UT Shield

Formation Evaluation

Joint Industry Research Consortium

Research Description

2023 FE Consortium Current and Future Proposed Research

Scope of Work for Future Activities and Developments

The lists below itemize future work for 3D UTAPWeLS software and ongoing research projects.  We also list the most significant improvement and accomplishments.   A breakdown of software modules and research projects is summarized along with our vision of research and development for upcoming consortium activities.

Some future projects related to the energy transition:

1.      Extreme Petrophysics and Formation Evaluation of geothermal reservoir appraisal and development. This effort includes new high-pressure and high-temperature measurements of rock properties.
2.       New methods for real-time well-geosteering in harsh subsurface environments based on the 3D interpretation of deep-sensing electromagnetic and elastic measurements.
3.       New methods for chemical and physical analysis of mud properties (mud logging) for geothermal drilling applications.
4.       Monitoring of CO2 sequestration and hydrogen-storage projects with fiber-optics sensors.
5.       Implementation of artificial intelligence, machine learning, and data science methods for intelligent borehole measurement acquisition and interpretation in geothermal and CO2 sequestration projects.
6.       Modulated drilling vibrations for real-time, at-the-bit assessment of rock mechanical properties in harsh subsurface environments for geothermal, hydrogen and CO2 sequestration projects.

 Itemized list of the most significant improvements of 3D UTAPWeLS resulting from 2020-2021 work:

  1. Reengineering of the Nuclear Logging Simulator
    1. Radial invasion profiles are now considered for all the simulations, wireline or LWD.
    2. Mudcake buildup and washouts are accounted for in all the numerical simulations.
    3. Reduced calculation times by 20%.
  2. NMR Studio
    1. Mudcake buildup and washouts are accounted for in the numerical simulator.
    2. NMR inversion analysis.
  3. Markov-Chain Monte Carlo (MCMC) Inversion
    1. Streamlined the algorithms used to simultaneously estimate layer-by-layer properties and their uncertainties.
    2. Added borehole corrections for intervals where either caliper, cable tension, cable speed, or delta density logs indicate unreliable or noisy measurement conditions.
  4. Joint Inversion of Multiple Well Logs to Estimate Rock Solid/Fluid Composition
    1. Implemented a surrogate model that makes inversion significantly faster.
    2. Included multivariate priors to improve the accuracy and reliability of inversion results.
  5. Petrophysical Calculations
    1. It is now possible to enforce either Thomas-Stieber’s relationships (for the case of clastic sedimentary sequences), or/and to honor volumetric constraints in any petrophysical layer.
    2. Pore and overburden pressure calculator based on fluid saturations.
  6. Multi-Well Analysis
    1. Formation zones can be defined in each well, providing the foundation for multi-well data comparison, visualization, and inversion.
    2. Mnemonic groups are now defined to enable multi-well visualization of equivalent logging curves. They are a basic building block for multi-well data analysis, inversion of earth model properties, and for enhancing the connectivity of a number of other software modules.
  7. Multi-Well Data Visualization
    1. Reengineered the cross-plot module with a multi-well perspective.
    2. Introduced a new module for multi-well data quality control, which enables the construction of Box plots, histograms, and cross plots.
  8. Updated the Matlab Version.
    1. Using Matlab version 2021a allows the user to access newly developed Matlab toolboxes, several of which with machine-learning focus.

Our upcoming future plans for 3D UTAPWeLS development include the following items:

  1. Expand the inversion capabilities for multi-measurement and multi-well concurrent processing. Among multiple strategies, we already started to implement an expert-consensus strategy.
  2. Develop and implement more integrated 3D model-based inversion algorithms for automatic interpretation of well logs.
  3. Develop a module for automatic (machine learning) rock classification, while allowing the user to further refine the classification through cross plots or track display.
  4. Develop a new module to compare and transfer properties from multiple wells.
  5. Reengineer the invasion and formation-testing module, and back-end simulator (Fortran). We plan to parallelize this simulator to reduce CPU times, and refine input parameters to avoid unnecessary long execution times.
  6. Implement a fast 3D sonic simulator.
  7. Expand plots available in the track display, one to show text, and one to show probabilities of earth model properties through a heat map.
  8. Implement a table view for well logs where individual data points can be edited, as well as the well-log’s metadata, e.g., raw units and name.
  9. A module to optimize field-specific databases (e.g., calcite’s Th, K, and U responses) based on data available in a key well with the greatest amount and diversity of borehole measurements.
  10. Simplify module execution for multiple wells in parallel, e.g., petrophysical calculations, inversion algorithms, and bed-boundary detection.
  11. Visual programming for multi-well interpretation workflows, especially workflows based on the inversion of layer-by-layer properties. This will be a simple and intuitive module to organize workflows to run in parallel for multiple wells.
  12. 3D UTAPWeLS in the cloud.
  13. Continue improving the user friendliness of all modules.
  14. Continue expanding the available scripting capabilities.
  15. Include additional help functionality.

