In February 2009, Varel Company of the United States first introduced A-Force series air drilling roller bit with sealed sliding bearing, which was specially used for underbalanced drilling, including air drilling, foam drilling and atomization drilling. This kind of drilling rig adopts a patented technology of our company, which prolongs the sealing life by reducing the temperature inside the seal, and adopts a conical sealing circular plate to resist the fluctuation of bottom hole pressure and ensure a good sealing interface, which plays an important role in ensuring the normal operation of the bearing under huge internal pressure.
Recently, the following improvements have been made: the new lubricating device effectively reduces the working temperature of the bit system, prevents the internal bearing from heating, and keeps continuous cooling; More wear-resistant cemented carbide inlay technology prevents the surface of the journal from being worn, thus prolonging the life of the whole bearing; The bit structure is redesigned to reduce the length of the bit itself, thus increasing the controllability.
All A-Force series rigs are equipped with improved sealed sliding bearing system, which is specially designed with new technology to improve the heat resistance of bearings under heavy drilling conditions. The cutting teeth of the drill bit are all treated by HET patented technology, and its cutting structure and tungsten carbide brand are specially equipped for underbalanced drilling.
A heat insulation plate is designed between the drill bit seal and the inner bearing to protect the seal from overheating, reduce the working temperature of the seal system and prolong the seal life. The drill bit is also equipped with a conical washer, which can make the sealing system better adapt to pressure fluctuation while still maintaining a good sealing position and interface. This effect is very important for the large internal bearing pressure that may be encountered in air, foam and atomization drilling. In addition, the bearing rigidity of A-force series bit is better and the tolerance is smaller, so the bit can bear more WOB.
The material improvement of this product includes adopting a new grease formula with better high temperature stability and welding hard metal with better wear resistance on the surface of drill bearing. At the same time, the bit leg forgings have been redesigned to make them stronger and more stable, and the overall bit length has been reduced.
Second, the scope of application and application examples
As for PDC bit, Varel company is constantly exploring new ways to meet users' directional needs. Based on the closed-loop system of the combination of geoscience and SPOT proprietary software program, the company has established a platform for the redesign of its Navigator series PDC bits, which enables designers to build models of bit specifications and cutting structures, optimize bit components according to specific requirements, and predict which structure can lead to the required product performance.
During the drilling of shale interval, a large drilling operator asked Varel Company to provide a more stable drill bit. The company recommended a VM6 1 9H Navigator PDC bit with seven 7/8-inch six blades, which drilled 453 1ft in 45.25 hours, reaching a total depth of 9885ft, and its ROP was as high as 65438.
Three. sources of information
Huang, Xue Qilong.20 20 10/0. New progress of foreign bit technology. Petroleum machinery (4)