Dr. Jerome J. Schubert, Texas A&M University Dr. Jonggeun Choe, Seoul National University, Korea Mr. Bjorn Gjorv, Texas A&M University Mr. Max Long, Texas A&M University
Final Project Report Prepared for the Minerals Management Service Under the MMS/OTRC Cooperative Research Agreement 1435-01-99-CA-31003 Task Order 85222 Project Number 440
OTRC Library Number: 12/04-A146
“The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the opinions or policies of the U.S. Government. Mention of trade names or commercial products does not constitute their endorsement by the U. S. Government”.
For more information contact:
Offshore Technology Research Center
Texas A&M University 1200 Mariner Drive College Station, Texas 77845-3400 (979) 845-6000 or Offshore Technology Research Center
The University of Texas at Austin 1 University Station C3700 Austin, Texas 78712-0318 (512) 471-6989 A National Science Foundation Graduated Engineering Research Center
DEVELOPMENT AND ASSESSMENT OF WELL CONTROL PROCEDURES FOR EXTENDED REACH AND MULTILATERAL WELLS UTILIZING COMPUTER SIMULATION EXECUTIVE SUMMARY
Project Description This project included four tasks. Task 1 - Perform a literature search of the state of the art in well control for vertical, directional, horizontal, extended reach, and multi-lateral wells. Task 2 - Modify an existing Windows-based well control simulator that has been developed by Dr. Jonggeun Choe for use in more conventional wellbores to model extended reach and multilateral wells. Task 3 - Use the simulator to evaluate, compare, and contrast the current well control procedures utilized for vertical, directional, horizontal, extended reach, and multi-lateral wells. Task 4 - Based on the results of the simulation study, recommendations will be made to improve well control for any situations that warrant improvement, especially for the extended reach and multilateral wells. Progress Task 1 – The literature review of the state of the art in well control for vertical, directional, horizontal, extended reach, and multi-lateral wells was completed. Task 2 – The Windows-based simulator was modified as follows in accordance with the specifications in the project proposal: • Modify and update an existing conventional simulator using Visual Basic v.6.0 • Modify the simulator to model extended reach wells • Take into account gas compressibility factor on casing pressure and drill pipe pressure • Take into account compressibility of mud and formation on well stabilization • Modify the simulator to handle multilateral wells • Use the simulator to evaluate and compare current and new procedures, if any, from this study • Develop a Windows-based well control program with the following capabilities: − Ability to modify, save, and retrieve input data files
− Ability to save results as an output files − Graphical presentation of results For a full description of the simulator see Part I Task 3 – We have completed our comparison of well control for vertical, horizontal, extended reach, and multilateral wellbores. A full description can be found in Part II and Part III. Surface Gas Flow Rates - In Part II, Bjorn Gjerv used the Multilateral/Extend Reach Well Control Simulator to study the effect of different water depth, well depth (vertical and measured), influx volume, circulation rates, and horizontal displacement on the anticipated wellbore pressures during kick circulation for non vertical wells, and compared their differences. Possible instantaneous surface gas flow rates and pressures were reported for the various well scenarios. Results indicated that instantaneous gas flow rates in excess of 7MMSCF/Day could be expected. These results can be used to compare the design capabilities of mud/gas...