What is a subsea well?

1. n. [Well Completions] A well in which the wellhead, Christmas tree and production-control equipment is located on the seabed.

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.

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 subsea stand for?

Systematic Underwater Biogeochemical Science and Exploration Analog
The project pulling together ocean and space is called SUBSEA, which stands for Systematic Underwater Biogeochemical Science and Exploration Analog.

How many subsea wells are there?

In 2014, 328 subsea wells worldwide came onstream or started achieving first production. A subsea well startup refers to the initial operational commencement of a subsea well….Total number of subsea well startups worldwide from 2010 to 2017*

What is a subsea tree?

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 subsea well intervention?

Subsea well intervention system is deployed from the work deck of a service vessel. It consists of an integrated set of pressure-contained subsea packages compromising well control package (WCP), tool storage package (TSP), wireline winch package (WWP), and fluid management package (FMP).

What is subsea equipment?

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

How much does it cost to drill an offshore oil well?

From 1998 to 2019, exploration and delineation drilling cost averaged $90.9 million per well and $26,494 per meter drilled. Development wells drilled from mobile offshore drilling units over the same period averaged $91.1 million per producer well and $68.8 million per injector well.

How many offshore oil wells are there?

more than 12,000 offshore oil and gas platforms worldwide. As they drain their reservoirs of fossil fuels below the sea, they eventually become defunct when they produce too little fuel for extraction to be profitable to their operators.

What is the difference between wellhead and Christmas tree?

Many times, the words Christmas Tree and Wellhead are used interchangeably; however, a wellhead and Christmas tree are entirely separate pieces of equipment. A wellhead must be present in order to utilize a Christmas tree and is used without a Christmas tree during drilling operations.

What is the difference between surface well and subsea well?

Offshore surface well = dry tree. Subsea well = wet tree. A dry tree has its wellbore extended vertically up all the way to the host platform. The tree with its various valves and choke is placed at the platform. The wellbore can be directly accessed from the topsides for interventions.

What is a subsubsea well?

Subsea well = wet tree. A dry tree has its wellbore extended vertically up all the way to the host platform. The tree with its various valves and choke is placed at the platform. The wellbore can be directly accessed from the topsides for interventions. There directly translates to lower OPEX (operational expenditure).

What is the typical size of a subsea wellhead?

Fig. 1—Illustration of a typical subsea wellhead system with temporary abandonment cap installed. This illustration also shows the wellhead configuration with a 30 × 20 × 13⅜ × 9⅝ × 7-in. casing program. The subsea wellhead inside diameter (ID) is designed with a landing shoulder located in the bottom section of the wellhead body.

What is the difference between deepwater drilling and offshore drilling?

Deepwater drilling is a subset of Offshore drilling. Everything that is not on the land is classified as offshore drilling while deepwater is defined based on the depth of water in which the drilling is undertaken. This depth is 5000 ft.