Drill string

At each end of the drill pipe, tubular larger-diameter portions called the tool joints are located.

Modern onshore rigs are capable of handling ~90 ft stands (often referred to as a triple).

The mechanical success of cable tool drilling has greatly depended on a device called jars, invented by a spring pole driller, William Morris, in the salt well days of the 1830s.

Later, using jars, the cable tool system was able to efficiently meet the demands of drilling wells for oil.

The jars were improved over time, especially at the hands of the oil drillers, and reached the most useful and workable design by the 1870s, due to another patent received in 1868 by Edward Guillod of Titusville, Pennsylvania, which addressed the use of steel on the jars' surfaces that were subject to the greatest wear.

In the case of jarring up above a stuck bottom hole assembly, the driller slowly pulls up on the drillstring but the BHA does not move.

After a few inches of movement, this moving section slams into a steel shoulder, imparting an impact load.

Jars are designed to be reset by simple string manipulation and are capable of repeated operation or firing before being recovered from the well.

At shallow depths jar impact is not achieved because of lack of pipe stretch in the working string.

Early patents and teaching attempted to explain the process and mechanism involved, but lacked a certain degree of sophistication.

Mr. Bodine introduced the concept of resonant vibration that effectively eliminated the reactance portion of mechanical impedance, thus leading to the means of efficient sonic power transmission.

The cited work involving liner, tubing, and drill pipe extraction and was very successful.

Reference Two[5] presented at the Society of Petroleum Engineers Annual Technical Conference and Exhibition in Anaheim, California, November 2007 explains the resonant vibration theory in more detail as well as its use in extracting long lengths of mud stuck tubulars.

The system is defined as the surface resonant vibrator, pipe string, fish and retaining media.