setup ................................................................................... 9 Exhibit 6: Major U.S. CBM basins .................................................................................... 10 Exhibit 7: Under-reamed CBM completion ....................................................................... 13 Exhibit 8: Hydraulic fracturing schematic .......................................................................... 14 Exhibit 9: Schematic plan view of short horizontal boreholes in longwall panels ............... 19 Exhibit 10: Longhole drilling from within a mine entry ......................................................... 20 Exhibit 11: Plan view of horizontal methane drainage borehole patterns modeled for degasification of a longwall panel (not to scale) ...............................................
Load more

Recommended publications
  • Modern Shale Gas Development in the United States: a Primer
    U.S. Department of Energy • Office of Fossil Energy National Energy Technology Laboratory April 2009 DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe upon privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. Modern Shale Gas Development in the United States: A Primer Work Performed Under DE-FG26-04NT15455 Prepared for U.S. Department of Energy Office of Fossil Energy and National Energy Technology Laboratory Prepared by Ground Water Protection Council Oklahoma City, OK 73142 405-516-4972 www.gwpc.org and ALL Consulting Tulsa, OK 74119 918-382-7581 www.all-llc.com April 2009 MODERN SHALE GAS DEVELOPMENT IN THE UNITED STATES: A PRIMER ACKNOWLEDGMENTS This material is based upon work supported by the U.S. Department of Energy, Office of Fossil Energy, National Energy Technology Laboratory (NETL) under Award Number DE‐FG26‐ 04NT15455. Mr. Robert Vagnetti and Ms. Sandra McSurdy, NETL Project Managers, provided oversight and technical guidance.
    [Show full text]
  • The Hydrology of Coalbed Methane Reservoirs and the Interplay of Gas, Water, and Coal in CBM Production
    University of Colorado Law School Colorado Law Scholarly Commons Coalbed Methane Development in the Intermountain West (April 4-5) 2002 4-4-2002 The Hydrology of Coalbed Methane Reservoirs and the Interplay of Gas, Water, and Coal in CBM Production Leslie Nogaret Follow this and additional works at: https://scholar.law.colorado.edu/coalbed-methane-development- intermountain-west Part of the Geotechnical Engineering Commons, Hydraulic Engineering Commons, Hydrology Commons, Natural Resources Management and Policy Commons, Oil, Gas, and Energy Commons, Science and Technology Law Commons, and the Water Resource Management Commons Citation Information Nogaret, Leslie, "The Hydrology of Coalbed Methane Reservoirs and the Interplay of Gas, Water, and Coal in CBM Production" (2002). Coalbed Methane Development in the Intermountain West (April 4-5). https://scholar.law.colorado.edu/coalbed-methane-development-intermountain-west/9 Reproduced with permission of the Getches-Wilkinson Center for Natural Resources, Energy, and the Environment (formerly the Natural Resources Law Center) at the University of Colorado Law School. Leslie Nogaret, The Hydrology of Coalbed Methane Reservoirs and the Interplay of Gas, Water, and Coal in CBM Production, in COALBED METHANE DEVELOPMENT IN THE INTERMOUNTAIN WEST (Natural Res. Law Ctr., Univ. of Colo. Sch. of Law 2002). Reproduced with permission of the Getches-Wilkinson Center for Natural Resources, Energy, and the Environment (formerly the Natural Resources Law Center) at the University of Colorado Law School. References Lyons, W.S., 2002, Seismic Assists Geologic Interpretation and Development Program in the Ferron Bowles, J., 2001, Phillips’ CBM Outlook, A.G. Edwards, Coalbed Methane Play, presentation to the Rocky March 14, 2001, Coal Bed Methane Energy Mountain Section of SEPM, February 26, 2002.