Future Developments to Software Modules:

SC0-0.       3D Petrophysics and Well-Log Simulation Platform (3D UTAPWeLS): 3D UTAPWeLS is a user-friendly, MATLAB-based integrated platform that a variety of modules into one single software utility for interactive 3D multi-well formation evaluation. The platform constructs multi-layer static and dynamic petrophysical models (also known as Common Stratigraphic Frameworks, CSF) that can be subject to reservoir and geophysical upscaling and that lend themselves to multiple-hypotheses testing, rock classification, cross-validation and numerical simulation and inversion of measurements. It also includes basic and advanced well-logging calculations, layer-boundary detection algorithms, basic digital signal processing routines, simulation of the process of mud-filtrate invasion in vertical wells with water- and oil-base muds, and numerical modeling/inversion of well logs for the estimation of layer-by-layer petrophysical properties. 3D UTAPWeLS interfaces the Borehole Resistivity, Borehole Sonic, Borehole Nuclear, Borehole NMR, Formation Testing, Invasion, and Pore-Level Petrophysics Modules described below. The software contains a 3D version of the CSF which allows the interactive construction, display, and management of 3D reservoir models penetrated by multiple wells with arbitrary trajectories. Multiple instances of UTAPWeLS can be spawned to detect and define bed boundaries and simulate well logs to quantify layer-by-layer properties within the 3D CSF.  Individual wells can also be duplicated to test different hypotheses on the same well, and they can be exported to files to be imported to other projects and other software platforms.

Future developments: (a) Module for automatic classification of rocks. (b) Enable the direct modification of global surfaces based on the 3D view of local intersections in well-log tracks.

  • Earth Model Construction Module: This software utility is dedicated to performing all processes associated with specifying and quantifying properties of the earth model. It includes: (a) Compositional Palette, where the solid/fluid composition of a layer is specified in detail, as well as its internal structure based on the sand-shale laminated system model described in the Thomas-Stieber diagram. (b) Petrophysical Calculator, to set earth-model properties through petrophysical calculations. (c) Table View, to allow convenient layer-by-layer viewing and editing of a variety of preset or custom property groups with an easy-to-use table. (d) Detect Bed Boundaries, to identify boundaries crossing the well trajectory based on well logs. (e) Populate Properties, to set earth-model properties based on well logs, including access to the Minerals Import window where spectral logs can be used to populate mineral compositions. (f) Well Geometry, to specify the geometry of the well trajectory and the crossings of bed boundaries. (g) 3D Geometry, to visualize and modify the well in a full 3D context with the aid of interactive 2D projection plots of the 3D geometry (slides or curtain, along the well trajectory).

Future developments: (a) Improve the population of earth model properties.

  • Log Studio Module: Comprehensive set of sub-modules intended to manipulate and calculate well logs. It includes: (a) Log Petrophysical Calculator, to perform pre-defined petrophysical calculations using well logs as input and output. (b) Custom Log Calculator, to perform user-defined calculations using well logs as input and output. (c) Depth Shift, to bulk shift, stretch, or squeeze well logs along their measured depth. (d) Filters, to apply signal processing filters to well logs.

Future developments: (a) Expand the set of predefined possible petrophysical calculations. (b) Include calculations with reference to the regional model in the 3D context. (c) Include calculations using data from different wells. (d) Include earth-model properties in the data options available for calculations.

  • Borehole Resistivity Module (BRM): 3D UTAPWeLS graphical interface for the processing, interpretation, numerical simulation, and inversion of borehole resistivity logs. The software allows vertical and deviated wells, arbitrary layers, and multiple radial zones of invasion, presence of resistivity anisotropy, electrical permittivity, and magnetic permeability.

