Low-pressure wellhead for high-pressure stimulation
Maturity of US Producing wells and constrained economics dictate careful planning and strict attention to details to optimize workover and recompletion operations. One aspect of operations that can significantly reduce costs is planned preparation of a wellheat for high-pressure stimulation. Historically, there have been four basic approaches to solving old wellhead configuration problems to prepare for high-pressure stimulation down casing. Some recent technical developments may provide a lower-cost solution. A casing spool is now available that features an external casing seal that cannot be pumped out. This seal is extremely reliable and has functioned on many extreme-pressure (15,000-psi) jobs without a single failure. Having the seal installed in a frac spool'' is very important because it provides convenient adaption from the low-pressure casing hanger to high-pressure control equipment with safety and reliability. Casing hanger seals are isolated from the harsh stimulation environment. While the newly available spool discussed above provides a partial solution to the low-pressure-wellhead/high-pressure-stimulation problem, valve performance must also be considered. Recent improvements in gate-valve design have produced a valve that meets all required performance criteria for efficient stimulation operations. The new frac valve'' features low maintenance with close tolerances on gate/seal surfaces, low operating torque, high corrosion and erosion resistance, sealing in both directions, and generally high performance in functionality.
- OSTI ID:
- 7111921
- Journal Information:
- JPT, Journal of Petroleum Technology; (United States), Vol. 46:5; ISSN 0149-2136
- Country of Publication:
- United States
- Language:
- English
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