TY - THES

T1 - Evaluation of Dynamic Loads Running Tubulars in Wells

AU - Mühlböck, Michael

N1 - embargoed until null

PY - 2009

Y1 - 2009

N2 - The objective of this master thesis was, to find out, if dynamic shock loads could have been a reason that a 16 casing got weakened and as later consequence failed in a depth of 2,440 m. There had already been a thesis on this problem which was written by Jedlitschka which had the result that a water hammer could not have been the reason for this failure. Some simple calculations were done with an Excel-Spreadsheet which was used to find out the intensity of these dynamic loads. To be sure that the results are correct a simulation software called Abaqus, which is based on the finite element method, was applied. The same situation was calculated with this programme and the values were compared with the first assumptions. To approve these former computations a field test was set up which should measure the speed of the top drive, the loads that appear when setting the string into the slips and the closure time of the slips. Unfortunately this could not be performed but can be used as support for further thesis or dissertations in this region. Further was then decided to extend the research also for drill pipes and calculations should be made for strings in extreme conditions. This was done by simulating the dynamic loads in Abaqus for several velocities. Different sizes, grades and length of drill pipes and casings were used. With these results a graph was created in which we can evaluate the maximum allowable travelling velocity of a string in dependence of the dynamic loads.

AB - The objective of this master thesis was, to find out, if dynamic shock loads could have been a reason that a 16 casing got weakened and as later consequence failed in a depth of 2,440 m. There had already been a thesis on this problem which was written by Jedlitschka which had the result that a water hammer could not have been the reason for this failure. Some simple calculations were done with an Excel-Spreadsheet which was used to find out the intensity of these dynamic loads. To be sure that the results are correct a simulation software called Abaqus, which is based on the finite element method, was applied. The same situation was calculated with this programme and the values were compared with the first assumptions. To approve these former computations a field test was set up which should measure the speed of the top drive, the loads that appear when setting the string into the slips and the closure time of the slips. Unfortunately this could not be performed but can be used as support for further thesis or dissertations in this region. Further was then decided to extend the research also for drill pipes and calculations should be made for strings in extreme conditions. This was done by simulating the dynamic loads in Abaqus for several velocities. Different sizes, grades and length of drill pipes and casings were used. With these results a graph was created in which we can evaluate the maximum allowable travelling velocity of a string in dependence of the dynamic loads.

KW - Bohrgestänge Casing dynamische Lasten Abaqus Einbaugeschwindigkeit

KW - drill pipe casing dynamic load Abaqus travel velocity

M3 - Master's Thesis

ER -