Analysis Of The Temperature On The Mechanical Properties Of Granite Experimental Study On Effect And The Hole Wall Stability

With the progress of science and technology, the drilling technology becomesmore and more sophisticated. In the deep strata, the environment is high temperatureand high pressure. At the same time, the physical and mechanical properties of deepstrata will change, the wellbore stability is very important.In the deep drilling, the deep granite formation will be impact by the temperature.In this paper, the granite sample are taken to heat and cold, and measure P-wavevelocity, then using the indirect test method of the microscopic theory to know thechange of internal structure of granite and the impact of micro-crack propagation.Secondly, the heating and cooling of the granite specimens are taken to make theuniaxial and the triaxial tests. From the tests, the impact of temperature on themechanical properties of granite can been knew, and the temperature change inrelationship between the corresponding parameters will been getting. Then, we canuse the experiment reports to choose the parameters of numerical simulate. Finally,based on the previous pilot study and the relevant law, the circulation process ofdrilling fluid in the actual drilling will been simulated by ansys numerical software.Through the use of ultrasound method, the wave velocity of the heating andcooling samples vary greatly, so we can believe that there are great relationship withthe micro-crack extending, linking and temperature. Simultaneously, the internalstructure of rock has been changed. Second, according to the reports of tests, themechanical properties of granite are effect by the temperature, such as elastic modulus,peak stress, internal friction, cohesive force, and so on. Third, not only the originalstrata of ground stresses be considered, but also the fluid column pressure of thedrilling fluid taken into account. At the same time, the effect of temperature betweenthe drilling fluid that in the ring of air circulation and the borehole and its surroundingrock should been taken into considered. Because, the change of temperature will madethe mechanical properties of the borehole and its surrounding rock will be changed,and the wellbore been unstable.