Future developments: (a) Interactive inversion of raw (borehole corrected) and/or apparent resistivity measurements, both wireline and LWD acquired along arbitrary well trajectories. (b) 2.5D and 3D simulation of resistivity measurements. (c) Expand cross-functionality with Borehole Sonic Module, Borehole Nuclear Module, Borehole Sonic Module, and NMR Module. (d) Expand the tool scope and associated numerical simulations by including layers that are not being crossed by the well trajectory.

  • Borehole Sonic Module (BSM): UTAPWeLS graphical interface for the display, processing, interpretation, simulation, and inversion of time-domain sonic waveforms. The simulation software assumes a vertical well, either monopole or dipole acoustic sources/receivers or specific cylindrical tools, horizontal layers, and multiple radial zones of invasion.

Future developments: (a) Inversion of radial profiles of P-wave velocity, S-wave velocity, and density. (b) More efficient integration with Borehole Resistivity Module and Borehole Nuclear Module. (c) Implementation of fast numerical simulation of sonic logs in high-angle and horizontal wells.

  • Borehole Nuclear Module (BNM): 3D UTAPWeLS graphical interface for the display, processing, interpretation, numerical simulation, and inversion of borehole nuclear measurements. Numerical modeling is based on new linear iterative refinement approximations developed by the Consortium. The software assumes vertical or arbitrarily deviated wells with or without presence of mud-filtrate invasion. It includes measurement sensitivity functions calculated with MCNP for specific borehole environmental conditions and provided by oil-service companies. Nuclear properties input to the simulations of nuclear logs can be calculated with either Schlumberger’s SNUPAR, Weatherford’s WRAPM, or our newly developed open-source UTNuPro codes based on pressure, temperature, and chemical compositions and volumetric concentrations of mineral and fluid constituents.

Future developments: (a) Inclusion of additional commercial nuclear sensitivity functions. (b) Inversion of gamma-ray, density, PEF, and neutron logs (wireline and LWD) in deviated wells. (c) Combine deterministic and Bayesian inversion of nuclear and resistivity logs (LWD and wireline).  (d) Include simulation of open- and case-hole Sigma logs. (e) Include simulation of neutron-capture gamma-ray spectroscopy logs.

  • Borehole SP Simulator: 3D UTAPWeLS graphical interface for the 3D simulation of spontaneous potential (SP) logs. The algorithm invokes fundamental physics principles of membrane and diffusion potentials to simulate borehole SP measurements.

Future developments: (a) Include inversion algorithms for SP measurements.

  • Invasion Module (IM): 3D UTAPWeLS graphical interface for the 1D radial or 2D simulation of water- and oil-base mud-filtrate invasion. The corresponding effects on well logs and formation-tester measurements can then be analyzed in an interactive manner. The 1D and 2D software assumes a vertical well, horizontal layers, and constant or arbitrary petrophysical properties within each layer.

Future developments: (a) Expand the 2D multiphase simulator to include 3D geometries with improved performance and multi-CPU capabilities.

  • Formation Testing Module (FTM): 3D UTAPWeLS graphical interface for the display, processing, numerical simulation, interpretation, and inversion of formation-tester measurements. It includes 1D and 2D multi-phase simulators as well as a 3D single-phase simulator. Both dual-packer and point-probe formation testers (including focused point probes) can be invoked when performing the simulations. Custom tool parameters can be saved in a list of predefined tools for easy access.

Future developments: (a) Improve the efficiency of the numerical algorithm used to simulate point-probe measurements. (b) Improve the pressure transient analysis to include more automated results and better analysis tools.

  • Nuclear Magnetic Resonance Module (NMRM): 3D UTAPWeLS graphical interface for the display, processing, numerical simulation, interpretation, and inversion of magnetic resonance measurements. The software can calculate proton magnetization time decays based on user-defined sequences or calculate exponential distributions for all combinations of T1, T2, and T2a, and D measurements based on user-defined component distributions. These calculations consider Rock Class NMR settings for pore sizes and fluid properties. Additionally, the module can invert magnetization sequences for imported or Earth Model data, and can generate simulated NMR logging data from the Earth Model results. These options are accessible from the NMR Studio window. We added an Earth Model property for NMR Porosity as well for comparison to alternative porosity definitions and calculations.

