How does a riser tensioner work?
Cameron wireline riser tensioners are available in three versions—160,000-lbf, 200,000-lbf, and 250,000-lbf double-wire rope tensioners. Their design includes idler sheaves, wire, rotating deadline drum, valve block skids, air pressure vessels (APVs), control system, antirecoil, and optional air compressors.
What is the capacity range for a riser tensioner system?
Typically, the system is designed for a maximum static vertical load of up to 4,800 kips at well center, and sliding with 1,600 kips. The tensioners are attached to sliding plates which ride on composite bearing material.
What is a riser in drilling rig?
The risers are pipes through which the drill string carries out the drilling function. A marine drilling riser system provides a tubular conduit from the drilling unit to the subsea blow out preventer (BOP) and the wellbore below it. The drilling riser is composed of a series of joints which are connected by couplings.
What are the two interfaces for a drilling riser?
Drilling risers are categorised into two types: marine drilling risers used with subsea blowout preventer (BOP) and generally used by floating drilling vessels; and tie-back drilling risers used with a surface BOP and generally deployed from fixed platforms or very stable floating platforms like a spar or tension leg …
Why is it important to know the minimum top tension?
Minimum tension is established to prevent buckling of the riser. Maximum tension is established to prevent top tensions in excess of the installed capacity of the riser.
What is riser in offshore?
some of the offshore operations that riser systems are used to. facilitate: • Drilling operations from fixed platforms, jackups, floating drilling platforms, and floating production. facilities.
What is a subsea riser?
Subsea risers are developed for transportation of products from the seafloor to production and drilling facilities at the sea surface, as well as from the facility to the seafloor.
What is riser on offshore rig?
Marine risers are cylindrical conduits that are used to transfer crude oil from the subsea wellhead to the offshore facility. A combination of a variety of environmental loads that arise from waves, current, and those arising from the impact of vessels shall result in the development of extreme stresses.
What does Riserless drilling mean?
“Riserless drilling” does not use Riser pipe. Instead, in “Riserless drilling”, the drillpipe runs into the open water to the sea floor and into the borehole. Here, seawater is used as drilling fluid. The cuttings are not returned to Chikyu and are washed out of the borehole onto the sea floor.
What is subsea riser?
Subsea Production Risers An SCR is a free-hanging riser with no intermediate buoys or floating devices. TTRs are used as conduits between dynamic floating production units and subsea systems on the seafloor, for dry tree production facilities such as spars and TLPs.
What is subsea umbilicals risers and flowlines?
Flowlines transport unprocessed fluids from the subsea well to the riser. The riser then transports the fluids to the surface processing system. They provide transportation of the production fluid, as well as transporting injection fluids, control fluids and gas lift to the subsea system.
What are the types of riser?
Types of riser
- Dry riser: Used to supply water within buildings for fire-fighting purposes.
- Wet riser: Used to supply water within buildings for fire-fighting purposes.
- Stairs riser: The vertical face between the back of the tread of one stair and the front of the tread of the stair above.
What are subsubsea risers used for?
Subsea risers are used in both jack up and semi-submersible drilling operations, however their design and configuration is quite different between the two modes of drilling – dependant on a variety of factors including; depth, current strength, wave frequency and height.
What is the riser tension?
The riser tension is the single most important parameter in the operation of a drilling riser. Every time the mud weight is changed, the riser tension must also be changed. As operating water depths increase, the importance of the marine drilling riser has grown.
Why choose Claxton for your subsea riser project?
Our engineering excellence and riser design capability provide an integrated approach to subsea risers. Claxton has been designing, building and installing complete subsea riser systems since 1999 and our experience means that we are able to meet the needs of challenging projects within short lead times.
What is a drilling riser?
A drilling riser is a conduit from a subsea well to the surface, used in offshore drilling operations that acts to provide three critical functions: A temporary extension of the well architecture – essentially an environmental barrier, providing pressure containment and well-control.