On the use of quasi-static deformation to understand reservoir fluid flow

Geophysics ◽  
2005 ◽  
Vol 70 (4) ◽  
pp. O13-O27 ◽  
Author(s):  
Don W. Vasco ◽  
Alessandro Ferretti
Keyword(s):  
Fluid Flow ◽  
Surface Deformation ◽  
Equations Of Motion ◽  
Time Lapse ◽  
Oil Field ◽  
Static Deformation ◽  
Flow Properties ◽  
Reservoir Volume ◽  
Reservoir Permeability ◽  
Surface Displacements

Deformation above a producing reservoir provides a valuable source of information concerning fluid flow and flow properties. Quasi-static deformation occurs when the displacements are so slow that we may neglect inertial terms in the equations of motion. We present a method for inferring reservoir volume change and flow properties, such as permeability, from observations of quasi-static deformation. Such displacements may represent surface deformation such as tilt, leveling, interferometric synthetic aperture radar (InSAR), or bathymetry observations or subsurface deformation, as inferred from time-lapse seismic surveys. In our approach, the equation for fluid flow in a deforming reservoir provides a mapping from estimated fractional volume changes to reservoir permeability variations. If the reservoir behaves poroelastically over the interval of interest, all the steps in this approach are linear. Thus, the inference of reservoir permeability from deformation data becomes a linear inverse problem. In an application to the Wilmington oil field in California, we find that observed surface displacements, obtained by leveling and InSAR, are indeed compatible with measured reservoir volume fluxes. We find that the permeability variations in certain layers coincide with fault-block boundaries suggesting that, in some cases, faults are controlling fluid flow at depth.

scholarly journals Seismic imaging of reservoir flow properties: Resolving water influx and reservoir permeability

Geophysics ◽  
2008 ◽  
Vol 73 (1) ◽  
pp. O1-O13 ◽  
Author(s):  
D. W. Vasco ◽  
Henk Keers ◽  
Jalal Khazanehdari ◽  
Anthony Cooke
Keyword(s):  
Effective Means ◽  
Time Lapse ◽  
Multiple Time ◽  
Upward Movement ◽  
Model Assessment ◽  
Flow Properties ◽  
Model Parameter ◽  
Water Influx ◽  
Reservoir Permeability ◽  
Reservoir Flow

Methods for geophysical-model assessment — in particular, the computation of model-parameter resolution — indicate the value and the limitations of time-lapse data in estimating reservoir flow properties. A trajectory-based method for computing sensitivities provides an effective means to compute model-parameter resolution. We examine the common situation in which water encroaches into a reservoir from below, as caused by the upward movement of an oil-water contact. Though the techniques described are not limited to this case, we treat the situation in which the time-lapse response is primarily caused by changes in saturation. Using straightforward techniques, we find that, by including reflections off the top and bottom of a reservoir tens of meters thick, we can infer reservoir permeability based upon time-lapse data. We find that, for the case of water influx from below, using multiple time-lapse snapshots does not necessarily improve the resolution of reservoir permeability. An application to time-lapse data from the Norne field in the North Sea illustrates that we can resolve the permeability near a producing well using reflections from three interfaces associated with the reservoir.

scholarly journals Seismic imaging of reservoir flow properties: Time‐lapse amplitude changes

Geophysics ◽  
2004 ◽  
Vol 69 (6) ◽  
pp. 1425-1442 ◽  
Author(s):  
Don W. Vasco ◽  
Akhil Datta‐Gupta ◽  
Ron Behrens ◽  
Pat Condon ◽  
James Rickett
Keyword(s):  
Seismic Data ◽  
Large Scale ◽  
Seismic Imaging ◽  
Asymptotic Methods ◽  
Time Lapse ◽  
Flow Properties ◽  
Reservoir Permeability ◽  
Amplitude Data ◽  
Reservoir Flow ◽  
Iterative Inversion

Asymptotic methods provide an efficient means by which to infer reservoir flow properties, such as permeability, from time‐lapse seismic data. A trajectory‐based methodology, similar to ray‐based methods for medical and seismic imaging, is the basis for an iterative inversion of time‐lapse amplitude changes. In this approach, a single reservoir simulation is required for each iteration of the algorithm. A comparison between purely numerical and the trajectory‐based sensitivities demonstrates their accuracy. Analysis of a set of synthetic amplitude changes indicates that we are able to recover large‐scale reservoir permeability variations from time‐lapse amplitude data. In an application to actual time‐lapse amplitude changes from the Bay Marchand field in the Gulf of Mexico, we are able to reduce the misfit by 81% in 12 iterations. The time‐lapse observations indicate lower permeabilities are required in the central portion of thereservoir.

