ESIPC, Cement Assurance Tool and C-Flex; After evaluating the ranking values of the different options, the best one would be to combine the ESIPC, Cement Assurance Tool and the C-Flex with the drilling liner. This option got the highest ranking score, mainly because it can guarantee a higher injection pressure every time, the theoretical effect of the integrity is quite high, and the operation lifetime would be at least as long as the well itself due to a higher injection pressure. Some lower score is given because of the unknown cost and feasibility on the integrity, but it would be a very good solution to provide a good barrier at the top of Tor formation. How well this option could handle a contingency situation is unknown as well because it needs redesigning. The Cement Assurance Tool would provide extra insurance in case if there should be a leak past the packer in the ESIPC, which gives a better operation lifetime. The squeeze job through the C-Flex gives a better operation lifetime but has an extra cost.
ESIPC and C-Flex;
This option came in second. The difference between this option and the first one above is the Cement Assurance Tool. This option could give a less operation lifetime if a leak through a micro- annulus occurs, but still has the C-Flex and an extra cement squeeze job is possible.
ESIPC;
This option came in third. The difference between this option and the second one is the C-Flex port collar. This option gives a lower cost, but could give a less operation lifetime if a leak through a micro-annulus occurs. In addition it has not the ability to do an extra cement squeeze job.
Shale Annular Barrier, Cement Assurance Tool and C-Flex;
This option came in fourth. This option ranked high because of the theoretical effect on integrity, operation lifetime, and the ability to handle a contingency. Some lower score is given because it cannot guarantee a higher injection pressure every time, and the feasibility of the integrity is average because there is no guarantee that the shale provides a proper seal. The Cement Assurance Tool would provide an extra insurance in case a leak should pass the cement. In these cases, the Cement Assurance Tool along with the cement squeeze job through the C-Flex gives a higher feasibility of the integrity. The pressure test and logging would give a large extra cost, and has to be taken into account.
Shale Annular Barrier and C-Flex;
This option came in fifth. The difference between this option and the fourth one is the Cement Assurance Tool, which could in this case give a lower feasibility on the integrity. The pressure test and logging would give a large extra cost, and has to be taken into account.
Cement Assurance Tool and C-Flex;
This option came in sixth. The reason for this rank is because the feasibility of the integrity is quite good along with the ability to handle a contingency. It scored average on its ability to increase the injection pressure and the theoretical effect on the integrity.
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ThermaSet and C-Flex;
This option came in seventh. The reason for this rank is because the ThermaSet cannot guarantee a better barrier than cement and increase the injection pressure.
Swellpacker and C-Flex;
This option came in eighth. The reason for this rank is because the Swellpacker cannot guarantee an increased injection pressure, and is not applicable in a contingency situation. The squeeze job through the C-Flex gives in this case an average theoretical effect on the integrity.
Swellpacker;
This option came in ninth. The difference between this option and number eighth is the C-Flex port collar, and gives a lower theoretical effect on the integrity.
Shale Annular Barrier;
This option came in tenth. The reason for this rank is because there are no guarantees that the shale would collapse around the liner, even after some years. When there is nothing to “help” the shale sealing the annulus, there is no guarantee that the injection pressure can be increased. The theoretical effect on the integrity and feasibility is bad as well.
C-Flex and Foundation;
This option came in eleventh. The reason for this rank is because the foundation would not prevent the cement from being squeezed into the reservoir if there is a communication, and can’t be used in a contingency situation.
Expandable Liner Hanger;
This option came in twelfth. The reason for this rank is because it offers no direct solution to increasing injection pressure because it is placed at the top of the liner while the barrier challenge is at the bottom of the liner. The theoretical effect on the integrity is therefore very bad. The feasibility, the operation time, installation and the cost were good.
DuraWAV;
This option came in thirteenth. The reason for this rank is because it offers no direct solution to increasing injection pressure.
Expandable Liner;
This option came in last. The reason for this rank is because it cannot be included in a drilling liner in a way that it could increase the injection pressure. The theoretical effect on integrity is very bad.
97