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Photo by: Geir Ove Titlestad
Above: The return at the surface from the cement during P&A activities
Plugging and
abandonment
(P&A)
and
related
well
tests
During P&A the same telescopic work strings are employed for pressure testing and for administering the water and
cement. The HW string is often left in the well and plugged in the same way as the drill hole its self.
7. Plugging and Abandonment (P&A) and related well tests
If CO2 is to be captured, injected and stored into the tested sand formation in the future, it is essential to plug the
test wells so that potential captured and stored CO2 cannot escape, migrate or leak out of the “dedicated” storage
formation. Accordingly, all wells have to be plugged so there is no uncontrolled flow of gas and fluid to the surface or
between permeable formations. In order to comply with the forwarded by the Petroleumstilsynet (PTIL) for P&A of
the Unis Well Park in Advendalen and Wells DH1&2 in Hotellneset, and P&A program has been made:
The set standard is:
“All wells must be plugged in accord to the regulations applicable for the oil and gas industry”.
The set standard is:
“
All wells must be plugged in accord to the regulations applicable for the oil and gas industry”.
Three of the wells in the well park contain significant amounts (compared to the other wells in the area) of natural
gas. Further, two of the wells have a shallow water flow/production from the Festningen sandstone at ca 180 m depth.
Due to the extensive plugging program, project partners have been involved with discussion around technical as-
pects and economic challenges. The final P&A of the wells will render them inaccessible in the future. Accordingly,
tests in individual wells have to come to completion before P&A could take place.
Figure left: cross section plugging
The Longyearbyen CO2 Lab’s P&A program and operations have followed the NOR-
SOK D-010 standard (NORSOK D-010 standard, section 9). The main philosophy is
to establish two barriers (primary and secondary barrier) above the sand formation
that potentially will be used for CO2 storage and can be potential leak out of the
storage formation. The wells were plugged for the entire cross sectional area – ac-
cording to the figure to the left.