scholarly journals Inflating Shallow Plumbing System of Bezymianny Volcano, Kamchatka, Studied by InSAR and Seismicity Data Prior to the 20 December 2017 Eruption

2021 ◽  
Vol 9 ◽  
Author(s):  
René Mania ◽  
Simone Cesca ◽  
Thomas R. Walter ◽  
Ivan Koulakov ◽  
Sergey L. Senyukov
Keyword(s):  
Surface Deformation ◽  
Low Frequency ◽  
Time Lapse ◽  
Plumbing System ◽  
Bezymianny Volcano ◽  
Magma Plumbing System ◽  
Seismic Amplitude ◽  
Surface Displacements ◽  
Deep Seismicity ◽  
Magma Plumbing

Explosive eruptions at steep-sided volcanoes may develop with complex precursor activity occurring in a poorly-understood magma plumbing system so that timelines and possible interactions with the geologic surrounding are often unresolved. Here we investigate the episode prior to the energetic December 20, 2017 eruption at Bezymianny volcano, Kamchatka. We compare degassing activity inferred from time-lapse camera images, seismicity and real-time seismic amplitude (RSAM) data derived from a temporary station network, as well as high-resolution InSAR displacement maps. Results show that the first changes can be identified in low-frequency seismicity and degassing at least 90 days before the eruption, while the first volcano-tectonic (VT) seismicity occurred 50 days before the eruption. Coinciding with significant changes of the RSAM, surface displacements affect the volcanic flanks at least 9 days prior to the eruption. Inversion modeling of the pre-eruptive surface deformation as well as deflation-type, co-eruptive surface changes indicate the presence of a shallow and transient reservoir. We develop a conceptual model for Bezymianny volcano initiating with deep seismicity, followed by shallow events, rockfalls, steaming and an inflating reservoir. The eruption is then associated with subsidence, caused by deflation of the same reservoir. This sequence and conceivable causality of these observations are providing a valuable contribution to our understanding of the shallow magma plumbing system beneath Bezymianny and may have relevance for volcano monitoring and early warning strategies at similar volcanoes elsewhere.

Time‐lapse crosswell seismic tomography to characterize flow structure in the reservoir during the thermal stimulation

Geophysics ◽  
1995 ◽  
Vol 60 (3) ◽  
pp. 660-666 ◽  
Author(s):  
Doo Sung Lee ◽  
Veronica M. Stevenson ◽  
Phil F. Johnston ◽  
C. E. Mullen
Keyword(s):  
Fluid Flow ◽  
Flow Structure ◽  
Seismic Tomography ◽  
Thermal Response ◽  
Time Lapse ◽  
Tracer Test ◽  
Heat Propagation ◽  
Oil Field ◽  
Thermal Stimulation ◽  
Fluid Temperature

Time‐lapse crosswell seismic tomography data, recorded with an interval of six months, indicate a strong directional thermal response in a fractured eolian sandstone reservoir at a five‐spot thermal stimulation site in the South Casper Creek oil field, Wyoming. The seismic thermal response depicted on the tomogram and in conjunction with the geological data from cores and a wireline log, reveals the multichannel flow mechanism in the reservoir formation. The three factors that control steam or heat propagation are the fractures, the directional permeability existing in the rock matrix, and the fault. Crosswell tomograms imply that the primary fluid flow is through fractures oriented north‐south, whereas the secondary fluid flow is through the matrix in the direction of maximum horizontal permeability. The thermal response expressed on the tomogram infers that a fault oriented N80°E offsets flow units and acts as a flow barrier or baffle. The flow structure implied by the crosswell seismic tomography is strikingly different from the initial conjecture, as deduced from engineering perception based on geological reasoning. However, the tomographic implications were supported by both a tracer test and fluid temperature measurements at the four producing wells around the injector.

