Experimental Study On Drillability Of High Pressure High Temperature Rock

Study on rock drillability of deep well is the key project to resolve the problem of deep or ultra-deep welldrilling. This study aims at weakness and requirement of rock drillability of deep well test device and experiment research which is in the condition of high pressure and high temperature, respectively in the two aspects of research:Namely the development of high pressure and high temperature rock drillability testing machine and use this finished prototype conduct experimental research on rock drillability.The developing of testing machine, combined with simulation requirements of bottom hole pressure and temperature conditions, finished overall program design of testing machine, also about the test and control systems, pressure and temperature simulation systems, high pressure static and dynamic sealing systems and other systems. Fabricate the experimental aircraft prototype and completed the debugging and trial of the machine, on this basis, make some improvement and optimization.Use the test machine do some rock drillability experiment research. For three different mechanical properties of rock and roller cone, PDC micro drill bit, carried experimental study on influence of confining pressure, pore pressure, and liquid column pressure and temperature to rock drillability. Also the experimental study on impregnated micro drill bit formation pressure sensitive and obtained large number of experimental data. Through the experimental data and experimental phenomena systems analysis, summarized the law of rock drillability under high pressure and temperature conditions.This paper completed the development of a forward-looking high pressure high temperature rock drill testing device, The test system for conducting simulation of deep rock drill test provides an important and effective means to lower the temperature of the environment of formation pressure. Systematically carried out under the condition of high pressure high temperature rock drillability law study, scientific findings reflect the deep rock crushing school characteristics under actual drilling conditions.Thus,high pressure high temperature rock research drillability to improve bit selection and personalized design of science, thus improving deep well, ultra-deep drilling efficiency has great significance.