20. “Bitków” type drilling rig

“Bitków” type drilling rig was used for percussion drilling of boreholes to a depth of approximately 1 500 m. It was built in 1923 on the oil field of Bitków. The “Bitków” drilling system, implemented by Polish constructors, was used in two versions: with a rocking beam or a jerk-line. The principle of jerkline drilling was as follows: the drilling set (drilling bit – weight – jars) was attached to a drill rope. After running the bit to the well bottom, the line was pulled through a roll fixed on the crank of an attachment shaft. The attachment rotary movement with the crank attached caused regular lifting and free dropping of the drilling set which resulted in rhythmical impacts of the drilling bit onto the well bottom. Hence, the colloquial name of the process was “jerk-line method”. The rotation of the drill bit around its axis to drill the hole centrally was achieved by a device called a rope socket. During the drilling progress the line was released gradually in order to cause the drilling bit impact by the line elasticity. This resulted in more effectiveness of drilling but required great talent and skills of drillers.