    [Show full text]
  • The Strip Mining Handbook
    1 FOREWORD 2 by 3 U.S. Rep. Morris K. Udall, Chairman 4 House Interior and Insular Affairs Committee 5 January, 1990 6 Congressman Morris (“Mo”) Udall, tireless champion of the federal strip mining laws, passed away on December 12, 1998. This foreword, which first appeared in the 1980 edition of this book, is included in its entirety as a tribute to Mo and to his extraordinary efforts to protect the public and the environment from the ravages of strip mining. 7 8 9 In the 1960's and early 1970's coal strip mining quickly overwhelmed underground mining as the 10 dominant mining method. But the new mining methods brought ravaged hillsides and polluted streams 11 to the once-beautiful landscape. State governments proved ill-equipped to prevent the severe 12 environmental degradation that this new mining method left in its wake. From our rivers, forests and 13 Appalachian Mountains in the East, to our prime farmlands of the Midwest, to our prairies and deserts of the 14 great West, stories abound during this time of reckless coal operators devastating landscapes, polluting 15 the water, destroying family homes, churches and cemeteries, and threatening fragile ecosystems. Perhaps 16 the most tragic case of abuse came on February 26th, 1972, at Buffalo Creek in Logan County, West Virginia, 17 when a crudely constructed coal waste dam collapsed causing a flood that killed 125 people, left scores of 18 others homeless, and caused millions of dollars in property damage. Something had to be done. 19 I was proud to stand in the White House Rose Garden on August 3rd, 1977, to witness the President sign 20 into law a bill that I sponsored — the federal Surface Mining Control and Reclamation Act (SMCRA).
    [Show full text]
  • Assessment of Contaminants Associated with Coal Bed Methane
    Contaminant Report Number: R6/721C/05 U.S. FISH & WILDLIFE SERVICE REGION 6 CONTAMINANTS PROGRAM Assessment of Contaminants Associated with Coal Bed Methane-Produced Water and Its Suitability for Wetland Creation or Enhancement Projects USFWS - Region 6 - EC Report - R6/721C/05 ABSTRACT Extraction of methane gas from coal seams has become a significant energy source in the Powder River Basin of northeastern Wyoming. In Wyoming, coalbed methane (CBM) gas is extracted by drilling wells into coal seams and removing water to release the gas. Each CBM well produces an average of 10 gallons per minute (gpm) of water and a maximum of 100 gpm. Disposal of CBM produced water is accomplished by direct discharge to surface drainages, and also by a variety of other treatment and disposal methods. Untreated CBM produced water discharged to surface drainages is the primary method of disposal provided that the CBM produced water meets Wyoming water quality standards. Water failing to meet water quality standards cannot legally be discharged into surface drainages and is alternately discharged into closed containment ponds for soil-ground water infiltration and evaporation. In 2000 and 2001, we collected and analyzed water from CBM discharges and receiving waters and sediment and biota from CBM produced water impoundments. In 2002, we collected and analyzed water from CBM closed containment impoundments. All the samples were analyzed for trace elements. The biota included pondweed (Potamogeton vaginatus), aquatic invertebrates, fish, and tiger salamanders (Ambystoma tigrinum). One CBM produced water discharge exceeded the chronic criterion for iron and several CBM produced water discharges exceeded the acute criterion for copper.
    [Show full text]
  • Fracking Fights Are Increasingly Becoming Local Law360, New York (July 02, 2014, 11:29 AM ET)
    Portfolio Media. Inc. | 860 Broadway, 6th Floor | New York, NY 10003 | www.law360.com Phone: +1 646 783 7100 | Fax: +1 646 783 7161 | [email protected] Fracking Fights Are Increasingly Becoming Local Law360, New York (July 02, 2014, 11:29 AM ET) -- On May 7, 2014, a petition to ban hydraulic fracturing was submitted to the city council in Denton, Texas. The petition aims to make fracking illegal within the boundary limits of Denton, which is believed to sit upon one of the largest natural gas reserves in the U.S. Currently, all oil and gas drilling is prohibited in the city, because the council voted in favor of a moratorium that will last until Sept. 9 of this year. If the city council ultimately adopts the permanent ban, Denton will become the first city in Texas to prohibit the practice. However, if the council votes against the ban, the initiative will likely find its way onto the ballot in November, allowing the public to decide the issue.[1] Fracking is the high-pressure injection of a mix of fluids and other substances into an oil or gas reservoir. The injection into the bottom of a well fractures the reservoir rock, unlocking hydrocarbons trapped in the reservoir formations. Other substances in the fracking fluid called “proppants” hold the cracks in the reservoir rock open Jeffrey D. Dintzer and allow the oil or natural gas to flow up and out of the reservoir through the well. Conventional fracking is a common practice that has been employed in oil and gas operations for over 60 years.
