What are the Commonly Used Drilling Tools in Petroleum Exploration?

Petroleum exploration is a difficult project. Many tools are needed during petroleum exploration, and drilling tools are one of the common tools. Thus, what is the commonly used drilling tools in petroleum exploration? Let me introduce them to you:

1. Kelly

The kelly is located at the uppermost end of the drill string, and its main function is to transmit torque and bear the total amount of the drill string. The end face of the driving part of the kelly is divided into a square and regular hexagon. The square end face is mostly used in oil drilling, and the regular hexagon end face is mostly used for the water eye. Because the wall thickness is about three times thicker than that of the drill pipe, and it is made of high-strength alloy steel, the kelly has high tensile strength and torsional strength.

2. Drill pipe

Drill pipe is the basic component of the drill string, it is mainly used to transmit torque and transport drilling fluid. The pipe body that currently in use and the joint of the drill pipe is connected by butt welding. In order to increase the strength of the joint, the butt welding parts at both ends of the pipe body are thickened. There are three types of thickening methods: inner thickening, outer thickening, and inner-and-outer thickening.

3. Extra-weight drill pipe

The characteristic of the extra-weight drill pipe is that its wall thickness is more than twice that of the ordinary drill pipe, the joint body is longer than the ordinary drill pipe, and there is a special wear roller in the middle of the pipe body.

4. Drill collar

The drill collar is one of the main components of the drill string. Its function is to provide the drill bit with bit pressure, and at the same time make the lower drill tool assembly have greater rigidity so that the drill bit could work stably and help to overcome the good deviation problem.

5. Spiral drill collar

The function of the spiral drill collar is to reduce the occurrence of sticking and bit jamming. Three right-handed spiral grooves are machined on the outer cylinder of the round drill collar. There is a 305-560mm round drill collar section with no grooving in the external screw joint part, and a 475-610mm round drill collar section with no grooving on the internal screw end joint. Therefore, its weight is 4% less than that of round drill collars of the same size.

6. Stabilizer

1) Stabilizers are commonly known as centralizers. A certain number of stabilizers are placed in a suitable position in the drill string to form the lower drilling tool assembly of the drill string, which can prevent well deviation when drilling straight wells, and control well trajectory when drilling directional wells.

2) The use of stabilizers can improve the working stability of the drill bit, thereby prolonging the service life of the drill bit, which is particularly important for diamond drill bits.

7.  Non-magnetic drill collar

The structure of non mag drill collars are as same as that of ordinary drill collars, but their chemical composition and mechanical features are different from ordinary drill collars. Non-magnetic drill collars are drilling tools with special functions in directional good engineering. When measuring the inclination angle and azimuth angle of the borehole with a magnetic inclinometer for directional wells, in order to prevent the compass from being affected by the magnetic field of the drill string, a certain length of non-magnetic drill collar must be equipped in the drill string so that the magnetic inclinometer could be fixed in the right position to work. Otherwise, the correct measurement result cannot be obtained.