Using surface deformation to image reservoir dynamics

Geophysics ◽  
2000 ◽  
Vol 65 (1) ◽  
pp. 132-147 ◽  
Author(s):  
Don W. Vasco ◽  
Kenzi Karasaki ◽  
Christine Doughty
Keyword(s):  
Volume Change ◽  
Large Scale ◽  
Surface Deformation ◽  
Test Site ◽  
Oil Field ◽  
Volume Changes ◽  
Reservoir Volume ◽  
Steam Flood ◽  
Inversion Procedure ◽  
Sudden Decrease

The inversion of surface deformation data such as tilt, displacement, or strain provides a noninvasive method for monitoring subsurface volume change. Reservoir volume change is related directly to processes such as pressure variations induced by injection and withdrawal. The inversion procedure is illustrated by an application to tiltmeter data from the Hijiori test site in Japan. An inversion of surface tilt data allows us to image flow processes in a fractured granodiorite. Approximately 650 barrels of water, injected 2 km below the surface, produces a peak surface tilt of the order of 0.8 microradians. We find that the pattern of volume change in the granodiorite is very asymmetrical, elongated in a north‐northwesterly direction, and the maximum volume change is offset by more than 0.7 km to the east of the pumping well. The inversion of a suite of leveling data from the Wilmington oil field in Long Beach, California, images large‐scale reservoir volume changes in 12 one‐ to two‐year increments from 1976 to 1996. The influence of various production strategies is seen in the reservoir volume changes. In particular, a steam flood in fault block II in the northwest portion of the field produced a sudden decrease in reservoir volume.

scholarly journals Seismic imaging of reservoir flow properties: Time‐lapse pressure changes

Geophysics ◽  
2004 ◽  
Vol 69 (2) ◽  
pp. 511-521 ◽  
Author(s):  
Don W. Vasco
Keyword(s):  
Sparse Matrix ◽  
Fluid Pressure ◽  
Linear Partial Differential Equation ◽  
Time Lapse ◽  
Flow Properties ◽  
Linear Inverse Problem ◽  
Reservoir Permeability ◽  
Reservoir Flow ◽  
Sparse Matrix Techniques ◽  
Pressure Changes

Time‐lapse fluid pressure and saturation estimates are sensitive to reservoir flow properties such as permeability. In fact, given time‐lapse estimates of pressure and saturation changes, one may define a linear partial differential equation for permeability variations within the reservoir. The resulting linear inverse problem can be solved quite efficiently using sparse matrix techniques. An application to a set of crosswell saturation and pressure estimates from a CO2 flood at the Lost Hills field in California demonstrates the utility of this approach. The pressure and saturation estimates are mapped into reservoir permeability variations between the boreholes. The resulting permeability estimates agree with a permeability log in an adjacent well and are in accordance with water and CO2 saturation changes imaged in the interwell region.

Dual attenuation peaks revealing mesoscopic and microscopic fluid flow in partially oil-saturated Fontainebleau sandstones

2020 ◽  
Vol 224 (3) ◽  
pp. 1670-1683
Author(s):  
Liming Zhao ◽  
Genyang Tang ◽  
Chao Sun ◽  
Jianguo Zhao ◽  
Shangxu Wang
Keyword(s):  
Fluid Flow ◽  
Reservoir Characterization ◽  
Seismic Analysis ◽  
Confining Pressure ◽  
Time Lapse ◽  
Seismic Attenuation ◽  
Fluid Distribution ◽  
Oil Viscosity ◽  
Measurement Results ◽  
And Shifts

SUMMARY We conducted stress–strain oscillation experiments on dry and partially oil-saturated Fontainebleau sandstone samples over the 1–2000 Hz band at different confining pressures to investigate the wave-induced fluid flow (WIFF) at mesoscopic and microscopic scales and their interaction. Three tested rock samples have similar porosity between 6 and 7 per cent and were partially saturated to different degrees with different oils. The measurement results exhibit a single or two attenuation peaks that are affected by the saturation degree, oil viscosity and confining pressure. One peak, exhibited by all samples, shifts to lower frequencies with increasing pressure, and is mainly attributed to grain contact- or microcrack-related squirt flow based on modelling of its characteristics and comparison with other experiment results for sandstones. The other peak is present at smaller frequencies and shifts to higher frequencies as the confining pressure increases, showing an opposite pressure dependence. This contrast is interpreted as the result of fluid flow patterns at different scales. We developed a dual-scale fluid flow model by incorporating the squirt flow effect into the patchy saturation model, which accounts for the interaction of WIFFs at microscopic and mesoscopic scales. This model provides a reasonable interpretation of the measurement results. Our broad-frequency-band measurements give physical evidence of WIFFs co-existing at two different scales, and combining with modelling results, it suggests that the WIFF mechanisms, related to pore microstructure and fluid distribution, interplay with each other and jointly control seismic attenuation and dispersion at reservoir conditions. These observations and modelling results are useful for quantitative seismic interpretation and reservoir characterization, specifically they have potential applications in time-lapse seismic analysis, fluid prediction and reservoir monitoring.

