The Service Life Of Extension Drilling Tools

• Posted by drilling kaiqiu May 26, 2021 - Filed in Business - #Reaming Bit  #Extension Drilling Tools  - 222 views

         Reaming Bit is a positive displacement downhole power drilling tool that uses drilling fluid as power and converts fluid pressure energy into mechanical energy. When the mud pumped by the mud pump enters the motor through the bypass valve, a certain pressure difference is formed at the inlet and outlet of the motor, which pushes the rotor to rotate around the axis of the stator, and transmits the speed and torque to the drill bit through the cardan shaft and the drive shaft. , So as to achieve drilling operations.

        Introduction

         A progressive cavity type volumetric hole bottom power machine, referred to as screw drilling tool. The screw drilling tool, which uses mud and clean water as the power medium and is transported to the bottom of the hole through the center hole of the drill pipe, is essentially an energy conversion device that converts liquid pressure energy into mechanical energy. When drilling, the screw drilling tool directly drives the core tube and the drill bit connected to the drive shaft at the bottom of the hole to rotate. The entire drill string is only used as a channel for conveying high-pressure working medium and a rod supporting the counter torque of the drill bit, and does not rotate. Compared with conventional drilling, the use of screw drilling tools has many advantages, such as drastically reduced drill pipe wear and high drilling speed. It is the main tool for drilling directional holes and has played a role in the field of drilling.

   

        In 1955, the United States Christensen Mine Drilling Products Company began research based on the Moinuo principle, and it was the first to succeed in 1964, named "Dana Drill"; the Soviet Union successfully researched the "convex" screw drilling tool in the early 1970s; China The Exploration Technology Research Institute of the Ministry of Geology and Mineral Resources successfully developed screw drilling tools in the early 1980s. So far, the United States, Russia, China and Germany have produced screw drilling tools.

   

         Screw drilling tools were first used to drill vertical holes, mainly used to drill various directional holes and special engineering holes (such as mine freezing holes). The greater drilling depth is 9023 meters. At present, the smallest diameter of screw drills in the world is 44.5 mm, and the larger diameter is 304.8 mm. When using screw drilling tools for core drilling, a core tube should be added between the drive shaft and the bit to take the core.

   

         The screw drilling tool is composed of bypass valve, screw motor (rotor and stator), universal joint, bearing and drive shaft. Its core is screw motor. In the screw motor rotor and stator transmission pair, the number of stator teeth Z1 is one more than the number of rotor teeth Z2: that is, Z1=Z2+1. Their gear ratios are usually called transmission ratios, which can be selected arbitrarily (1:2, 2:3,..., 9:10) during design. High-speed screw drilling tools should be designed with a small gear ratio screw motor, and low-speed and high-torque screw drilling tools should be designed with a large gear ratio screw motor. With the increase of the rotor-to-stator gear ratio, its efficiency gradually tends to decrease; the output torque of the screw drill depends on the working pressure drop through the motor, and the output speed depends on the flow of the working medium through the screw motor.

   

         When drilling, conventional drilling equipment such as drilling rigs, mud pumps, drill pipes and rigs are still needed. When constructing directional drilling, it is necessary to use an orienting instrument to orient the tilting tool. The tilting tools used with screw drills include bent joints, bent outer pipes and eccentric blocks. The use of screw drilling tools to construct directional holes can improve drilling quality, provide geological data, save footage, reduce costs, and solve many engineering problems that cannot be constructed. Therefore, it is a special tool for drilling engineering.

   

         The service life of Extension Drilling Tools is generally 150 to 200 hours. The weak link is that the stator rubber has low high temperature resistance and the bearings are easily damaged. Accelerate the research and development of wear-resistant and high-temperature resistant elastic materials and reliable bearing systems for the manufacture of stators, so that the working life of screw drills has been significantly improved. And developed a low-speed high-torque screw to be suitable for drilling deep holes and ultra-deep holes.