Normal faulting activated by hydraulic fracturing: A case study from the Barnett Shale, Fort Worth Basin

Surface microseismic arrays enable long-term field-scale monitoring over multiple stimulations during the life of an unconventional field. In this study, we show highly economic methods of monitoring with sparse surface arrays in the Barnett Shale and develop an alternatative method of processing to enable good vertical and horizontal resolution of located events. We show that sparse surface monitoring arrays enable not only the detection and location of high numbers of microseismic events but also source mechanism characterization. This case study illustrates how hydraulic fracturing activated normal faulting at a distance of approximately 1 mile from stimulated wells. We show that the source mechanism enables us to resolve between newly created hydraulic fractures and activated faults. The differences in source mechanisms and b-values of newly created fractures and activated faults are consistent with independently processed temporary star-like arrays, which are also deployed over the same stimulation.

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Errata

The Leading Edge ◽

10.1190/tle39040291b.1 ◽

2020 ◽

Vol 39 (4) ◽

pp. 291-291

Keyword(s):

Hydraulic Fracturing ◽

Barnett Shale ◽

Fort Worth ◽

Normal Faulting ◽

Fort Worth Basin ◽

The Third ◽

Mail Address ◽

E Mail

The March 2020 TLE article by Alexandrov et al., “Normal faulting activated by hydraulic fracturing: A case study from the Barnett Shale, Fort Worth Basin,” contained an error in the third author's affiliation and e-mail address. Umair bin Waheed's correct affiliation is King Fahd University of Petroleum and Minerals, and the correct e-mail address for the author is [email protected] .

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Distance Metric Based Multi-Attribute Seismic Facies Classification to Identify Sweet Spots within the Barnett shale: A Case Study from the Fort Worth Basin, TX

10.1190/urtec2013-034 ◽

2013 ◽

Cited By ~ 1

Author(s):

Atish Roy ◽

Vikram Jayaram ◽

Kurt Marfurt

Keyword(s):

Seismic Facies ◽

Barnett Shale ◽

Fort Worth ◽

Distance Metric ◽

Fort Worth Basin ◽

Facies Classification ◽

Sweet Spots

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Natural sealed fractures in mudrocks: A case study tied to burial history from the Barnett Shale, Fort Worth Basin, Texas, USA

Marine and Petroleum Geology ◽

10.1016/j.marpetgeo.2013.12.006 ◽

2014 ◽

Vol 55 ◽

pp. 122-141 ◽

Cited By ~ 30

Author(s):

Marta Gasparrini ◽

William Sassi ◽

Julia F.W. Gale

Keyword(s):

Barnett Shale ◽

Fort Worth ◽

Burial History ◽

Fort Worth Basin

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A Novel Coupled Approach to Investigate the Spatiotemporal Evolution of Fracturing-Induced Seismicity: Case Study

10.2118/204156-ms ◽

2021 ◽

Author(s):

Gang Hui ◽

Shengnan Chen ◽

Fei Gu

Keyword(s):

Hydraulic Fracturing ◽

Induced Seismicity ◽

Spatiotemporal Pattern ◽

Hydraulic Fractures ◽

Spatiotemporal Evolution ◽

Coupled Flow ◽

Seismicity Rate ◽

Failure State ◽

Pkn Model

Abstract The recent seismicity rate increase in Fox Creek is believed to be linked to the hydraulic fracturing operations near the region. However, the spatiotemporal evolution of hydraulic fracturing-induced seismicity is not well understood. Here, a coupled approach of geology, geomechanics, and hydrology is proposed to characterize the spatiotemporal evolution of hydraulic fracturing-induced seismicity. The seismogenic faults in the vicinity of stimulated wells are derived from the focal mechanisms of mainshock event and lineament features of induced events. In addition, the propagation of hydraulic fractures is simulated by using the PKN model, in combination with inferred fault, to characterize the possible well-fault hydrological communication. The original stress state of inferred fault is determined based on the geomechanics analysis. Based on the poroelasticity theory, the coupled flow-geomechanics simulation is finally conducted to quantitatively understand the fluid diffusion and poroelastic stress perturbation in response to hydraulic fracturing. A case study of a moment-magnitude-3.4 earthquake near Fox Creek is utilized to demonstrate the applicability of the coupled approach. It is shown that hydraulic fractures propagated along NE45° and connected with one North-south trending fault, causing the activation of fault and triggered the large magnitude event during fracturing operations. The barrier property of inferred fault under the strike-slip faulting regime constrains the nucleation position of induced seismicity within the injection layer. The combined changes of pore pressure and poroelastic stress caused the inferred fault to move towards the failure state and triggered the earthquake swarms. The associated spatiotemporal changes of Coulomb Failure Stress along the fault plane is well in line with the spatiotemporal pattern of induced seismicity in the studied case. Risks of seismic hazards could be reduced by decreasing fracturing job size during fracturing stimulations.

