Laboratory and field evaluation of a two-component polyurethane foam for lost circulation control
A two-part polyurethane foam supplied by Poly Plug, Inc., has been tested in the laboratory and in the field to assess its utility in controlling lost circulation encountered when drilling geothermal wells. A field in The Geysers was conducted, based on earlier laboratory work that showed the foam c...
| Main Authors: | , , , , |
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| Language: | unknown |
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2020
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| Subjects: | |
| Online Access: | http://www.osti.gov/servlets/purl/7229299 https://www.osti.gov/biblio/7229299 https://doi.org/10.2172/7229299 |
| Summary: | A two-part polyurethane foam supplied by Poly Plug, Inc., has been tested in the laboratory and in the field to assess its utility in controlling lost circulation encountered when drilling geothermal wells. A field in The Geysers was conducted, based on earlier laboratory work that showed the foam chemical formulation to be capable of expanding under elevated temperatures and pressures to form a rigid, impermeable polymer that should be effective in plugging fluid-loss zones. Although the downhole tool used to deploy the foam chemicals apparently functioned properly in the field test, the chemicals failed to expand significantly downhole, instead forming a dense polymer that may be ineffective in flowing into and sealing loss zones. Subsequent laboratory tests were conducted under simulated downhole conditions to determine the cause of the polymer's failure to sufficiently expand. The results indicate that the foam chemicals undergo vigorous mixing with water in the wellbore, which disturbs the kinetics of the chemical reaction more than was previously contemplated. The results indicate that without significant changes in the foam chemical formulation or delivery technique, the existing foam system will be ineffective in lost circulation control except under very favorable conditions. 6 refs., 46 figs., 7 tabs. |
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