Interpretation and inversion of low‐frequency head observations

Vasco, D. W.; Karasaki, Kenzi

doi:10.1029/2005wr004445

Cited by 28 publications

(19 citation statements)

References 45 publications

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“…This term is evaluated for all the sources and sinks simultaneously by running the simulation model at the operating conditions. For details refer to the Vasco et al, [10,11].…”

Section: Bottom-hole Pressure Inversion Of Co 2 Injectormentioning

confidence: 97%

“…1) assumes the following form [14,11,15] ( ) (10) where (x) is the phase of the propagating pressure front. The motivation for using expansion of ( ) ω , x P (Eq.…”

Section: Pressure Peak Arrival Time Inversion Of Observation Wellsmentioning

confidence: 99%

“…1). This approach is selected for BHP inversion because it is computationally efficient as the inverse modelling only requires the solution of two problems which are equivalent to the steady state equation [11].…”

Section: Bottom-hole Pressure Inversion Of Co 2 Injectormentioning

confidence: 99%

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Bottom-hole Pressure Data Integration for CO2 Sequestration in Deep Saline Aquifers

2014

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We describe a novel approach to update geological models using bottom-hole pressure data from injection and observation wells during CO 2 sequestration. Our proposed history matching workflow, in conjunction with compositional simulations of supercritical CO 2 injection into a saline formation, involves: (a) inversion of zeroth order frequency of the injection-well pressure to modify the spatial permeability field around the injection well, (b) transient pressure arrival time inversion of observation well pressures to modify the inter-well spatial permeability field, and (c) gradient-based minimization of pressure mismatch at all wells using a global permeability multiplier.The proposed approach has been demonstrated on 3-D synthetic models generated using well-log data from the Weaber-Horn well in the Illinois basin. In this case supercritical CO 2 is injected for 11 months into a centrally located well, with pressure response monitored during injection and 1 month of shut-in at three observation wells. Injection is assumed to take place in a high-permeability layer close to the bottom of the model, with pressure responses monitored at all three observation wells only in the injection layer. Forecasts of pressure response at injection/observation wells over a three-year injection period produced with the inverted model also agree well with those from the reference model. Inversion of the 3-D model is more challenging and suffers from non-uniqueness, unless the condition of proximity to the prior model is imposed. In all cases, improved forecast of the CO 2 plume evolution was observed after the pressure history matching. We also show how the integration of time-lapse seismic data into the inversion process results in further improvement in gas saturation forecast. A systematic and efficient approach to integration of pressure data from CO 2 injection operations is presented, offering improved CO 2 plume prediction -especially when time-lapse seismic data is not available.

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“…This term is evaluated for all the sources and sinks simultaneously by running the simulation model at the operating conditions. For details refer to the Vasco et al, [10,11].…”

Section: Bottom-hole Pressure Inversion Of Co 2 Injectormentioning

confidence: 97%

“…1) assumes the following form [14,11,15] ( ) (10) where (x) is the phase of the propagating pressure front. The motivation for using expansion of ( ) ω , x P (Eq.…”

Section: Pressure Peak Arrival Time Inversion Of Observation Wellsmentioning

confidence: 99%

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Bottom-hole Pressure Data Integration for CO2 Sequestration in Deep Saline Aquifers

2014

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“…Compared to traditional 'amplitude inversion', the travel time inversion has been shown to have favorable quasilinear properties that ensures rapid convergence . We carry out matching of the flowing bottom-hole pressure data in the frequency domain following the procedure outlined by Vasco and Karasaki (2006).…”

Section: Production Data Integrationmentioning

confidence: 99%

Optimal Waterflood Management Under Geologic Uncertainty Using Rate Control: Theory and Field Applications

