A rigid offshore drilling platform that stands on steel caissons and is used to drill development wells.
The caissons are firmly affixed to the seafloor, and the drilling and production decks are laid on top of them.
The platform is used in certain arctic waters, where the caissons are needed to protect equipment from moving ice.
See platform rig.
See filter cake.
One of the alkaline earth elements with a valence of 2 and an atomic weight of about 40.
Calcium compounds are a common cause of water hardness.
Calcium is also a component of lime, gypsum, and limestone.
A drilling method in which the hole is drilled by dropping a sharply pointed bit on bottom.
The bit is attached to a cable, and the cable is repeatedly dropped as the hole is drilled.
A jackup drilling unit in which the drilling rig is mounted on two cantilevers that extend outward from the barge hull of the unit.
The cantilevers are supported only at the barge end.
The character or state of the drilling mud filter cake.
From api rp 13b: notations such as “hard,” “soft,” “tough,” rubbery,” and “firm” may be used to convey some idea of cake consistency.
1.
A record showing variations in wellbore diameter by depth, indicating undue enlargement due to caving in, washing, or other causes.
The caliper log also reveals corrosion, scaling, or pitting inside tubular goods.
2.
A representation of the measured diameter of a borehole along its depth.
Caliper logs are usually measured mechanically, with only a few using sonic devices.
The tools measure diameter at a specific chord across the well.
Since wellbores are usually irregular (rugose), it is important to have a tool that measures diameter at several different locations simultaneously.
Such tools are called multi-arm calipers.
Drilling engineers or rigsite personnel use caliper measurement as a qualitative indication of both the condition of the wellbore and the degree to which the mud system has maintained hole stability.
Caliper data are integrated to determine the volume of the openhole, which is then used in planning cementing operations.
A special wrench designed for use in connecting the cage of a sucker rod pump to the sucker rod string.
A beam or beams that project outward from a structure and are supported only at one end.
1.a disk-like plate of anhydrite, gypsum, limestone, or sulfur overlying most salt domes in the gulf coast region.
2.
Impermeable rock overlying an oil or gas reservoir that tends to prevent migration of oil or gas out of the reservoir.
A chemical compound of calcium, sulfur, and oxygen.
Although sometimes considered a contaminant of drilling fluids, it may at times be added to them to produce certain properties.
Like calcium carbonate it forms scales in water-handling facilities, which may be hard to remove.
See gypsum.