Corrosion Law Of Gas Drilling And Failure Analysis Of Drilling Tools

Gas drilling develop rapidly over the years because of a lot of advantages,at the same time,it also has some problems during application in the drilling.During the gas drilling,drill tools are always suffered from the erosion of the formation fluid.Thedownhole fluid frequently contained gas(air、CO2、H2S,etc)、liquid(formation water)、solid (drilling cuttings),it has stong corrosivity.In order to inprove economic efficiency,reduce the drilling cost,we must intensive study the influencing factors and mechanism of corruptionerosion.The main research contents of this paper are as follow:(1)Under the help of high temperature high pressure reactor to simulate the corrosion environment in gas drilling.Through coupon weight loss to study corrosion behavior during air drilling、air foam drilling.Using scanning electron microscope、X-ray diffraction、power spectrum analysis the corrosion mechanism of diesel engine tail gas drilling、air drilling、air foam drilling.(2)Not only analysising the erosion theory but also using fluid mechanics software to simulate the drill pipe、drill pipe and clearance pipeline were erosioned by cuttings.The result of study indicate that:the change of the flow field is not the main factors of the leak of drill pipe ontology in the drill pipe sub of no acanthopore,the change of the flow field become one of the main factors only when the drill pipe have corrosion pits.The position of the biggest erosion rate was in the mother joint slope during gas drilling. The erosion rate increases with the corners of the pipe.(3)Typical CO2corrosion prediction models are summarized in the oil/gas field development.Home-made corrosion monitor are used to monitor corrosion tests in the M well.Morphology and composition of the corrosion products are analyzed. Compared with the corrosion rate of CO2corrosion prediction models,the calculation of the actual corrosion rate are higher than the forecast.(4)Using scanning electron microscope、X-ray diffraction、power spectrum analysis the corrosion fatigue failure of drilling tools in gas drilling and combined with corrosion behavior and corrosion mechanism research to put forwardpreventive measures of corrosion.Providing basis for scientific antisepsis.