Future developments: (a) Interactive matching of the measured T2 distributions with numerical simulations to determine dominant pore sizes and their variability. (b) Matching of magnetization time decays. (c) Improved scripting access to all capabilities. (d) Improved editing of component properties with NMR-grouped properties. (e) Integrated drilling-mud definitions to better account for borehole effects on NMR properties.

  • Inversion Resistivity Module: 3D UTAPWeLS module that allows estimation of earth-model resistivity values via inversion.

Future developments: (a) Include additional forward simulators to expand the set of tools that can be used in the inversion. (b) Enable automatic adjustments in the location of bed boundaries.

  • Markov-Chain Monte Carlo (MCMC) Inversion Module: 3D UTAPWeLS module that allows inversion of various earth-model properties. The user selects an input well log that is to be matched with a numerically simulated log by adjusting the corresponding earth model property via perturbations with a Markov-Chain method.

Future developments: (a) Expand the algorithm to allow for more properties to be inverted, such as SP. (b) Enable the inversion of multiple properties simultaneously, restricted only by the enforcement of the same set of bed boundaries. (c) Enable the addition or deletion of bed boundaries as part of the inversion. (d) Allow the modification of radial boundaries for 2D and 3D simulations as part of the inversion process. (e) Automate the estimation of sensitivity functions between logs, and layer properties to improve the inversion in anisotropic and/or invaded conditions.

  • Compositional Joint Inversion Module: 3D UTAPWeLS module that estimates petrophysical properties (e.g., porosity, water saturation, solid and fluid compositions) from physical properties (e.g., resistivity, density, gamma ray, etc.). Layer-by-layer physical properties need to be inverted from their associated measurements before using this module.

Future developments: (a) Expand the library of pre-calculations. (b) Perform concurrent, automatic adjustment of priors based on new data. (c) Enable field-specific libraries of priors.

  • Pore-Level Petrophysics Module (PLPM): 3D UTAPWeLS graphical interface for pore-level petrophysical analysis and quantification of (a) granular porous media, and (b) 3D CT rock images. Granular porous media are constructed by simulating the processes of sedimentation, compaction, and cementation of grain packs.

Future developments: (a) Calculate formation factor and resistivity index of grain packs constructed with grain-coating clay minerals. (b) Improve the interaction with other 3D UTAPWeLS modules. (c) Accelerate some of the algorithms. (d) Include a scripting interface.

2020-2021 Accomplishments

The following itemized list highlights the most important accomplishments achieved by the research consortium during the 2020-2021 cycle:

  1. Developed a new 3D fast numerical approximation to simulate deep-sensing LWD borehole electromagnetic measurements using the concept of spatially-adaptive tensorial sensitivity functions.
  2. Developed a new Bayesian inversion algorithm for the estimation of layer-by-layer invasion- and virgin-zone resistivities from any type of multi-resolution borehole resistivity measurements.
  3. Developed a new method for the rapid calculation of two-phase petrophysical properties of rocks exhibiting bimodal pore/throat-size distributions.
  4. Developed a new 3D algorithm for the rapid numerical simulation of P-wave sonic arrival times based on the eikonal equation. The algorithm is intended for the numerical simulation of sonic arrival times in high-angle and horizontal wells.
  5. Developed a new inversion-based procedure for the statistical assessment of storage and flow properties of thinly-bedded sedimentary rocks from basic and advanced well logs.
  6. Developed and verified a new machine-learning method for the automatic estimation of flow-related properties of rocks from well logs based on the physics of mud-filtrate invasion.
  7. Developed new machine-learning procedures for automatic well-log normalization and well-to-well correlation.
  8. Performed continuous, and angle-dependent ultrasonic reflectivity measurements on spatially complex rocks.
  9. Implemented X-ray radiography measurements for the quantification of two-phase petrophysical properties of grain-laminated rocks.
  10. Implemented molecular dynamics simulations for the study of solid-fluid and fluid-fluid surface effects on multi-frequency NMR measurements of tight rocks.

Future Work for Ongoing Research Projects:

The list below itemizes the future work for ongoing research projects. Projects are classified according to the standard designation of well logs and petrophysical applications; they summarize our vision of research and development for upcoming years of consortium activities.

