D. Drilling rig classification

There are many types and designs of drilling rigs, depending on their purpose and improvements; many drilling rigs are capable of switching or combining different drilling technologies. So they are classified

1) by power used:

electric - rig is connected to a power grid;

mechanic - rig produces power with its own (diesel) engines;

hydraulic - most movements are done with hydraulic power;

pneumatic - pressured air is used to generate small scale movements;

2) by pipe used:

cable - a cable is used to slam the bit on the rock (used for small geotechnical wells);

conventional - uses drill pipes;

coil tubing - uses a giant coil of tube and a downhole drilling motor;

3) by height:

single - can drill only single drill pipes, has no vertical pipe racks;

double - can store double pipe stands in the pipe rack;

triple - can store stands composed of three pipes in the pipe rack;

quad - can store stands composed of four pipes in the pipe rack;

4) by method of rotation:

no rotation (most service rigs);

rotary table - rotation is achieved by turning a square pipe (the kelly) at drillfloor level;

top-drive - rotation and circulation is done at the top of the drillstring, on a motor that moves along the derrik;

5) by position of derrick:

conventional - derrick is vertical;

slant - derrick is at an angle (this is used to achieve deviation without an expensive downhole motor).

Дата добавления: 2015-07-21