Improving Swell Packer Performance Through Standardized Qualification Process

Abstract Swell packers have been used for decades as openhole zonal isolation for conformance control and/or stimulation treatments. API19OH dictates how to qualify swell packers and perform differential pressure testing once fully set. Currently there is no standard for predicting swelling performance. This would increase success rate of casing/liner runs and time predictions for achieving the required zonal isolation. It is difficult to evaluate actual swelling performance and zonal isolation effectiveness of swell packers once run in hole. There is limited information available in literature. In this paper, we will review field data that initiated further investigation. Working with suppliers information was collected to better understand 1) how to qualify the raw material, 2) how to qualify the cured rubber element and 3) how to predict the swelling rate. Actual swell performance data was obtained when a liner was pulled due to a liner hanger failure. It showed that 1) the swelling model prediction was not accurate, and 2) the swelling speed had a wide variance. The initial investigation revealed that the qualification process of the raw material and the cured rubber element is consistent among the suppliers. All suppliers perform durometer measurements. Further investigation found that each supplier had their own recipe for their rubber compound, however, testing methods differed to develop their swelling model which changed the prediction results. This suggests the industry should define a standard testing method to improve the swelling performance, including validation of repeatability, to compliment API19OH. Reliable and effective zonal isolation is critical for openhole multi-zone completions. Currently, the industry has a gap in prescribing swell performance test methods that can benefit packer performance in wells.