Experimental Study On Shale Micro-indentation

Shale gas wells in the drilling process and conventional rock mechanics parameters by macro rock mechanics experiment,the down-hole coring,logging and other means to obtain,but coring difficulties,especially shale core and a waste of the effective production time,increase the cost of drilling,so forcing us to explore a low cost,sample preparation is simple,under certain conditions,rock mechanical parameters measured can replace the macro mechanical parameters of rock method.Therefore,this paper presents a new method of mechanical properties of rock are determined based on the micro indentation experiments.The main research contents of this paper include:choosing test method;determine the experimental equipment,the experimental sample acquisition and preparation,determination of the loading force and loading rate;Study on the influencing factors of micro indentation experiments,study on the relation of different hardness;through fine shale-mechanical characteristics of macro scale contrast analysis prove the feasibility of the experimental study;through the micro indentation experiments of Wu feng and Long maxi shale mechanical properties and in the same layer at different indentation direction comparison of mechanical properties.This study came to the following conclusion:1)Shale micro indentation test for determining the load of 50N;loading rate for 10N/min.2)Micro indentation test to quickly determine the indentation of shale modulus indentation hardness and mechanical properties of these two important parameters,by comparison with uniaxial and Triaxle mechanical experiment,can be used to replace conventional mechanical experiments.3)Relationship between hardness of different layers of shale varies.Head due to Boltzmann,Vickers hardness value for indentation hardness 0.0918 times,MA hardness indentation hardness of about 0.9671 times.4)Through studying the seven factors of Indenter tip radius and surface roughness effects on the experimental results is very large.5)Indentation modulus in Wu feng formation shale 17GPa,indentation hardness 1GPa.Parallel bedding surface indentation modulus when the pressure is greater than the vertical stratification interface when indentation modulus(2.2GPa).6)Shale brittleness index between 0.19 to 0.64,the average value of 0.38.The thesis research can form shale a measurement of mechanical properties of micro-indentation techniques,using a mesa-scale experimental method to alternative macro-scale rock mechanics experiment on mechanical parameters of drilling in shale gets very helpful.