... the fracturing processes. At present, the number of AE events and the spatial distribution of AE locations are the two main factors considered in the evaluation of fracturing effect. A large number of AE events and a wide spatial distribution of AE locations often indicate a better fracturing effect. However...

... of deformation in the relaxation stages. As the strain level for relaxation increased, the stress dropped and correspondingly the number of AE events increased. The temporal analysis of the different cracking processes detected through AE and DIC revealed the higher contribution of tensile cracks in relaxation...

..., controlled pore pressure, and acoustic emission (AE) measurements. These studies provide valuable insights into the seismic and aseismic behavior of fault gouge coupled with fluid. friction ae event fluid-saturated gouge geophysical research upstream oil & gas fluid injection seismicity...

... and shows potential to make field completions more efficient. flow in porous media injection pressure reliably hydraulic fracturing stephansson ae event reservoir geomechanics fluid dynamics pre-breakdown event primary fracture experiment reservoir characterization upstream oil & gas...

... developed. By evaluating the time-variation of the source mechanisms of the AE events produced, it was noted that the number of AE events were spread-out throughout the specimen rather than concentrated near the flaws. This is interpreted to be a result of pore pressures diffusing through a larger area...

... of the Montney shale lithology compared to more brittle granitic specimens used in many previous studies, and the reverberatory character of the recorded waveforms, AE seismicity was relatively sparse (600 events) and only a small fraction (about 6%) of AE events could be located. Nevertheless, the hydraulic...

... more than that for the specimens at room temperature. geothermal reservoir hdr specimen Loading Rate hydraulic fracturing heat-treated hdr specimen ae number AE event frequency fracture toughness Wang Upstream Oil & Gas SCB specimen fracture mechanics characteristic room...

... Upstream Oil & Gas in-situ ae AE event borehole plane in-situ acoustic emission frequency range sensor kHz nakatani cementation experiment naoi plenker excavation AE sensor 1. INTRODUCTION For the safe use of underground structures like mines monitoring of their conditions...

... and propagation of hydraulically-induced fractures under uniaxial and biaxial loading conditions, a very limited number of experimental studies investigate the effect of triaxial loading conditions on fracture initiation and propagation. hydraulic fracturing prefabricated flaw AE event fluid pressure...

... process of hydraulic fracturing using acoustic emission (AE). Experimental results show that the location of small few AE events along BP near the wellbore and stable injection pressure indicated the fracturing fluid leaking into the dilated BP under low injection rate (= 10 mL/min). In this case the SRV...

... on a set of 6 transducers throughout a laboratory hydraulic fracturing experiment. The number of waves, and subsequently the number of located AE events, make structures determined within dense point clouds of AE data difficult to interpret. Previous work in this area used several methodologies...

... of a MST test. Measurements were made on a weakly consolidated Miocene sandstone. Less than 2% of total number of AE events were recorded up to the MSM suggesting that minimal plastic strain has occurred, and the yield surface has not been approached. In contrast, for the MCS, 80% of AE events are observed...

... into a triaxial geophysical imaging cell under a confining pressure of 10 MPa. The macroscopic shear slippage generated numerous AE events, which were processed and studied for fracture propagation. Detailed analysis based on AEs and ultrasonic velocity surveys include deformation-induced velocity anisotropy...

... of the effective pressure law to borehole deformation. Located AE events coincide with post-test observations of damage and fracture locations. Comparison of AE behavior between the experiments with pore pressure show that breakouts develop prior to peak stress, and continued loading drives damage further...

... ABSTRACT: Here, a shear-tensile crack (STC) model is presented as suitable for Acoustic Emission (AE) events and compared to a traditional MT (Moment Tensor) approach. Experimental data was obtained from a uniaxial compression test performed on a Westerly Granite (WG) specimen using a 14...

... ABSTRACT: Temporal and spatial acoustic emission (AE) event analysis, 3D fracture networks construction obtained from X-Ray CT images and thin section studies of the five tested specimens on isotropic pegmatite (PGR) and anisotropic migmatitic gneiss (VGN) samples obtained from ONKALO nuclear...

... and could be detected around weak BPs far away from the wellbore before HF initiation. When the fracturing fluid slowly leaked into the BPs, the injection pressure remained stable and AE activity became low. Only a few AE events with low amplitude were located along the BP near the wellbore. Numerous shear...

... recorded. Approximately 50% and 25% of these events were locatable using at least 8 and 10 consistent P- and S-wave onsets, respectively. A cluster analysis found a big planar cluster with 142 AE events. We studied source mechanism and moment tensors of these clustered AE events using clear discernible...

...-block system separated by a discontinuity as an analogue to a large natural fault. The induced hydraulic fracture was monitored with acoustic emissions (AE) throughout initiation, propagation, and interaction with the large fault. Individual AE event source characterization was performed to obtain mode...

... Upstream Oil & Gas AE event sequence spectral content geophysical research acoustic emission Earthquake Marone simulated fault gouge frequency stick-slip cycle stick-slip event waveform laboratory stick-slip event 1. INTRODUCTION Tectonic faults exhibit a wide variety of failure modes...