Experimental research on the quasi three-axis hydraulic fracturing of coal
Abstract：In order to study the hydraulic fracturing of coal mechanism thoroughly,a modification of MTS815.02 electro-hydraulic servo rock mechanical testing system was carried firstly.Analogous materials consisting of powder coal,cement and gypsum with different material proportions were used.The quasi tree-axis hydraulic fracturing tests were carried out on the coal specimens and the raw coal specimens.The comparison of the test results with the scene compression fracture date was also conducted.The result indicate that reasonable material proportions can be described as∶Coal∶Cement∶Gypsum =1.5∶1∶1.The crack always propagates along the in-situ stress＇s biggest direction and the character of crack surface has the important influence on the fracturing fluid flowing in the seam.It also indicate that bigger pump jet quantity leads to bigger breakdown pressure.
Keywords：hydraulic fracturinganalogous materialin-situ stressbreakdown pressurepreexisting fissures
Publication Date：2011-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)