Alhuthali

2009

SPE Annual Technical Conference and Exhibition

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Waterflood optimization via rate control is receiving increased interest because of rapid developments in the smart well completions and I-field technology. The use of inflow control valves (ICV) allows us to optimize the production/injection rates of various segments along the wellbore, thereby maximizing sweep efficiency and delaying water breakthrough. It is well recognized that field scale rate optimization problems are difficult because they often involve highly complex reservoir models, production and facilities related constraints and a large number of unknowns. Some aspects of the optimization problem have been studied before using mainly optimal control theory.However, the applications to-date have been limited to rather small problems because of the computation time and the complexities associated with the formulation and solution of adjoint equations. Field-scale rate optimization for maximizing waterflood sweep efficiency under realistic field conditions has still remained largely unexplored.We propose a practical and efficient approach for computing optimal injection and production rates and thereby manage the waterflood front to maximize sweep efficiency and delay the arrival time to minimize water cycling. Our work relies on equalizing the arrival times of the waterfront at all producers within selected sub-regions of a water flood project. The arrival time optimization has favorable quasi-linear properties and the optimization proceeds smoothly even if our initial conditions are far from the solution. We account for geologic uncertainty using two optimization schemes.The first one is to formulate the objective function in a stochastic form which relies on a combination of expected value and standard deviation combined with a risk attitude iv coefficient. The second one is to minimize the worst case scenario using a min-max problem formulation. The optimization is performed under operational and facility constraints using a sequential quadratic programming approach. A major advantage of our approach is the analytical computation of the gradient and Hessian of the objective which makes it computationally efficient and suitable for large field cases.Multiple examples are presented to support the robustness and efficiency of the proposed optimization scheme. These include several 2D synthetic examples for validation purposes and 3D field applications.

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“…B. Vasco et al 2000, Vasco & Karasaki 2006, He et al 2006, Brauchler et al 2003, 2011. Die Inversion beruht dabei auf der Lösung eines Laufzeitintegrals, das den Zusammenhang zwischen der Laufzeit des Maximums einer aufgezeichneten instationären hydraulischen Druckänderung und der Diffusivität des untersuchten Systems beschreibt , Brauchler et al 2007.…”

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Bestimmung von hydraulischen Parametern in Lockergesteinen: Ein Vergleich unterschiedlicher Feldmethoden

Brauchler

Hu²,

Hu³

et al. 2012

Grundwasser

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ZusammenfassungIn dieser Feldstudie werden die laufzeitbasierte tomographische Inversion von Daten aus Kurzzeitpumpversuchen mit der analytischen Auswertung verglichen und die ermittelten hydraulischen Parameter hinsichtlich ihrer räumlichen Auflösung diskutiert und bewertet. Als Datenbasis dienen Messergebnisse aus Kurzzeitpumpversuchen, die in einer tomographischen Messanordnung in einem zwei Meter mächtigen, gut charakterisierten Sand-und Kiesgrundwasserleiter unter Verwendung eines 2"-Brunnens und eines Multikammerbrunnens, beide mit Direct-Push-Technik installiert, durchgeführt wurden. Die analytische Auswertung der Kurzzeitpumpversuche hat gezeigt, dass es nicht möglich ist, Bereiche mit unterschiedlichen hydraulischen Eigenschaften voneinander abzugrenzen. Entsprechend einem Vergleich mit den Ergebnissen von Multilevel-Slug-Tests werden die ermittelten hydraulischen Parameter, trotz einer geringen Pumpdauer von 200 Sekunden und hydraulisch isolierten Pump-und Beobachtungsintervallen, von einem hydraulisch höher durchlässigen Bereich am unteren Rand des Grundwasserleiters dominiert.Die laufzeitbasierte tomographische Inversion ermöglicht hingegen, vertikale und laterale Änderungen der Diffusivitätsverteilung zwischen Pump-und Beobachtungsbrunnen hochaufgelöst zu rekonstruieren. Investigation of hydraulic parameters in unconsolidated sediments: a comparison of methodsAbstract In this study the potential of a hydraulic traveltime based inversion approach with analytical solutions for the evaluation of short term pumping tests is assessed. The data base comprises measurements from short-term pumping tests performed in a sand and gravel aquifer using a tomographic measurement array. The evaluation, which is based on an analytical solution, has shown that it is not possible to delimit aquifer zones with different hydraulic properties. The comparison with multi-level slug tests has revealed that the pumping test results are dominated by a zone with a relatively high hydraulic conductivity located close to the bottom of the aquifer. This finding is surprising due to the short pumping time of 200 seconds and due to the hydraulically isolated pumping and observation intervals. The travel-time based inversion, however, allows the reconstruction of vertical and lateral changes in hydraulic diffusivity, between pumping and observation wells, with a high resolution.

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Interpretation and inversion of low‐frequency head observations

Cited by 28 publications

References 45 publications

Bottom-hole Pressure Data Integration for CO2 Sequestration in Deep Saline Aquifers

Bottom-hole Pressure Data Integration for CO2 Sequestration in Deep Saline Aquifers

Optimal Waterflood Management Under Geologic Uncertainty Using Rate Control: Theory and Field Applications

Bestimmung von hydraulischen Parametern in Lockergesteinen: Ein Vergleich unterschiedlicher Feldmethoden

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