Formation Testing

  • Numerical simulation and inversion of dual-packer and point-probe formation-tester measurements acquired in vertical and deviated wells in the presence of mud-filtrate invasion.

Future Work: (a) Develop flow-rate pulsing sequences for optimal estimation of petrophysical properties and expedient fluid sampling in the presence of spatially complex rocks. (b) Develop new method for the fast modeling and interpretation of optical fluid measurements.

Resistivity/SP Logs

  • 3D finite-difference and numerical mode-matching numerical simulation and inversion of triaxial borehole induction measurements acquired in horizontal and deviated wells.

Future Work: (a) Continue the development and testing of fast 3D algorithms for the inversion of triaxial LWD borehole induction measurements acquired in high-angle wells. (b) Develop fast gradient- and Bayesian-based methods for the pixel-based, 3D inversion of deep-sensing LWD tri-axial borehole electromagnetic measurements. (c) Include resistivity anisotropy in the 3D inversion of deep-sensing LWD tri-axial borehole electromagnetic measurements.

  • Deterministic and Stochastic inversion of resistivity logs acquired in vertical and deviated wells with appraisal of uncertainty.

Future Work: (a) Continue the development of 2.5D and 3D machine-learning algorithms for the expedient inversion of LWD resistivity logs in the presence of noise. (b) Develop fast gradient- and Bayesian-based methods for the pixel-based, 3D inversion of deep-sensing LWD tri-axial borehole electromagnetic measurements.

  • Efficient methods for multi-well resistivity modeling and inversion in the context of a 3D Common Stratigraphic Framework (CSF)

Future Work: (a) Continue the development of multi-well resistivity inversion algorithms to improve the construction of 3D CSFs. (b) Combine resistivity inversion algorithms with results obtained from the inversion of nuclear logs acquired along the same well trajectories.

 Simulation and interpretation of spontaneous potential (SP) logs.

Future Work: (a) Continue to perform laboratory experiments to quantify and verify SP phenomenological descriptions, especially in the presence of partial hydrocarbon saturation and variable rock wettability.

 Sonic Logs

  • 3D, 2.5D and 1.5D time-domain simulation and inversion of sonic waveforms acquired in elastic and poro-elastic formations with monopole, dipole, and quadrupole sources.

Future Work: (a) Develop a 2.5D finite-difference code for the simulation of sonic waveforms in poro-elastic media. (b) Improve the speed of computation of 3D codes.

  • 2D/3D finite-element, hp-adaptive, frequency-domain numerical simulation of borehole sonic measurements.

Future Work: (a) Develop a 3D algorithm to simulate sonic waveforms acquired in deviated wells with and without tool eccentricity.

  • Fast numerical simulation of sonic-slowness logs.

Future Work: (a) Continue to verify the fast sonic simulation methods with field examples, especially for wireline and LWD measurements acquired in high-angle and horizontal wells in the presence of anisotropy.

  • Fast inversion of sonic-slowness logs.

Future Work: (a) Continue the development of fast inversion methods for LWD and wireline P- and S-wave sonic logs acquired in high-angle wells.

Nuclear Logs

  • Monte-Carlo numerical simulation of wireline and LWD gamma-ray, density, and neutron logs acquired in vertical, horizontal, and deviated wells.

Future Work: (a) Calculate 3D sensitivity functions for additional commercial configurations of gamma-ray, density, and nuclear wireline and multi-sector LWD measurements.

  • Fast numerical simulation and inversion of nuclear logs.

Future Work: (a) Develop rapid numerical simulations methods for additional commercial wireline and LWD nuclear-tool configurations. (b) Continue testing numerical simulation procedures on field data sets. (c) Expand the capabilities of UTNuPro to calculate the energy spectra of ephithermal and thermal neutron-induced gamma rays of general rock-fluid mixtures.

Combined Interpretation of Resistivity and Nuclear Logs

  • Combined 1D (vertical), 2D (radial and vertical) and dipping-1D inversion of nuclear and resistivity logs in thinly-bedded formations.

Future Work: (a) Extend the 1D combined inversion method to dipping-1D beds thicker than 1ft. (b) Improve the estimation of flow-related petrophysical properties of thinly-laminated clastic rocks. (c) Include magnetic resonance logs in the interpretation of thinly-laminated clastic rocks.

