Unitized wellhead system
A unitized wellhead system is described, comprising a wellhead housing having a bore there through with a seat about the bore and vertically spaced upper, intermediate and lower side outlets from the bore above the seat, a first hanger mandrel adapted to land in the housing bore above the seat for suspending a first casing therefrom, means for sealing between the first casing hanger mandrel and the bore of the housing between the intermediate and lower outlets so as to fluidly connect the lower outlet with the annulus between the first casing and an outer casing, a second hanger mandrel adapted to land in the bore above the first hanger mandrel for suspending a second casing within the first casing and having a seat about its bore and a side port connecting with its bore above its seat, means for sealing between the second hanger mandrel, and the housing bore above and below the upper outlet from the housing as well as above and below the side port in the second mandrel so as to fluidly connect the intermediate outlet with the annulus between the first and second casings, when the second casing is suspended from the second hanger mandrel, a third hanger mandrel adapted to land on the seat on the second mandrel so as to suspend tubing within the second casing, when the second casing is suspended from the second mandrel, and within the first casing, when the second casing is not suspended therefrom, and means for sealing between the third hanger mandrel and second hanger mandrel above the side port in the second hanger mandrel so as to fluidly connect the port in the second hanger mandrel and thus the upper outlet from the housing with the annulus between the tubing and the second casing, when the second casing is suspended from the second hanger mandrel, and the annulus between the tubing and first casing, when the inner casing is not so suspended.
- Assignee:
- Dril-Quip, Inc., Houston, TX (United States)
- Patent Number(s):
- US 5236037; A
- Application Number:
- PPN: US 7-817291
- OSTI ID:
- 6230503
- Resource Relation:
- Patent File Date: 6 Jan 1992
- Country of Publication:
- United States
- Language:
- English
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