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Full-waveform based microseismic source mechanism studies in the Barnett Shale: Linking microseismicity to reservoir geomechanics

Geophysics ◽

10.1190/geo2013-0094.1 ◽

2014 ◽

Vol 79 (2) ◽

pp. KS13-KS30 ◽

Cited By ~ 21

Author(s):

Fuxian Song ◽

Norm R. Warpinski ◽

M. Nafi Toksöz

Keyword(s):

Seismic Moment ◽

Source Mechanism ◽

Fracture Plane ◽

Barnett Shale ◽

Natural Fractures ◽

Data Set ◽

Full Waveform ◽

Geomechanical Analysis ◽

Source Mechanisms ◽

Well Data

Seismic moment tensors (MTs) of microearthquakes contain important information on the reservoir and fracturing mechanisms. Difficulties arise when attempting to retrieve complete MT with conventional amplitude inversion methods if only one well is available. With the full-waveform approach, near-field information and nondirect waves (i.e., refracted/reflected waves) help stabilize the inversion and retrieve complete MT from the single-well data set. However, for events which are at far field from the monitoring well, a multiple-well data set is required. In this study, we perform the inversion with a dual-array data set from a hydrofracture stimulation in the Barnett Shale. Determining source mechanisms from the inverted MTs requires the use of a source model, which in this case is the tensile earthquake model. The source information derived includes the fault plane solution, slip direction, VP/VS ratio in the focal area and seismic moment. The primary challenge of extracting source parameters from MT is to distinguish the fracture plane from auxiliary plane. We analyze the microseismicity using geomechanical analysis to determine the fracture plane. Furthermore, we investigate the significance of non-DC components by F-test. We also study the influence of velocity model errors, event mislocations, and data noise using synthetic data. The results of source mechanism analysis are presented for the events with good signal-to-noise ratios and low condition numbers. Some events have fracture planes with similar orientations to natural fractures delineated by core analysis, suggesting reactivation of natural fractures. Other events occur as predominantly tensile events along the unperturbed maximum horizontal principal stress direction, indicating an opening mode failure on hydraulic fractures. Microseismic source mechanisms not only reveal important information about fracturing mechanisms, but also allow fracture characterization away from the wellbore, providing critical constraints for understanding fractured reservoirs.

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The relation between stimulated shear fractures and production in the Barnett Shale: Implications for unconventional oil and gas reservoirs

Geophysics ◽

10.1190/geo2018-0545.1 ◽

2019 ◽

Vol 84 (6) ◽

pp. B461-B469 ◽

Cited By ~ 2

Author(s):

Alex Hakso ◽

Mark Zoback

Keyword(s):

Hydraulic Fracturing ◽

Oil And Gas ◽

Shear Fracture ◽

Fracture Network ◽

Early Years ◽

Barnett Shale ◽

Hydraulic Fractures ◽

Low Permeability ◽

Distributed Temperature Sensing ◽

Fracture Planes

Economic production from extremely low permeability unconventional reservoirs is accomplished through multistage slick water hydraulic fracturing, which generates opening-mode hydraulic fractures and induces shear slip on preexisting fractures in the surrounding formation. We have addressed the critical contribution of the stimulated shear fracture network on production. We found production decline curves from tens of thousands of wells in four unconventional plays in the U.S. (two oil and two gas). These data indicate that during the early years of production: (1) Production is dominated by linear flow from the extremely low permeability matrix into much more permeable fracture planes, (2) the rapid decrease in production rates is a natural consequence of pressure depletion in the matrix within several meters of the more permeable planes, and (3) the cumulative area of permeable fracture planes created during stimulation is an important factor affecting cumulative production. Using data from two case studies in the Barnett Shale, we estimate the area of the fracture network from the microseismicity generated during hydraulic fracturing operations. The data from one study demonstrates that the cumulative area of the shear fracture network is needed to match production data. With data from the other case study, we demonstrate that the relative fracture area created during each stage correlates well with the relative stage-by-stage production determined from distributed temperature sensing.