Nuclear Magnetic Resonance Logs

  • New methods for numerical simulation and interpretation of magnetic resonance logs.

Future Work: (a) Develop procedures for the adaptable selection of NMR time-pulsing sequences in response to variable pore and fluid-saturation conditions. (b) Continue to improve the methods for fluid-substitution for the case of T1-T2 and T2-D measurements. (c) Continue to improve the laboratory estimation of saturation-dependent capillary pressure. (d) Summarize best practices for interpretation of NMR logs acquired in spatially heterogeneous rocks.

New Methods for the Petrophysical Interpretation of Well Logs

  • Construction and verification of static and flow-dependent multi-layer petrophysical models.

Future Work: (a) Construct and validate additional static and flow-dependent multi-layer petrophysical models for carbonate formations. (b) Extend the construction and verification exercises to cases of deviated and horizontal wells. (c) Combine and validate static and flow-dependent multi-layer petrophysical models with sonic, magnetic resonance, and formation-tester measurements.

  • Detection, classification, and quantification of rock types/classes.

Future Work: (a) Develop new hierarchical methods for automatic detection, classification, and quantification of rock petrophysical classes based on conventional well logs and core data. (b) Continue to test existing rock classification methods on carbonate and conventional/unconventional clastic sedimentary sequences. (c) Develop automatic methods for rock classification based on supervised and non-supervised machine-learning algorithms augmented with expert petrophysical knowledge.

 Machine-learning and artificial-intelligence methods for the automatic petrophysical interpretation of well logs and core data.

Future Work: (a) Develop machine-learning algorithms for the automatic detection of laminations, dip, azimuth, fractures, and breakouts from borehole images. (b) Develop machine-learning algorithms for the automatic interpretation of well logs based on Bayesian statistical concepts. (d) Develop machine-learning algorithms for the implementation of arbitrary rock-physics models (elastic and mechanical properties) of spatially complex rocks in the calculation of P- and S-wave sonic slownesses.

High-Resolution Assessment of Hydrocarbon-Bearing Shale

  • Core-log assessment of petrophysical, mineral, fluid, elastic and mechanical properties of hydrocarbon-bearing shale.

Future Work: (a) Test the developed diagnostic and quantification methods on additional data sets acquired in different shale plays. (b) Combine neutron-induced spectroscopy measurements with conventional well logs in the assessment of mineral concentrations, total porosity, water saturation, and organic content of hydrocarbon-bearing shale.

Laboratory Studies

  • Measurement, numerical simulation, and interpretation of NMR measurements.

Future Work: (a) Develop specialized gradient-based pulsing sequences to quantify the fluid storage and transport properties of carbonate rocks with multiple dominant pore sizes. (b) Develop methods for the interpretation of multi-frequency magnetic resonance measurements of tight rocks.

  • Development of micro- and nano-fluidics systems for petrophysical assessment of core samples.

Future Work: (a) Design microfluidics experiments for the evaluation of saturation-dependent relative permeability, capillary pressure, and electrical conductivity under various conditions of pore/channel roughness and connectivity. (b) Perform nano-confinement experiments in the presence of controlled electrical double-layer effects.

  • Measurement, numerical simulation, and interpretation of ultrasonic and mechanical measurements of stressed rocks.

Future Work: (a) Investigate and quantify the differences between static and dynamic elastic properties of rocks under variable loading conditions, especially in finely laminated and naturally fractured rocks. (b) Develop an automated system for performing continuous measurements of P- and S-wave velocities of whole core based on angle-dependent, liquid-coupled ultrasonic reflectivity. The system will match laboratory measurements with numerical simulations for both wave-mode detection and attenuation studies of spatially complex rocks.

OP-CSEC-4.         Time-lapse measurements of fluid displacement in heterogeneous rocks via micro-CT imaging.

Future Work: (a) Perform additional experiments of the process of mud-filtrate invasion in grain- and shale-laminated clastic rocks. (b) Perform additional experiments of the process of mud-filtrate invasion in complex carbonates. (c) Continue to improve the experimental system for thin rectangular rock samples to quantify two-phase immiscible flow properties. (d) Conduct additional two-phase flow experiments in thin rectangular rock samples to quantify the effects of grain-size laminations on macroscopic representations of direction- and saturation-dependent relative permeability and capillary pressure.

 

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