brønnhode

Brønnhode is a surface equipment at the top of a borehole, used in oil and gas wells to seal, suspend, and provide a pressure boundary and access to the well for drilling, testing, and production. It serves as the mechanical and pressure-containing interface between the borehole and surface facilities.

It typically comprises a casing head, tubing head, and a spool with valves and outlets. The casing head attaches to the upper end of the casing strings and provides a seat for hangers. The tubing head provides a connection point for production tubing and houses hangers for the production casing. The wellhead includes valves or choke and test connections, and enables installation of a wellhead tree or production tree on top, through which fluids are controlled.

Types include surface wellheads, used onshore or on offshore platform topsides, and subsea wellheads, mounted on the seabed and connected to pipelines via a subsea tree and a riser. The subsea system includes a subsea wellhead housing that anchors to the wellbore and provides a mounting for the subsea tree and control lines.

Standards and safety considerations: wellheads are designed to withstand high pressures and loads, typically following API 6A for wellhead equipment, with regulatory compliance in respective jurisdictions. Materials are high-strength steel alloys with corrosion resistance, and operations involve testing and regular integrity checks.

In practice, the brønnhode is essential for drilling and production, providing reliable isolation, pressure containment, and a interface for downstream equipment used in extraction.