FAQ: What Is A Subsea Wellhead?

The subsea wellhead system (Fig. 1) is a pressure-containing vessel that provides a means to hang off and seal off casing used in drilling the well. The wellhead also provides a profile to latch the subsea blowout preventer (BOP) stack and drilling riser back to the floating drilling rig.

What is the purpose of a wellhead?

The primary purpose of a wellhead is to provide the suspension point and pressure seals for the casing strings that run from the bottom of the hole sections to the surface pressure control equipment. While drilling the oil well, surface pressure control is provided by a blowout preventer (BOP).

How does a subsea well work?

The pipes allow a proportionate mixture of mud and water to flow through to enable the oil and gas trapped underneath, to be extracted and accumulate in the oil well. The oil is then collected and transferred accordingly.

What are subsea wells?

A Subsea well is a well in which all the production systems are located on the seabed. The facilities which are under water are basically referred to as ‘Subsea’. It can also be defined as a well drilled in an offshore location (within the sea). The prefix is used for wells, field, project and the development too.

What is wellhead system?

Wellhead systems serve as the termination point of casing and tubing strings. As such, these systems control pressure and provide access to the main bore of the casing or tubing or to the annulus.

What are the components of a wellhead?

Generally, the wellhead consists of three components: (1) the casing head, (2) the tubing head, and (3) the Christmas tree. The casing head consists of heavy fittings that provide a seal between the casing and the surface.

How much does a wellhead cost?

The average wellhead price of crude oil decreased $2.51 to $33.41 in September 2020 from August 2020. The monthly average price was $16.87 lower than the average price of $50.28 in the same month last year.

Why is subsea well?

Subsea well systems are among most profitable offshore projects, worldwide. They allow maximum use of infrastructure and developing reserves that are too small to be economic by other production systems. Start-up times short are now short – normally less than 2 weeks. System availability over 99% is common.

What does a subsea tree do?

Used on offshore oil and gas fields, a subsea tree monitors and controls the production of a subsea well. Fixed to the wellhead of a completed well, subsea trees can also manage fluids or gas injected into the well. Subsea trees are used in offshore field developments worldwide, from shallow to ultra-deepwaters.

What is a sea well?

The Seawell is a custom designed, dynamically positioned light well intervention and saturation diving vessel. Since 1987, the Seawell has been operating throughout the North Sea, providing subsea well intervention solutions and pioneering subsea Light Well Intervention (LWI).

What does subsea stand for?

Subsea is fully submerged ocean equipment, operations or applications, especially when some distance offshore, in deep ocean waters, or on the seabed.

What is a subsea engineer?

Subsea engineering is a multidisciplinary field that is broadly responsible for the control and direct flow of oil and gas from deep marine wells. The scope of this engineering field includes all hardware, control, umbilicals, pipelines and interfaces with host production facilities.

What is subsea service?

Subsea inspection and repairs of floating, storage and offloading (FSO) vessels and floating, production, storage and off-loading (FPSO) systems. Shallow and deepwater services of remotely operated vehicles (ROVs) All other underwater services related to the offshore industry.

What is a subsea manifold?

A manifold is an arrangement of piping and/or valves designed to combine, distribute, control, and often monitor fluid flow. Subsea manifolds are installed on the seabed within an array of wells to gather production fluids or to inject water or gas into wells.

What is the wellhead pressure?

Wellhead pressure – pressure at the top of the well, i.e., at its wellhead. It is measured by pressure gauges of the wellhead fittings. Numerically it equals the difference between reservoir pressure and hydrostatic pressure of the liquid column from wellhead to reservoir.

What is wellhead Control Panel?

Performing a safety critical function on manned and unmanned platforms, our Wellhead Control Panels (WHCPs) are designed for monitoring, controlling and shutdown of various subsurface and surface valves.