Juan reyes-montes

• University of Liverpool

Enhanced Geothermal Systems (EGS) use hydraulic fracturing to create a fracture network that facilitate the circulation of water between injection and extraction boreholes. Microseismic monitoring provides a unique method for the evaluation of the effectiveness and impact of the stimulation and reducing potential risks such as uncontrolled growth...

The purpose of this ISRM Suggested Method is to describe a methodology for in situ acoustic emission monitoring of the rock mass fracturing processes occurring as a result of excavations for tunnels, large caverns in the fields of civil, rock slopes and mining engineering, etc. In this Suggested Method, the equipment that is required for an acousti...

A successful microseismic monitoring project depends on many factors, among which having the optimal monitoring tools and array configuration play a crucial role. A pre-survey array design is an essential step to maximize the output from a monitoring campaign to provide useful feedback for reservoir engineering. This paper proposes the use of the A...

A successful microseismic monitoring project depends on many factors, among which having the optimal monitoring tools and array configuration play a crucial role. A pre-survey array design is an essential step to maximize the output from a monitoring campaign to provide useful feedback for reservoir engineering. This paper proposes the use of the A...

Despite the current easing in demand for increased oil production linked to the global downturn in crude prices, energy demand continuously increases and the long-term demand will require maximizing the productivity of reservoirs and a search into the exploitation of new resources in increasingly challenging environments. In this study, we present...

Ultrasonic velocity surveys in the frequency range of 20 kHz to 120 kHz were carried out in the Excavation Damage Zone (EDZ) of the ONK-TKU-3620 niche, excavated through drill and blast, to obtain a P-wave tomographic image of the top 0.8 m of the tunnel floor as part of the geophysical characterisation of the EDZ. The P-wave tomography covered a t...

Microseismic monitoring, the engineering application of earthquake seismology, provides an insight into the location and extent of fracturing induced by the caving process. The spatial characteristics of the observed microseismicity provide valuable validation for the back analysis of the cave process through numerical models (e.g. Pierce et al. 20...

Continuous acoustic emission (AE) data recorded during rock deformation tests facilitates the monitoring of fracture initiation and propagation due to applied stress changes. Changes in the frequency and energy content of AE waveforms have been previously observed and were associated with microcrack coalescence and the induction or mobilisation of...

The fast sweeping method has been proved very efficient in calculating the first arrivals in isotropic media. In this study, we extend the fast sweeping method to heterogeneous anisotropic medium by adapting the Lax-Friedrichs local scheme. The new fast sweeping method is able to solve the first arrival traveltime field for both qP and qS waves. By...

Passive monitoring of induced microseismic (MS) events provides a unique means for imaging fracture propagation in response to engineering operations. Particularly during hydraulic treatment of hydrocarbon-bearing reservoirs rock MS monitoring provides feedback to field operators on the effect of the treatment and the changes imposed on the fractur...

seismic (MS) events from streaming data recorded by surface monitoring survey. The symmetric nature of the semblance with respect to the origin time was used to identify the MS location. In this paper, we form a comprehensive workflow by extending this algorithm to include arrival time refinement using cross-correlation and nonlinear optimization s...

Microseismic (MS) monitoring is extensively applied as a method for remotely imaging the effect of the treatment and the changes imposed on engineered reservoirs both in real time or post-treatment analysis. 3D microseismic locations could provide us the first-hand information of the geometry and extent of induced fracture network, but there are st...

Microseismic monitoring of hydrofracture treatments can result in a significant number of events displaying a high energy S-wave arrival but have a P-wave that is close to or below the ambient noise level. Traditional location methods, relying on P-wave polarization information to determine the source vector, would fail to determine a source locati...

Hydraulic fracturing stimulates reservoir and imposes stress changes in the surrounding rock that typically induce or trigger seismicity with a wide range of magnitudes. Seismic monitoring provides insight into the reservoir deformation and give critical feedback to the on-going stimulations. We have developed a passive seismic tomography technique...

The coalescence of microcracks into major fractures marks the onset of major damage in rock and induces significant changes in its geotechnical and sealing properties. The interaction between neighbouring fractures affects the deformation process leading to this major failure. This study presents the analysis of load-induced fracture using spatial...

A comparative analysis of continuous acoustic emission (AE) data acquired during a triaxial compression test, using a 12-bit and a 16-bit acquisition system, is presented. A cylindrical sample (diameter 50.1 mm and length 125 mm) of Berea sandstone was triaxally deformed at a confining pressure of 15 MPa and a strain rate of 1.6E-06 s-1. The sample...

The accuracy in the location of microseismic (MS) events relies, among other factors, on the use of a realistic velocity model in the forward calculation of travel times. During the hydraulic stimulation of deep rock reservoirs, the physical properties of the rock are altered and therefore the velocity structure is subject to changes along the trea...

The Fast Sweeping Method (FSM) is a finite difference algorithm providing significant computational efficiency and modelling capability in calculating the first arrivals of seismic P- or S-waves. Based on the calculated travel-timetable, we stack waveform amplitude for every possible source location and origin time followed by semblance weighting....

An analysis of continuous acoustic emission waveforms from a triaxial rock fracture experiment is presented in this paper. A cylindrical sample of Westerly granite was heated to a temperature of 850°C before being triaxially deformed in a geophysical imaging cell. The sample was loaded hydrostatically to 25 MPa and then differentially until failure...

