How does a heave compensator work?

Heave compensator is a system that mitigates transmission of heave movement from ves- sels to the equipment in the vessel. Heave compensator attenuates movement transmitted from the vessel to the drill string and drill bit ensuring security and efficiency of the offshore drilling process.

What is a downhole heave compensator?

Both passive and active heave compensators are installed in the derrick to reduce the effects of vertical ship motion (heave) on the drill string and coring tools. Benefit: Both heave compensators allow coring from a heaving vessel, extending the opera- tional weather window and improving core recovery and quality.

How does a motion compensator work?

A motion compensator is a device that decreases the undesirable effects of the relative motion between two connected objects. Not only does the anchor prevent the ship from drifting, but the chain itself dampens the movement of the ship due to undulating motion of the waves.

How does a drill string compensator work?

A drill string compensator decreases the influence of the heave of a drilling vessel on the drill bit. Drill string compensators are used onboard drill ships and semi-submersible drill rigs. There are two major types of drill string compensators: Drill string compensator between the traveling block and hook .

Why do we have motion compensation on the rigs?

Top-mounted motion compensation system. Cameron motion compensation equipment for drillstrings and risers enables floaters to operate in the harshest environments by compensating for relative movement between the drilling vessel and seabed. Maintain the production riser system in tension.

What is heave sensor?

The IMU range provides high accuracy motion measurement data in dynamic environment in all areas from small hydrographic vessels to large oil rigs in all weather conditions. The IMU-106 is a cost effective heave motion sensor. It is typically used in applications like single beam sonars, crane and winch compensation.

What is heave data?

Heave data are records of the vertical motion of the platform. In Echoview, a positive heave value (from the heave line) represents downward motion. The heave at any time along the heave line is calculated by interpolating between the two nearest adjacent line points.

How do you calculate heave?

Po = overburden stress plus the vertical stress from foundation loading on nth layer. The surface heave can also be calculated as the area under percent swell SLi versus depth curve, as illustrated in Fig.

What is a heave sensor?

What causes heave?

What causes heave? Heave is usually the result of clay soils expanding due to an increase in moisture levels. Clay is what is called an ‘expansive soil’. This means that when it is wet it expands and when it becomes dry it shrinks.

What is the difference between heave and subsidence?

What is subsidence and what is the difference between subsidence and heave? Subsidence is the downward movement of those foundations, whereas heave is the upward. Both can cause internal and external issues, as a property sinks or shifts in response to impacts on the earth beneath.

What are the signs of heave?

Common signs of ground heave may include:

• Cracking to brickwork and windows. This cracking is more likely to be vertical, whereas subsidence cracking is more likely to be diagonal.
• Doors sticking as their frames become out of square.
• Lifting of paths and patios surrounding buildings.