How to change the oil seal of down-the-hole drilling rig

How does a drill rig work?

A drilling bit is attached to the end of a long string of jointed, hollow drill pipe, and the whole assembly is rotated by a motorized turntable at the surface, the rotary table. Modern rigs use a top drive system for rotating the drill pipe, an assembly that is guided up and down rails on the derrick. The rotating bit cuts or crushes the rock.

How do you drill a well?

The most common method of drilling wells uses rotary drilling (Figure 1). A drilling bit is attached to the end of a long string of jointed, hollow drill pipe, and the whole assembly is rotated by a motorized turntable at the surface, the rotary table.

What happens if a drill rig fails?

It should be dense enough to overbalance any high-pressure formations encountered while drilling. If it fails in this last action, the fluid in the formation will displace the mud up the hole. This is called a kick. Should this hazardous situation not be dealt with quickly, hydrocarbons will exit at the surface and a blowout results.

How can a downhole drilling tool failure be avoided?

Most downhole drilling tool failures and resultant fishing jobs can be avoided by the use of periodic inspections and by providing maintenance and repair to the primary fatigue areas of equipment. The primary areas of fatigue are locations on the tool that receive the highest concentration of stress while operating.

How do you straighten a hole in a drill?

One of the most common techniques for straightening a hole is to reduce the weight on the bit and increase the rotary table or top-drive speed. By reducing the weight on the bit, the bending characteristics of the drillstring are changed and the hole tends to drill straighter.

How to prevent crooked holes in a straight hole drilling contract?

In a straight hole drilling contract, many of the possible crooked hole troubles can be prevented by obtaining satisfactory contract terms on deviation and doglegs. It is extremely important, when negotiating the contract, that the operator be aware of the advantages of giving the broadest possible limits for hole deviation.