To all geomechanics expert, My name is Prapun Sooksawat, I am an reservoir engineer working in a new geomechanics team in Thailand national oil and gas company. I have got the Triaxial compression tests results from an unknown laboratory. In this work, for each depth, a triplet of plugs was taken each of which tested at different confinement( 5 Mpa, 10 Mpa, 20 Mpa) in order to establish the failure envelope. According to the axial stress/strain plot, I wonder why all tests were performed with unloading axial stress at early period? I normally found this procedure only in a multi stage triaxial test (MST) when number of core is limited but still require multiple ...