Reservoir Characterization
Understanding reservoir properties, geometry and fluid pressures is crucial for optimizing operations and minimizing risk. Our approach relies on monitoring deformation at shallow depths during well operations to reduce the need for deep wells that may be costly and damage your asset.
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We have used shallow deformation measurements to characterize the properties and geometry of a reservoir in Oklahoma during water injection. By measuring the strain at 30 m depth during injection at 500 m, we were able to characterize the hydraulic diffusivity, distance to reservoir boundaries, and fluid pressure distribution.
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This approach is similar to conventional Pressure Transient Analysis (PTA), but allows for near real-time pressure monitoring without reservoir monitoring wells.
Reservoir Surveillance
Measuring the strain tensor may enable the detection and location of changes in pressure at great distances away. This was demonstrated through a blind test, where we able to determine the presence and location of an operating well (1A) installed over 1 km away with no prior knowledge of the existence of the well.
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The well was located by plotting the strain tensor in map view.
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Leaks from geologic storage reservoirs are expected to produce similar signals, making strain tensor monitoring an invaluable tool for geologic storage monitoring.
Bayesian Inversion
Bayesian inversion is a method for estimating subsurface properties by combining measured data with physical models, while rigorously accounting for uncertainty. It’s especially valuable in complex environments where many different subsurface scenarios could explain the same data.
At Tensora, we use Bayesian inversion powered by physics-informed machine learning proxy models to efficiently explore a wide range of geologic and operational conditions. By applying this approach to strain data from our sensors, we generate probabilistic estimates of key model parameters—like permeability, stiffness, or injection zone geometry—along with quantified uncertainties. This enables our clients to make better-informed decisions with a clear understanding of risk.
History Matching Strain from Well Tests
Reservoir Properties from History Matching
Estimates of reservoir properties with uncertainty provided by Bayesian inversion of shallow strain during well tests.
(Roudini, 2023)
Publications
Journal of Hydrology (2025)
Geomechanics for Energy and the Environment (2023)
Water Resources Research (2023)
Water Resources Research (2021)
Water Resources Research (2020)