Relief Well Profile Analysis and Evaluation of a Passive Seismic Method for Relief Well Placement in the Shallow Wisting Discovery

Manuela Kurz

Research output: ThesisMaster's Thesis

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A blowout is one of the most catastrophic events that can happen in the oil and gas industry, requiring operators to have relief well strategies in place for intersecting the out-of-control well in the worst-case scenario. The Wisting discovery imposes a unique challenge on the relief well trajectory: It is exceptionally shallow, thereby providing too little depth for the industry standard S-shaped design. Therefore, the operator has devised three J-shaped designs for potential relief wells, all of which are difficult to drill because they require either extremely high inclinations or a very high build rate. Further, the intersection process of the blowing well is complicated by the J-shaped design, leading to a longer estimated time for successful intersection and thus to an increased amount of damage in the case of a blowout. To provide a criterion for identifying the best compromise between high build rate and high inclination, the thesis introduces a relationship between the two parameters that allows to derive a most effective build rate and corresponding inclination. The goal is to help the operator decide if one parameter should be reduced on the expense of the other, resulting in an optimized trajectory within the technical limitations of the drilling tools. Further, it provides the operator with comparable, quantitative results to justify the need for the development of higher capability directional drilling tools. To enhance the intersection process with a J-shaped relief well, it is necessary to improve the wellbore positioning accuracy. For this purpose, a seismic event positioning system that has been field tested in Wisting is evaluated for its suitability in reducing the uncertainty in the wellbore position derived from survey measurements. The objective of this evaluation is to assess if further investigation of this seismic method is likely to bring an improvement to the positioning accuracy of directional wells.
Translated title of the contributionAnalyse von Bohrpfaden für Erleichterungsbohrungen und Evaluierung einer passiven seismischen Methode zur Bohrlochpositionsbestimmung in der seichten Lagerstätte Wisting
Original languageEnglish
Awarding Institution
  • Montanuniversität
  • Hollinger, Gerald, Supervisor (external), External person
  • Lettner, Anton, Co-Supervisor (internal)
  • Thonhauser, Gerhard, Supervisor (internal)
Award date14 Dec 2018
Publication statusPublished - 2018

Bibliographical note

embargoed until 04-11-2023


  • relief well
  • trajectory
  • trajectory design
  • J-shape
  • S-shape
  • Wisting
  • wellbore positioning
  • seismic event positioning
  • shallow

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