    [Show full text]
  • Articles on Mining History from Mining and History
    North of England Institute of Mining and Mechanical Engineers Nicholas Wood Memorial Library Articles on mining history from mining and history journals: a list May 2017 These are mainly from the Transactions of the professional mining institutions and from economic and other history journals and are grouped in broad topics as well as in a complete list. Some references may appear in more than one grouping. They all relate to the UK. It is a work in progress and further articles will be added from time to time. Publications from mining history societies are mostly not included, but an online index at http://www.sat.dundee.ac.uk/bin/pdmhsearch covers articles from British Speleological Association 1947-73 Northern Cave and Mine Research Society 1961-74 Northern Mine Research Society 1975- (British Mining) Peak District Mines Historical Society 1959- The complete list of articles is followed by the subject groupings: General mining history Labour: miners; productivity Legislation Metalliferous and other non-coal mining Mining technologies Professional institutions; education Regional studies Safety and inspection Safety lamps Items marked X are not in the Institute Library. Page 1 Author Title Journal vol date pages Adam, T.W. The history of the Midland Institute of Mining Engineers Transactions – Institution of 106 1946-7 166-175 Mining Engineers Adam, T.W. & A historical review of the Midland Institute of Mining Transactions – Institution of 117 1957-8 606-620 Statham, I.C.F. Engineers Mining Engineers Adams, M Humphry Davy and the murder lamp History today 55 2005 207-208 X Almond, J.K. British technical education for mining: an historical survey to Transactions - Institution of 84 1975 A60-A70 1920.
    [Show full text]
  • Manual Borehole Drilling As a Cost-Effective Solution for Drinking
    water Review Manual Borehole Drilling as a Cost-Effective Solution for Drinking Water Access in Low-Income Contexts Pedro Martínez-Santos 1,* , Miguel Martín-Loeches 2, Silvia Díaz-Alcaide 1 and Kerstin Danert 3 1 Departamento de Geodinámica, Estratigrafía y Paleontología, Universidad Complutense de Madrid, Ciudad Universitaria, 28040 Madrid, Spain; [email protected] 2 Departamento de Geología, Geografía y Medio Ambiente, Facultad de Ciencias Ambientales, Universidad de Alcalá, Campus Universitario, Alcalá de Henares, 28801 Madrid, Spain; [email protected] 3 Ask for Water GmbH, Zürcherstr 204F, 9014 St Gallen, Switzerland; [email protected] * Correspondence: [email protected]; Tel.: +34-659-969-338 Received: 7 June 2020; Accepted: 7 July 2020; Published: 13 July 2020 Abstract: Water access remains a challenge in rural areas of low-income countries. Manual drilling technologies have the potential to enhance water access by providing a low cost drinking water alternative for communities in low and middle income countries. This paper provides an overview of the main successes and challenges experienced by manual boreholes in the last two decades. A review of the existing methods is provided, discussing their advantages and disadvantages and comparing their potential against alternatives such as excavated wells and mechanized boreholes. Manual boreholes are found to be a competitive solution in relatively soft rocks, such as unconsolidated sediments and weathered materials, as well as and in hydrogeological settings characterized by moderately shallow water tables. Ensuring professional workmanship, the development of regulatory frameworks, protection against groundwater pollution and standards for quality assurance rank among the main challenges for the future.
