| dc.description.abstract | The Wisting Field located offshore Norway in the Barents Sea is considered a very challenging field to be developed and produced. Its location in the ice-covering sea in the high North with limited or no sunlight combined with poor infrastructure available to be used due to the high distance from shore and from near fields and an environment that makes any oil spell very challenging to overcome added to a unique well trajectory planned resulted in making the consequences of any small mistake deadly on the environmental, human and economic level. All the previously mentioned reasons forced Equinor and its partners to perform extensive studies to evaluate the effects of the planned trajectory on the casing, as the well is planned to experience 15°/30m dogleg severity. The effects of this dogleg will be evaluated by preparing a setup at the NORCE center that includes a 9 5/8 casing with a production packer. This setup will be tested to the conditions expected at the Wisting Field.
Four strain gauges were installed at four different positions on the casing to measure the strain values resulting from applying forces on the tubing, including the packer and bending (dogleg) on the casing.
This work will focus on using these strain values to find the principal stresses and then the Von Mises stress that will show the stress state on each of the four strain gauges when applying different combinations of loads.
The results showed that strain gauge 1B, located on the lower part of the casing near the top, experienced the largest value of Von Mises stress when all different combinations of loads. This SG also experienced the most significant change in Von Mises stress value when moving from a tension force to a compression force. On the other hand, when testing the effect of the pressure applied, SG 2A showed the largest value of Von Mises stress when moving from zero pressure to 20 MPa.
The work performed will allow knowing the point on the casing that will experience the largest values of stresses when applying forces and the point that will experience the largest change in the stresses when changing the forces applied. | |