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Causes and dangers of low pressure brittle fracture of geological drill pipe!
Release time:
2019-06-12
Author:
Source:
Causes and dangers of low pressure brittle fracture of geological drill pipe! A drill pipe is a steel pipe with a thread at the tail, which is used to connect the surface equipment of the drilling rig and the drilling and grinding equipment or bottom hole device at the bottom of the drilling. The purpose of the drill pipe is to carry drilling mud to the drill bit and raise, lower or rotate the bottom hole device together with the drill bit. The drill pipe must be able to withstand huge internal and external pressure, distortion, bending and vibration. Geological drill pipe geological drill pipe low pressure brittle fracture causes and dangers! Low stress brittle fracture of geological drill pipe accounts for a large proportion of the whole drill string failure, and its risk is also very high. Low stress brittle fracture occurs in both drill pipe and drill string conversion joints. Such
Causes and dangers of low pressure brittle fracture of geological drill pipe!
A drill pipe is a steel pipe with a thread at the tail, which is used to connect the surface equipment of the drilling rig and the drilling and grinding equipment or bottom hole device at the bottom of the drilling. The purpose of the drill pipe is to carry drilling mud to the drill bit and raise, lower or rotate the bottom hole device together with the drill bit. The drill pipe must be able to withstand huge internal and external pressure, distortion, bending and vibration.geological drill pipe
Causes and dangers of low pressure brittle fracture of geological drill pipe!
Low stress brittle fracture of geological drill pipe accounts for a large proportion of the whole drill string failure, and its risk is also very high. Low stress brittle fracture occurs in both drill pipe and drill string adapter.. For example, the brittle fracture of the drill pipe weld and the brittle fracture of the drill stand and the thread of the drill string conversion joint are caused by fatigue damage, and their remarkable characteristics are that there is no macroscopic precursor before the sudden fracture, which cannot be found by general lateral measurement means, thus causing catastrophic accidents unconsciously..Therefore, low stress brittle fracture is one of the most dangerous fracture methods.
geological drill pipe
Performance form of corrosion and wear of drill pipe
Corrosion wear is a phenomenon of material loss caused by the chemical or electrochemical reaction between the surface material and the surrounding medium during the relative sliding process of the friction pair surface. When the drilling fluidCO2 andH2SWhen the content is high, it will
drilling fluidpH decreases,H ion directly with the iron rod columnFeExchange of electrons, thereby dissolving the drill pipe; during drilling,Oxygen in the atmosphere and oxygen in the surface and groundwater will be mixed into the drilling fluid through mud pumps and other equipment during the circulation process.
Free oxygen, increased oxygen contentCorrosion of iron in drill pipe,Corrosion products are black and denseFe3O4and red crispFe2O3compounds, mainly from drilling fluid treatment agents, mainly from formation water and other corrosive media includingCl-,SO42-,Ca2 ,CO32-,HCO3-Wait,Among themCl-significant impact,Small radius, strong penetrating ability,Easily through the very small pores in the surface membrane of the drill string member,Direct contact with metal,Play the role of catalysis and corrosion promotion. The phenomenon of fatigue fracture of surface materials to form pitting or spalling.
geological drill pipe
Poor drilling technology will cause the drill pipe to break.
(1) Reasonable bit and drilling tool gradation, maintain a reasonable outer ring gap, use appropriate drag reduction agents, maintain the lubricity of the mud, and reduce the rotation resistance of the drilling tool.
(2) Prevent the drill pipe from breaking due to over-diameter drilling and bending of the drill tool.
(3) Reasonable drilling process parameters, too high bit pressure and too high speed will easily cause the drill pipe to break.
(4) In the case of complex stratum, the rope core drilling shall be adopted, and the corresponding treatment measures shall be adopted, otherwise the drill pipe breaking accident will occur continuously.
(5) Avoid strong upsetting and twisting during operation.
Key words:
Drill Pipe, Geological Drill Pipe, Spiral Drill Pipe
