Ergodic geophysical data acquisition design
Inventors
Assignees
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Publication Number
US-12189073-B2
Publication Date
2025-01-07
Expiration Date
Abstract
Determining locations to gather information to reduce the number of locations without reducing the information gathered is of key importance when such observations require drilling or other resource-intensive activities. By utilizing ergodic sampling, the same information (volume and/or resolution) may be obtained when compared to an exhaustive grid approach but with significantly fewer observations.
Core Innovation
The invention relates to determining a property of a subsurface volume by using an acquisition design based on an ergodic pattern. A surface area overlaying the subsurface volume is determined, and an ergodic pattern is calculated as a set of locations on the surface area. Observed data are obtained from the subsurface volume at each location in the set, and the property of the subsurface volume is determined from the observed data.
The ergodic pattern is selected using an optimization equation that maximizes a weighted similarity function S. The similarity function is selected from entropy, cross-correlation, L1 norm, and L2 norm. The optimization uses interval distribution of all sample pairs, angle distribution of all sample pairs, a sample density function, and terms associated with a spectral resolution function (SRF).
The design enables selecting an irregular pattern of sensing locations instead of a dense regular grid while aiming to preserve information and resolution through ergodicity-based sampling. Acquisition can be performed using concurrent multi-sensor substantially concurrently at corresponding locations or by sequentially traversing the locations to obtain portions of the observed data.
Claims Coverage
The document includes three independent claims: a method claim, a system claim implemented with microprocessor instructions, and a means-plus-functional system claim. Across these independent claims, the core coverage centers on determining an overlaying surface area, calculating an ergodic pattern of surface locations using an optimization equation with similarity and SRF-related terms, obtaining observed data at those locations, and determining the subsurface property from the observed data.
Ergodic subsurface property determination using overlay surface locations
Determining a surface area overlaying the subsurface volume; calculating an ergodic pattern comprising a set of locations on the surface area; obtaining observed data from the subsurface volume at each of the set of locations; and determining, from the observed data, the property of the subsurface volume.
Selecting an ergodic pattern by maximizing a weighted similarity function with SRF-related terms
Selecting the set of locations in accordance with the equation Φ*=arg max Φ²[ωα²S¹(αΦ,αθ)+ωβ²S¹(βΦ,βθ)+ωγ²S¹(γΦ,γθ)+μΦ²S¹(ξΦ,0)], wherein S is selected from entropy, cross-correlation, L1 norm, and L2 norm; α is interval distribution of all sample pairs; β is angle distribution of all sample pairs; γ is sample density function; ξ and μ are spectral resolution function (SRF)-related parameters; and δ is sample percentage.
Microprocessor-based implementation of ergodic pattern selection and subsurface determination
Performing, by at least one microprocessor coupled with a computer memory comprising computer readable instructions, determining a surface area overlaying the subsurface volume; calculating an ergodic pattern comprising a set of locations on the surface area; obtaining observed data from the subsurface volume at each of the set of locations; and determining, from the observed data, the property of the subsurface volume.
Means-based ergodic subsurface property determination using the SRF-weighted optimization
Means to determine a surface area overlaying the subsurface volume; means to calculate an ergodic pattern comprising a set of locations on the surface area; means to obtain observed data from the subsurface volume at each of the set of locations; and means to determine, from the observed data, the property of the subsurface volume, with the ergodic pattern selected in accordance with the weighted similarity optimization using SRF-related parameters.
The inventive coverage is unified by an ergodic sampling design: an overlay surface area is defined, an ergodic pattern of sensing locations is calculated by maximizing a weighted similarity function S that uses interval distribution, angle distribution, sample density function, and spectral resolution function (SRF) parameters, observed subsurface data are obtained at the selected locations, and a subsurface property is determined from those observed data.
Stated Advantages
Resource savings versus exhaustive dense-grid (Shannon–Nyquist/Nyquist) sampling while preserving information and resolution.
Documented Applications
No documented applications found
Interested in licensing this patent?