The work reported here investigated construction designs for deep wells in the Vienna basin. The work is based on two wells; Straßhof T4 and T5. In this report, both wells are analysed and different factors defined: well trajectory, temperature, casing design, pressure, geology, work time and costs. The data from the actual wells are compared with their planned data. Finally, a summary of drilling problems incurred is given. Based on data from these wells, the casing loads calculation standards are compared with the recommendations of the Wirtschaftsverband Erdöl- und Erdgasgewinnung (WEG). The calculations of the tension, collapse and burst loads are analysed by well and section. Findings from a third-party study are included. Casing hangers and their resisting loads are discussed based on this study, and the casing loads calculation spreadsheet reworked to include findings like temperature, safety factor, compression and biaxial loads. Conventional design alternatives created are given: four regular diameter alternatives and two tighter designs. Novel technologies found are described: expandable casing, liner hangers and contingency, monodiameter liners and wells, casing while drilling, fibre glass and self-expandable casing. Some aspects of the completion are given. A risk analysis and evaluation of costs is included. Finally, a recommendation for a specific casing design is given.
|Translated title of the contribution||Bohrlochverrohrungsschemata für Tiefbohrungen im Wiener Becken|
|Award date||14 Dec 2007|
|Publication status||Published - 2007|