dc.contributor.author | Jokela, Tommy | |
dc.date.accessioned | 2010-10-21T15:15:18Z | |
dc.date.available | 2010-10-21T15:15:18Z | |
dc.date.issued | 2010 | |
dc.identifier.uri | http://hdl.handle.net/11250/183289 | |
dc.description | Master's thesis in Petroleum engineering | en_US |
dc.description.abstract | Ula is an oil field operated by BP in the southern part of the Norwegian North Sea. As the
field matures depleted intervals are drilled to access remaining reserves. Drilling in highly
mature fields is challenging, both with respect to loss of circulation and differential sticking.
On the Ula field there is a pressure barrier/baffle isolating parts of the Ula reservoir units.
This pressure barrier creates a pressure differential between the units. The units above the
barrier (1A1-1A2) have been produced since 1998 without any pressure support, resulting in
a pressure decrease in this zone. The units beneath the barrier (Units 2-3) have been
produced since 1987 and have been supported by both water- and WAG-injection, giving a
much higher formation pressure in these units compared to the units above the barrier. The
pressure differential between Units 1 and 2 have produced challenges drilling this interval in
terms of losses during drilling and cementing operations.
This thesis describes the challenges in drilling depleted formations with respect to lost
returns and differential sticking. The Ula field in the North Sea will be the primary focus
throughout the thesis. The study involves reviewing BP’s drilling practices on the Ula field
and proposing potential recommendations and improvements. Maximum overbalance on the
Ula field and different options for drilling depleted reservoirs will be evaluated. Wellbore
strengthening techniques and the potential benefits of using such techniques will also be
presented. | en_US |
dc.language.iso | eng | en_US |
dc.publisher | University of Stavanger, Norway | en_US |
dc.relation.ispartofseries | Masteroppgave/UIS-TN-IPT/2010; | |
dc.subject | petroleumsteknologi | en_US |
dc.subject | boreteknologi | en_US |
dc.subject | drilling | en_US |
dc.subject | depleted reservoir | en_US |
dc.subject | Ula | en_US |
dc.title | Depleted reservoir drilling : a study of the Ula field in the North Sea | en_US |
dc.type | Master thesis | en_US |
dc.subject.nsi | VDP::Technology: 500::Rock and petroleum disciplines: 510 | en_US |
dc.source.pagenumber | 123 p. | en_US |