New Bridge Plug and Retrieving Tool that Aids Completion of Geothermal Steam Wells
A typical completion procedure requires placement of a bridge plug near the liner top of a producing steam well so the well can be loaded to permit cementing of the tieback casing string by conventional cementing techniques. A drillable bridge plug has been used in the past so that it could be removed with a conventional toothed, cone-type drill bit. All components could not be drilled out because the bridge plug would separate from the casing when drilling through its top slips. This created a hazardous situation because heavy components remaining in the well could blowout after placing the well into production and damage or destroy surface equipment. A bridge plug and its companion milling-type retrieving tool were developed to perform the bridging operation and accomplish removal in a producing geothermal steam well environment. The bridge plug features an internal briding plug that is designed to permit the release of differential pressure buildup from below before releasing the bridge plug by milling away the top slips. The millinog-type retrieving tool has a catcher mechanism designed to function in the high-velocity steam flow of a producing well to catch the released bridge plug. After the released bridge plug components are caught, they may be returned to the surface in a controlled manner. This removes the massive components so that they will not be blown out by the steam of a producing well. Field use has demonstrated that this equipment is a practical completion aid, and it is currently being used in The Geysers field of northern California. Examples of field usage are discussed in the paper.
- Research Organization:
- DOEEEGTP (USDOE Office of Energy Efficiency and Renewable Energy Geothermal Tech Pgm)
- DOE Contract Number:
- AC04-76DP00789
- OSTI ID:
- 886118
- Report Number(s):
- SAND-81-0036C; CONF-810105-18; TRN: US200616%%997
- Resource Relation:
- Conference: International Geothermal Drilling and Completions Technology Conference, Albuquerque, NM, USA, 21 Jan 1981
- Country of Publication:
- United States
- Language:
- English
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