    [Show full text]
  • Coal Introduction Geology of Coal Formation of Coal
    COAL INTRODUCTION STATE OF OHIO Ted Strickland, Governor Coal is one of Ohio’s most valuable mineral resources DEPARTMENT OF NATURAL RESOURCES and the nation’s most abundant fossil fuel. More than 3.7 bil- Sean D. Logan, Director lion tons of Ohio coal has been mined since 1800, and recent DIVISION OF GEOLOGICAL SURVEY fi gures indicate that Ohio is the 3rd largest coal-consuming Larry Wickstrom, Chief state in the nation, consuming about 62 million tons per year. Ohio ranks 13th in the nation in coal production, and 7th in terms of demonstrated coal reserves with approximately 23.3 billion short tons, or 4.7% of the nation’s total coal reserves. (“Demonstrated Coal Reserve” is a term used to identify the part of the total resource that is potentially mineable when considering economic, legal, and engineering constraints). At present production levels, Ohio has more than 500 years worth of potentially mineable coal remaining. GEOLOGY OF COAL Th e coal-bearing rocks of Ohio were deposited during the Pennsylvanian and Permian Periods, approximately 320 to 245 million years ago. During Pennsylvanian time, or the great Coal Age, a shallow sea covered central Ohio. A series of river deltas extended into this sea carrying sediments that eroded from the ancestral Appalachian Mountains and fl owed northwest into the deltas. Extensive freshwater and brackish-water peat-forming COAL ecosystems formed in these low-lying coastal and near-coastal deltas, which were similar to those of the current Mississippi and Amazon Rivers. Th ese peat swamps remained undisturbed for thousands of years.
    [Show full text]
  • The Coal Mining Heritage of Lafayette
    The Coal Mining Heritage of Lafayette From the late I 880s until the I 930s, Lafayette was a major coal town. Read the history of the coal mining era, examine the location of coal mines within the Lafayette area, and enjoy historic photos of the Waneka Lake Power Plant and the Simpson Mine with the attached Coal Mines of the Lafaveti’e Area brochure. This brochure was created by the Lafayette Historic Preservation board, and it highlights the fascinating Coal Mining Heritage of Lafayette. oft/ic — • Coal Mines Lafayette Area page 1 • Coal Mines of the Lafayette Area - page 2 • Coal Mines f the Lfa)’ette Area — map ____________________________ Historic Preservation Board, City of Lafayette, Colorado The social legacy. The social legacy of mining is equally important to contemporary Lafayette The mines required far more labor than was available locally and quickly attracted experienced miners and laborers from Europe and other parts of the U.S. The result was a community comprised of many ethnic groups, including Welsh, English. Scottish, Irish, central European, Hispanic, Italian, and Swedish workers and their families. Local farmers and ranchers also shared in the coal boom and worked as miners in the winter when coal production was high and agricultural work slow. A sense of this ethnic diversity can be gained by walking through the Lafayette cemetery at Baseline and 111th Street. The variety of family names gives a sense of the many nationalities that have contributed to Lafayette’s history. Although the mining life was hard, families were fun-loving and many social activities centered around schools and churches.
    [Show full text]
  • 2008 Abstract Booklet
    TWENTY - FIFTH ANNUAL INTERNATIONAL PITTSBURGH COAL CONFERENCE COAL - ENERGY, ENVIRONMENT AND SUSTAINABLE DEVELOPMENT ABSTRACTS BOOKLET September 29 - October 2, 2008 The Westin Convention Center Pittsburgh, PA USA The Westin Hotel and Convention Center Hosted By: University of Pittsburgh Swanson School of Engineering A NOTE TO THE READER This Abstracts Booklet is prepared solely as a convenient reference for the Conference participants. Abstracts are arranged in a numerical order of the oral and poster sessions as published in the Final Conference Program. In order to facilitate the task for the reader to locate a specific abstract in a given session, each paper is given two numbers: the first designates the session number and the second represents the paper number in that session. For example, Paper No. 25-1 is the first paper to be presented in the Oral Session #25. Similarly, Paper No. P3-1 is the first paper to appear in the Poster Session #3. It should be cautioned that this Abstracts Booklet is prepared based on the original abstract that was submitted, unless the author noted an abstract change. The contents of the Booklet do not reflect late changes made by the authors for their presentations at the Conference. The reader should consult the Final Conference Program for any such changes. Furthermore, updated and detailed full manuscripts are published in the CD-ROM Conference Proceedings will be sent to all registered participants following the Conference. On behalf of the Twenty-Fifth Annual International Pittsburgh Coal Conference, we wish to express our sincere appreciation to Ms. Heidi M. Aufdenkamp, Mr.