scholarly journals Near-surface real-time seismic imaging using parsimonious interferometry

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sherif M. Hanafy ◽  
Hussein Hoteit ◽  
Jing Li ◽  
Gerard T. Schuster
Keyword(s):  
Fluid Flow ◽  
Real Time ◽  
Temporal Resolution ◽  
Seismic Imaging ◽  
Time Lapse ◽  
Rock Properties ◽  
Recording Time ◽  
Near Surface ◽  
Arrival Times ◽  
Order Of Magnitude

AbstractResults are presented for real-time seismic imaging of subsurface fluid flow by parsimonious refraction and surface-wave interferometry. Each subsurface velocity image inverted from time-lapse seismic data only requires several minutes of recording time, which is less than the time-scale of the fluid-induced changes in the rock properties. In this sense this is real-time imaging. The images are P-velocity tomograms inverted from the first-arrival times and the S-velocity tomograms inverted from dispersion curves. Compared to conventional seismic imaging, parsimonious interferometry reduces the recording time and increases the temporal resolution of time-lapse seismic images by more than an order-of-magnitude. In our seismic experiment, we recorded 90 sparse data sets over 4.5 h while injecting 12-tons of water into a sand dune. Results show that the percolation of water is mostly along layered boundaries down to a depth of a few meters, which is consistent with our 3D computational fluid flow simulations and laboratory experiments. The significance of parsimonious interferometry is that it provides more than an order-of-magnitude increase of temporal resolution in time-lapse seismic imaging. We believe that real-time seismic imaging will have important applications for non-destructive characterization in environmental, biomedical, and subsurface imaging.

scholarly journals Reservoir-Induced Land Deformation: Case Study from the Grand Ethiopian Renaissance Dam

2021 ◽  
Vol 13 (5) ◽  
pp. 874
Author(s):  
Yu Chen ◽  
Mohamed Ahmed ◽  
Natthachet Tangdamrongsub ◽  
Dorina Murgulet
Keyword(s):  
Land Surface ◽  
Large Scale ◽  
Surface Deformation ◽  
Vertical Displacement ◽  
Nile River ◽  
Reservoir Volume ◽  
Novel Approach ◽  
Land Deformation ◽  
Large Scale Land ◽  
The Impact

The Nile River stretches from south to north throughout the Nile River Basin (NRB) in Northeast Africa. Ethiopia, where the Blue Nile originates, has begun the construction of the Grand Ethiopian Renaissance Dam (GERD), which will be used to generate electricity. However, the impact of the GERD on land deformation caused by significant water relocation has not been rigorously considered in the scientific research. In this study, we develop a novel approach for predicting large-scale land deformation induced by the construction of the GERD reservoir. We also investigate the limitations of using the Gravity Recovery and Climate Experiment Follow On (GRACE-FO) mission to detect GERD-induced land deformation. We simulated three land deformation scenarios related to filling the expected reservoir volume, 70 km3, using 5-, 10-, and 15-year filling scenarios. The results indicated: (i) trends in downward vertical displacement estimated at −17.79 ± 0.02, −8.90 ± 0.09, and −5.94 ± 0.05 mm/year, for the 5-, 10-, and 15-year filling scenarios, respectively; (ii) the western (eastern) parts of the GERD reservoir are estimated to move toward the reservoir’s center by +0.98 ± 0.01 (−0.98 ± 0.01), +0.48 ± 0.00 (−0.48 ± 0.00), and +0.33 ± 0.00 (−0.33 ± 0.00) mm/year, under the 5-, 10- and 15-year filling strategies, respectively; (iii) the northern part of the GERD reservoir is moving southward by +1.28 ± 0.02, +0.64 ± 0.01, and +0.43 ± 0.00 mm/year, while the southern part is moving northward by −3.75 ± 0.04, −1.87 ± 0.02, and −1.25 ± 0.01 mm/year, during the three examined scenarios, respectively; and (iv) the GRACE-FO mission can only detect 15% of the large-scale land deformation produced by the GERD reservoir. Methods and results demonstrated in this study provide insights into possible impacts of reservoir impoundment on land surface deformation, which can be adopted into the GERD project or similar future dam construction plans.

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