This paper presents field data from the successful use of an in-situ polymerisation water shutoff system in a hot (147 C), high productivity, high rate, well. Previously the chemical system had not been applied above 93 C or in such a prolific well. The job was performed by a team comprising the operator and two service companies. One service company supplied the selected chemical technology. The other service company supplied the means to deploy the system with the control of placement the job demanded. The success of the treatment resulted from a combination of factors. The job design ensured that oil production from the well would not be harmed even though complete mechanical isolation of the oil-producing zone within the wellbore could not be guaranteed. To ensure the oil-producing zone was not damaged, coiled tubing and packer placement was combined with dual injection to protect the oil. Wellbore and reservoir modelling of the pre-cool and gelant injection was used to estimate the required injection rates and volumes. Laboratory studies used field materials, and field conditions were used to check blocking times and possible problems. The pre-cool design was checked and enhanced by a pre-job injection trial.
Monitoring temperature and the pressure above and below the packer during the actual job allowed highly controlled "live" amendments to the injection regime.
The Ula field lies in Block 7/12 of the Norwegian Sector of the North Sea (see Figure 1).
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