    [Show full text]
  • T U R G a Y E R T E K I N, B.Sc, M.Sc., Ph.D
    T U R G A Y E R T E K I N, B.Sc, M.Sc., Ph.D. ● P E N N S T A T E U N I V E R S I T Y ● U N I V E R S I T Y P A R K , P A 1 6 8 7 0 ● ● (8 14 ) 8 6 5 - 6 0 8 2 ● Professor Emeritus Petroleum and Natural Gas Engineering E DUC A T I ON Middle East Technical University, Ankara, Turkey, B.Sc., 1969, Petroleum Engineering Middle East Technical University, Ankara, Turkey, M.Sc., 1971, Petroleum Engineering Pennsylvania State University, University Park, USA, Ph.D., 1978, Petroleum and Natural Gas Engineering A C A D E M IC A N D A D M INIST R A T IVE P O S ITION S July 2017 to present Professor Emeritus of Petroleum and Natural Gas Engineering The Pennsylvania State University July 2013 to July 2017 Head, John and Willie Leone Family Department of Energy and Mineral Engineering, the George E. Trimble Chair in Earth and Mineral Sciences, the Pennsylvania State University May 2013 to May 2014 Co-Director, Institute of Natural Gas Research (INGaR), Pennsylvania State University July 2001 to Present Professor of Petroleum and Natural Gas Engineering and George E. Trimble Chair in Earth and Mineral Sciences, Pennsylvania State University July 1998 to June 2001 Associate Head, Department of Energy and Geo-Environmental Engineering July 1987 to Present Professor of Petroleum and Natural Gas Engineering, Pennsylvania State University July 1984 to January 2015 Chairman of Petroleum and Natural Gas Engineering, Pennsylvania State University July 1983 to July 1984 Associate Professor of Petroleum and Natural Gas Engineering, Pennsylvania State University
    [Show full text]
  • (12) United States Patent (10) Patent No.: US 8,505,620 B2 Zupanick (45) Date of Patent: *Aug
    US00850562OB2 (12) United States Patent (10) Patent No.: US 8,505,620 B2 Zupanick (45) Date of Patent: *Aug. 13, 2013 (54) METHOD AND SYSTEM FOR ACCESSING (58) Field of Classification Search SUBTERRANEAN DEPOSTS FROM THE USPC .............................................. 166/50, 52, 245 SURFACE AND TOOLS THEREFOR See application file for complete search history. (75) Inventor: Joseph A. Zupanick, Beckley, WV (US) (56) References Cited (73) Assignee: Vitruvian Exploration, LLC, Houston, U.S. PATENT DOCUMENTS TX (US) 54,144 A 4, 1866 Hamar 274,740 A 3/1883 Douglass (*) Notice: Subject to any disclaimer, the term of this (Continued) patent is extended or adjusted under 35 U.S.C. 154(b) by 0 days. FOREIGN PATENT DOCUMENTS AU 85,49964 A 11, 1986 This patent is Subject to a terminal dis CA 2210866 1, 1998 claimer. (Continued) (21) Appl. No.: 11/982,249 OTHER PUBLICATIONS (22) Filed: Oct. 31, 2007 McCray, Arthur, et al., “Oil Well Drilling Technology.” University of Oklahoma Press, 1959, Title Page, Copyright Page and pp. 315-319 (65) Prior Publication Data (7 pages). US 2008/OO60806A1 Mar. 13, 2008 (Continued) Primary Examiner — John Kreck Related U.S. Application Data (74) Attorney, Agent, or Firm — Fish & Richardson P.C. (60) Continuation of application No. 10/630,345, filed on Jul. 29, 2003, which is a continuation-in-part of (57) ABSTRACT According to one embodiment, a system for accessing a Sub (Continued) terranean Zone from the surface includes a well bore extend ing from the Surface to the Subterranean Zone, and a well bore (51) Int. C. pattern connected to the junction and operable to drain fluid E2IB 43/00 (2006.01) from a region of the Subterranean Zone to the junction.
    [Show full text]