Observations from field monitoring indicate the presence of existing fracture networks significantly affect, and may control, the history of hydraulic treatments. Existing fractures allow pathways for treatment fluids to migrate efficiently through the formation, stimulating connectivity to larger reservoir volumes. This paper examines the relation...

Microseismic monitoring, the engineering application of earthquake seismology, provides an insight into the location and extent of fracturing induced by the caving process. The spatial characteristics of the observed microseismicity provide valuable validation for the back analysis of the cave process through numerical models (e.g. Pierce et al. 20...

Fracture Network Engineering (FNE) is the engineering design of rock mass disturbance through the use of advanced techniques to model fractured rock masses numerically, and then correlate field observations with simulated fractures generated within the models. Microseismic (MS) monitoring is a standard tool for evaluating the geometry and evolution...

Hydraulic fracturing methods for reservoir treatment are applied to increasingly complex environments including naturally or previously fractured reservoirs. The potential interaction with the in-situ fracture network or with fracturing induced in previous treatments plays a crucial role in the outcome of the stimulation, controlling the extent and...

Fracture network engineering (FNE) involves the design, analysis, modeling, and monitoring of infield activities aimed at enhancing or minimizing rock mass disturbance. FNE relies specifically on advanced techniques to model fractured rock masses and correlate microseismic (MS) field observations with simulated microseismicity generated from these...

In order to assess the feasibility and performance of geological sequestration as a long-term solution for CO2 depletion, it is crucial to evaluate and monitor the integrity and stability of the caprock. Direct comparison with results from field observation and modeled microseismicity provides a unique tool to evaluate the evolution of the treated...

This paper describes synthetic rock mass (SRM) modeling, a new approach for simulating the mechanical behavior of jointed rock mass. This technique uses the bonded particle model for rock to represent intact material and the smooth-joint contact model (SJM) to represent the in situ joint network. The macroscopic behavior of an SRM sample depends on...

In this paper, in order to develop robust predictive models for engineering the reservoir and the induced or mobilized fracture network, a fully dynamic 2D Synthetic Rock Mass model is validated to simulate fluid injection in a geothermal reservoir by comparing modeling geometries of hydraulic fractures and induced seismicity with actual results. T...

Transgranular microcracking is fundamental for the initiation and propagation of all fractures in rocks. The geometry of these microcracks is primarily controlled by the interaction of the imposed stress field with the mineral elastic properties. However, the effects of anisotropic elastic properties of minerals on brittle fracture are not well und...

The transition from surface to underground mining presents a series of technical and operational challenges, in particular those arising from the interaction between the cave and the overlying pit. Seismic monitoring provides a unique means to obtain near real-time information about the development of the fracturing process induced by the mining op...

Hydrofracture stimulations are widely used to optimize production volumes and extraction rates in petroleum reservoirs, enhanced geothermal systems and preconditioning operations in caving mines. Microseismic monitoring is now becoming a standard tool for evaluating the geometry and evolution of the fracture network induced during a given treatment...

Inducing fractures in rock masses is current practice for the exploitation of deep ore bodies and the optimization of production in petroleum reservoirs and enhanced geothermal systems. The combination of microseismic field observations with numerical tests provides a tool to enhance the knowledge of the mechanics of the induced fracturing. The enh...

Microseismic monitoring is routinely used for imaging the fracture network induced by hydrofracture treatments. One of the principal sources of uncertainties in the location of hypocentres is the velocity structure used in the location algorithm, which in most cases is approximated by layered models from sonic logs or estimated from perforation sho...

The cluster index provides a means to identify the seismic activity corresponding to the development of connected fracturing that creates paths for fluid transmission during hydraulic stimulations. The location of induced microseismic events is combined with their source dimension, interpreted from the frequency content, to interpret the degree of...

Acoustic emission (AE) monitoring is a non-invasive method of monitoring fracturing both in situ, and in experimental rock deformation studies. Until recently, the major impediment for imaging brittle failure within a rock mass is the accuracy at which the hypocenters may be located. However, recent advances in the location of regional scale earthq...

Microseismicity has been extensively used to monitor rock mass response to stress changes; in particular excavation induced damage at underground mines and engineered structures. A methodology has been developed to extract information on fracturing mode and orientation from existing microseismic catalogues. The method is based on the statistical an...

Microseismicity is extensively used to monitor induced damage accumulation and stability of underground structures. Classical location routines in this context can often not resolve the potential coalescence of the induced microcracks, since the location accuracy is on the order of magnitude of the largest fractures observed. Most of the uncertaint...

Methods based on acoustic emission and microseismicity (AE/MS) have proven to be valuable for monitoring microcracking at the Underground Research Laboratory (URL) in Canada. The source locations of the seismic events induced by the excavation have helped to map out the extent of the excavation damage/disturbed zone (EDZ) around tunnels. This paper...

Microseismicity has been extensively used to non-destructively monitor induced damage accumulation and stability of underground structures. Source location is one of the most fundamental characteristics of seismicity in order to provide this information. However there is an uncertainty in its determination, arising from a combination of three facto...

The interaction and coalescence of stress induced microcracks mark the onset of significant damage in a rock mass. Fracture initiation and propagation have been extensively studied both theoretically and through laboratory rock deformation testing. These studies have determined the critical conditions for crack interaction, which has lead to the de...