Theory And Experimental Study Of Hydro-efflux Hammer With Accumulator Used In Oil And Gas Drilling

With the depth of oil and gas well increasing, the difficulty ofhard rock drilling is added too. At present, the traditional rotarydrilling methods with cone bit or PDC bit is more often used. Whendrilling a hard formation, the penetration rate is low, the servicelifetime of bit is short and the cost is high. This paper based on thecenter project of CCSD—researched the Efflux Hammer used indeep drilling .It also based on the project of CCSD—researched theEfflux Hammer cord sampling. Analyses the problem of the effluxhammer, the power can be added by using accumulator throughresearch and experiments.It analyses the rule which the efflux hammer's structureparameter affects the performance. For the first time, it analyses therelation between oil press hammer and efflux hammer. It illuminatesthe feasibility that the accumulator increases the power. Both oilpress hammer and air press hammer obtain 8~10m/s, in velocity, Butthe efflux hammer's velocity is only 2~3 m/s, It has not reached thefastest velocity that the hammer can endure. It is found that air andoil press hammer have accumulator mechanism. It is necessary for oilpress hammer using accumulator, As the flux descends rapidly at theend of the stroke. The back pressure of the piston ascends rapidly,The accumulator accumulates the power temporarily, And it releasesthe power when the system pressure is low. At the same time theaccumulator is one of the most important factors which insure the oilpressure hammer to export high power on the condition of small fluxand high pressure.On the base of theory research and calculate, the paper makes ananalyzing in order to confirm the accumulator' s pressure and cubage.Peng Jian Ming built the dynamical model of the efflux hammer withaccumulator or without accumulator device, and he did experimentswhen the accumulator was in different position(accumulator in frontantrum, in back antrum, in both of the antra). The result indicates thatthe accumulator can make the impact stabilization. And it influencesthe frequency but it has little influence to the power. It is analysedthat efflux hammer work parameter is not suit for the pressure andcubage of the accumulator selected. So it is necessary to analyse andcalculate the pressure and cubage of the accumulator on the basis ofthe theory.The paper builds the dynamical model of the efflux hammer. Itbuilds the piston movement differential equation in strike phase. Andit also builds the piston movement differential equation in backhaulphase, the hammer piston pressure-velocity differential equation, thehammer piston return ball calculation. The paper draws theemulate-real chart of efflux hammer, It builds efflux hammeremulate system model. At the same time, it builds theacceleration calculation and pressure sub-model of front andback cavity, the piston up and down calculation sub-model. thepiston up and down pressed and acceleration calculationsub-model, the piston journey control sub-model. The piston topand impact treatment sub-model. The paper Uses MATLABlanguage and its major tool-Simulink to simulate the elementand hammer`s impacting system. It gets SC-89 hammer'ssimulation data, it draws displacement, velocity, front and backpressure, acceleration curve.The SC-89 hammer was changed in order to researchaccumulator increasing the strike work. The three open pipe wasdevised to fix the accumulator in up antrum. The circuit ofsound and pusle was devised. Base on the LabVIEW dummy flatroof to test the strike work and frequency, and the result iscorrect. The pressure value of up and down antrum wasmeasured. The data was gotten and analysed in several differentcondition. The curve was drawn to show the relation between upand down pressure, frequency, end speed, the accumulatorpressure and cubage.The conclusion is that the efflux hammer work well and thefrequency is steady when the accumulator's pressure and cubageis suitable, and the strike work is added.