Several attempts to enter the upper lateral of a multilateral well operated by a major oil company in Alaska had been unsuccessful. In May 2017, an ultrasonic imaging technique based on medical ultrasound imaging was used to inspect the lateral-entry modules (LEMs). This paper presents the data collected by an ultrasound downhole scanner, demonstrating a novel method for diagnosing multilateral wells.
Background
The West Sak field is a viscous-oil deposit within the Kuparuk River Unit on the Alaskan North Slope. The reservoir was deposited in a lower shoreface to inner-shelf marine environment and consists of highly unconsolidated sandstones that have a gross thickness of approximately 500 ft and an average net thickness of 90 ft. The reservoir consists of three major producing intervals, the West Sak D, B, and A sands.
Since original development in 1997, West Sak has been an active waterflood site.