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A Case Study Using Integrated Multi Disciplinary Approach to Model Microseismic Events During Stimulation

10.2118/204856-ms ◽

2021 ◽

Author(s):

Ghazal Izadi ◽

Colleen Barton ◽

Pierre-Francois Roux ◽

Tebis Llobet ◽

Thiago Pessoa ◽

...

Keyword(s):

Hydraulic Fracturing ◽

Hydraulic Fracture ◽

Fracture Propagation ◽

Natural Fracture ◽

Fracture Model ◽

Hydraulic Fractures ◽

Natural Fractures ◽

Unconventional Reservoir ◽

Geological Conditions ◽

Source Mechanisms

Abstract For tight reservoirs where hydraulic fracturing is required to enable sufficient fluid mobility for economic production, it is critical to understand the placement of induced fractures, their connectivity, extent, and interaction with natural fractures within the system. Hydraulic fracture initiation and propagation mechanisms are greatly influenced by the effect of the stress state, rock fabric and pre-existing features (e.g. natural fractures, faults, weak bedding/laminations). A pre-existing natural fracture system can dictate the mode, orientation and size of the hydraulic fracture network. A better understanding of the fracture growth phenomena will enhance productivity and also reduce the environmental footprint as less fractures can be created in a much more efficient way. Assessing the role of natural fractures and their interaction with hydraulic fractures in order to account for them in the hydraulic fracture model is achieved by leveraging microseismicity. In this study, we have used a combination of borehole and surface microseismic monitoring to get high vertical resolution locations and source mechanisms. 3D numerical modelling of hydraulic fracturing in complex geological conditions to predict fracture propagation is essential. 3D hydraulic fracturing simulation includes modelling capabilities of stimulation parameters, true 3D fracture propagation with near wellbore 3D complexity including a coupled DFN and the associated microseismic event generation capability. A 3D hydraulic fracture model was developed and validated by matching model predictions to microseismic observations. Microseismic source mechanisms are leveraged to determine the location and geometry of pre-existing features. In this study, we simulate a DFN based on the recorded seismicity of multi stage hydraulic fractures in a horizontal well. The advanced 3D hydraulic fracture modelling software can integrate effectively and efficiently data from a variety of multi-disciplinary sources and scales to create a subsurface characterization of the unconventional reservoir. By incorporating data from 3D seismic, LWD/wireline, core, completion/stimulation monitoring, and production, the software generates a holistic reservoir model embedded in a modular, multi-physics software platform of coupled numerical solvers that capture the fundamental physics of the processes being modelled. This study illustrates the importance of a powerful software tool that captures the necessary physics of stimulation to predict the effects of various completion designs and thereby ensure the most accurate representation of an unconventional reservoir response to a stimulation treatment.

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GEODYNAMICS

GEODYNAMICS ◽

10.23939/jgd2011.02.066 ◽

2011 ◽

Vol 2(11)2011 (2(11)) ◽

pp. 66-68

Author(s):

А. R. Gnyp ◽

Keyword(s):

Vertical Plane ◽

Source Mechanism ◽

Local Source ◽

Horizontal Gradient ◽

Single Source ◽

Normal Faulting ◽

Vertical Movements ◽

Source Mechanisms

Three groups of recurrent earthquakes have been identified within the Mukacheve series of 2005–2006. After relocation with application of differential arrivals and station terms their sources arranged into almost a vertical plane along the azimuth of ~120°, approximately coinciding with a plane of normal faulting determined for all the earthquakes as a single source mechanism. The results are consistent with data on some other local source mechanisms as also on an ambient field of extensional stresses in the local crust and a significant horizontal gradient of vertical movements across the epicenter area of the series.

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