Conventionally, a well completion would involve perforating the reservoir followed by a separate run to clean up the wellbore from perforating debris and burrs on the casing and liner to prevent damage to the completion packer when passing through the perforated interval. This is especially prevelant in dual completion and single selective completion wells where the lower packer will have to be run past the upper set of perforations. The wellbore clean up bottomhole assembly typically consists of a drill bit scraper and magnets run between the perforating and well completion phases.
As a result of the increasing emphasis on reducing operating costs and increasing operating efficiency, a new system was designed for perforating wells in underballanced condition and performing post perforation wellbore clean up in the same run by using standard equipment and techniques. The concept was developed after identifying the opportunity to optimize operations in wells where the perforating and wellbore clean up equipment operations are required.
Five jobs have been performed employing this combined underballanced perforating and wellbore clean up technique which have resulted in significant savings in rig time and increased operating efficiency. This paper summarizes the practical experiences gained during the development and deployment of this integrated perforating and wellbore clean up technique.