Hybrid wellhead system and method of use
AssigneeStinger Wellhead Protection, Inc.
InventorsBob McGuire, L. Murray Dallas
Life of this patent
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Abstract
A hybrid wellhead system is assembled using a plurality of threaded unions, such as spanner nuts or hammer unions, for securing respective tubular heads and a flanged connection for securing a flow control stack to a top of a tubing head spool. The tubing head spool is secured by a threaded union to an intermediate head spool. The intermediate head spool is secured by another threaded union to a wellhead. Each tubular head secures and suspends a tubular string in the well bore. The hybrid wellhead system is capable of withstanding higher fluid pressures than a conventional independent screwed wellhead, while providing a more economical alternative to a flanged, or ranged, wellhead system because it is less expensive to construct and faster to assemble.
Claims21
A hybrid wellhead system, comprising:
- a plurality of tubular heads connected together using threaded unions to form the hybrid wellhead system, each tubular head supporting a tubing mandrel for suspending a respective tubular string in a well, each tubing mandrel having a top end that extends above a top of the tubular head that supports it;
- and
- a tubing head spool mounted to a top one of the tubular heads, the tubing head spool having a bottom end with an outer shoulder that is engaged by a threaded union for connecting the tubing head spool to the top one of the tubular heads, the tubing head spool supporting a tubing hanger that is locked in place and the tubing head spool further having a flanged top end for connection of a flow-control stack.
A method of installing a wellhead for stimulating a well for the extraction of hydrocarbons therefrom, where fluid pressure may exceed a working pressure rating of an independent screwed wellhead to be installed on the well, the method comprising:
- securing a plurality of tubular heads together to form a hybrid wellhead system using threaded unions, each tubular head suspending a respective tubular string in the well, each of the successive tubular heads having a higher working pressure rating than a tubular head to which a bottom end of each respective tubular head is secured;
- mounting a tubing head spool to a top one of the tubular heads, the tubing head spool having a bottom annulus which includes an outer shoulder that is engaged by a threaded union for connecting the tubing head spool to the top one of the tubular heads, the tubing head spool supporting a tubing hanger and having a flanged top end for connection of a flow-control stack.
Dependencies are inferred from the claim text.