Superhard materials from powder

advantage n — преимущество mould n — форма, опока

article n — изделие powder n — порошок

coating n — покрытие recognize v — признавать

double v — удваивать reliability n — надежность

furnace n — печь sinter v — сплавлять

grain n — зерно spray v — распылять

layer n — слой worn-out. — зд. изношенный

The development of a number of industries is unthinkable without materials with special properties. Powder metallurgy helps to obtain such materials.

The operational principle of powder metallurgy is very well known — an article of necessary size is modelled, in a mould, out of very small metal grains and is put into an electrothermic furnace where the grains get sintered together.

The coefficient of the use of metal grows by five times and the time of operation of powder articles increases greatly. The sintered articles have already shown their advantages in outer space, in deep sea condi­tions and inside various machines. The antivibration alloys of the "iron-copper" type made it possible to double the life of drilling tools. This increased the labour productivity by 20 per cent.

Russian scientists were the first to develop a new superhard material out of boron nitride. The priority of Russia in developing the first article out of so-called viscous ceramics has been recognized in many countries. There is another method when powder is sprayed onto the worn-out metal parts. The spraying of powder on articles made of usual steel makes them highly heat-resistant and much stronger. Their reliability and length of service increases. The powder is pressurized, melted and sprayed in a thin layer on different metal parts. Such a coating saves metal from corrosion for a period of 25 years.

RIG EQUIPMENT.

The equipment associated with a rig is to some extent dependent on the type of rig but typically includes at least some of the following items

Anchors - hold a mobile offshore drilling rig in place while drilling is taking place.

Drilling Rig - cover an incredibly diverse range depending on the type of drilling rig. They are often very precisely engineered and carefully machined and speced for each specific application. They can be symmetric, asymmetric, measured from millimeters to meters in diameter, be high speed, low speed, work with air, fluids or dry.

Drill Casing and Drill Rods -- like drill bits are specifically tailored to the type of rig, bit and other parameters of the drill rig and process. They are also made to close tolerances regarding the dimensions, materials, hardening, treatments and the (often) proprietary threading and/or connectors used.

BOPs (Blowout preventers) -- are pieces of equipment installed at the wellhead to control pressures and fluids during drilling and completion and in particular to quickly close a well when something goes wrong in order to prevent spillage of mud, oil and/or flammable gas.

Boilers, bales -- hoops used to lift on the drill rods or casing they are threaded on and typically hooked on to the rig cable hoist system for lifting.

Centrifuges -- separate fine silt and sand from drilling fluid.

Chain tongs -- wrenches used to tighten pipe, composed of a length of chain attached to a handle with an outwardly-toothed open jaw. The chain is wrapped around the pipe and fixed back on the jaw, the chain grips the pipe against the jaw teeth while the handle is used as a lever to turn the pipe. These come in a variaty of sizes as required and are powered either manually or hydraulically.

Degassers -- separate gas from drilling fluid so that the mud can be safely re-used.

Elevators -- similar to bales, rather than threaded on, these are split collars which are placed around the drill rod or casing couplers and used for lifting.

Hydrocyclones -- separate fine silt and sand from drilling fluid.

Mud motors, Mud pits -- store drilling fluid until it is required down the wellbore and to allow sand and silt to settle out before reuse.

Mud pumps -- pump drilling mud or cement through the system.

Shale shakers -- separate coarse drilling cuttings from the drilling mud before it is pumped back down the borehole.

Rotary Table -- rotates the drill bit attached to a string of drill pipe joints.

Draworks -- Used to pick up and lower the drill string. Also used to control the weight on the Drill bit, and hence control rate of penetration (ROP).

Drill Pipe -- They are joints of pipe used to connect the drill bit. They also act as a conduit for drilling mud, to cool off the drill bit, bring cuttings up to surface and balance down hole pressures. Drill pipes come in various sizes (diameters) the lengths are usually around 30', pressure ratings, and grades.

Date: 2015-09-24; view: 2097; Нарушение авторских прав