US-12625296-B2 - System and method for enhancing petrophysical characterization of porous media

US12625296B2US 12625296 B2US12625296 B2US 12625296B2US-12625296-B2

Abstract

A system for analysis of a porous formation is disclosed. Such a system can provide electrical signals for one or more of the porous formation or a representation of the porous formation; can determine, using the electrical signals, permittivity and conductivity measures for the porous formation or the representation of the porous formation; and can model the permittivity and conductivity measures to generate a first estimation model associated with pore features for the porous formation, so that a downhole rock formation can be evaluated for pore connectivity, permeability, and Archie's texture parameters using estimation models.

Inventors

Guodong Jin
Ryan Antle
Brian Reeves
Jeremy Vandam

Assignees

BAKER HUGHES OILFIELD OPERATIONS LLC

Dates

Publication Date: 20260512
Application Date: 20220614

Claims (20)

1 . A method for a wellbore operation, the method comprising: determining dielectric property values for a plurality of porous samples, the porous samples being a representation or artificially-produced porous samples; obtaining structural property values for the plurality of porous samples; generating a model, using a processor, for petrophysical property values of the plurality of porous samples by relating the dielectric property values and the structural property values; measuring, in a wellbore and using a dielectric sensor, a rock formation dielectric property value of a downhole rock formation in the wellbore; determining, using the processor, a rock formation petrophysical property value for the downhole rock formation using the model and the measured rock formation dielectric property value; and performing the wellbore operation based at least in part on the rock formation petrophysical property value; wherein the wellbore operation comprises one or more of changing a well trajectory, controlling a steering device, or sending a downlink.
2 . The method of claim 1 , wherein the dielectric property values is one of a permittivity value, a conductivity value, or a resistivity value.
3 . The method of claim 1 , wherein the structural property values is a measure of a pore connectivity.
4 . The method of claim 3 , further comprising: determining the measure of the pore connectivity using one of a 2D or a 3D representation of the plurality of porous samples.
5 . The method of claim 1 , further comprising: determining the dielectric property values for the plurality of porous samples using multiple frequencies to provide frequency-dependent dielectric property values for individual ones of the dielectric property values for the plurality of porous samples.
6 . The method of claim 5 , wherein the multiple frequencies are within a range 10 MHz to 2 GHz.
7 . The method of claim 5 , further comprising: generating the model for the petrophysical property values from a combination of estimation models, wherein a first one of the estimation models relates the frequency-dependent dielectric property values to the multiple frequencies.
8 . The method of claim 7 , further comprising: selecting a frequency of the multiple frequencies; determining, for individual ones of the plurality of porous samples, an individual one of the frequency-dependent dielectric property values at the selected frequency using the first one of the estimation models; and generating a second one of the estimation models based in part on relating the individual one of the frequency-dependent dielectric property values to the structural property values for the plurality of porous samples.
9 . The method of claim 8 , wherein the structural property values comprises a measure of a pore connectivity.
10 . The method of claim 8 , further comprising: determining first estimation model parameter values to enable a fit for the frequency-dependent dielectric property values of the first one of the estimation models; and generating the second one of the estimation models based in part on relating the first estimation model parameters values to the structural property values.
11 . The method of claim 8 , further comprising: generating a third one of the estimation models based in part on relating the structural property values to the petrophysical property values of the plurality of porous samples.
12 . The method of claim 1 , further comprising: determining the dielectric property values using one or more simulations or one or more of multi-frequency dielectric measurements.
13 . The method of claim 1 , further comprising: generating a plurality of estimation models to contribute to the model, individual ones of the plurality of estimation models comprising one or more of the structural property values and providing a model parameter to be used to determine the rock formation petrophysical property value.
14 . The method of claim 13 , further comprising: storing the plurality of estimation models in a non-volatile memory, wherein determining the rock formation petrophysical property value includes selecting at least one of the plurality of estimation models from the non-volatile memory to be used with the measured rock formation dielectric property value.
15 . The method of claim 1 , wherein the rock formation petrophysical property value is an Archie parameter value.
16 . The method of claim 1 , wherein the rock formation petrophysical property value is a permeability value.
17 . The method of claim 1 , further comprising: generating the model by obtaining nuclear magnetic resonance (NMR) parameter values, wherein the NMR parameter values include at least values for a total porosity and for partial porosities.
18 . The method of claim 1 , further comprising: generating the model based in part on curve fitting, wherein the curve fitting includes one of a polynomial curve, an exponential curve, a logarithmic curve, a logistic curve, and a power curve for the relating of the dielectric property values and the structural property values.
19 . The method of claim 1 , further comprising: determining the rock formation petrophysical property value using a processor in a bottom hole assembly (BHA) that is in the downhole rock formation.
20 . A system for a wellbore operation, the system comprising: a dielectric sensor used in a wellbore and configured to measure a rock formation dielectric property value of a downhole rock formation of the wellbore; and at least one processor and memory comprising instructions that when executed by the at least one processor cause the system to: determine dielectric property values for a plurality of porous samples, the porous samples being a representation or artificially-produced porous samples; obtain structural property values for the plurality of porous samples; generate a model for petrophysical property values of the plurality of porous samples by relating the dielectric property values and the structural property values; and determine a rock formation petrophysical property value for the downhole rock formation using the model and the measured rock formation dielectric property value, wherein the rock formation petrophysical property value is used at least in part to perform the wellbore operation; wherein the wellbore operation comprises one or more of changing a well trajectory, controlling a steering device, or sending a downlink.

Description

CROSS-REFERENCES TO RELATED APPLICATIONS This application is a related to and claims the benefit of priority from U.S. Provisional Application No. 63/210,808, titled SYSTEM AND METHOD FOR ENHANCING PETROPHYSICAL CHARACTERIZATION OF POROUS MEDIA, and filed on Jun. 15, 2021, the entire disclosure of which is hereby incorporated by reference herein for all intents and purposes. BACKGROUND 1. Field of Invention The disclosure herein relates in general to equipment used in the natural gas industry, and in particular, to analysis of pore connectivity, permeability, and Archie's texture parameters of porous formations using permittivity and conductivity from electrical signals supported by other subsystems. 2. Description of the Prior Art A drilling well is a structure formed in subterranean or underwater geologic structures, or layers. Such subterranean or underwater geologic structures or layers incorporate pressure that may be further enhanced by supplementing formation fluids (such as liquids, gasses or a combination) into a drill site or a well site (such as a wellbore). Wireline logging tools may be used with capability to evaluate Nuclear magnetic resonance (NMR) measurements used in porous formation to provide a pore size distribution of a porous formation. However, it may not provide a degree of pore connectivity that may be useful to understand how individual pores are connected to each other. When pores are isolated from a network of void spaces in a porous formation, or connected to a network via narrow throats, they contribute very little to permeability, but can still contribute to a total porosity. SUMMARY In at least one embodiment, a system for analysis of a porous formation is disclosed. An electrical subsystem can provide electrical signals for one or more of the porous formation or a representation of the porous formation. At least one processor can execute instructions from a memory to cause the system to perform functions, including to determine, using the electrical signals, permittivity and conductivity measures for the porous formation or the representation of the porous formation. Modelling is enabled, using the permittivity and conductivity measures to generate a first estimation model associated with pore features for the porous formation, so that the first estimation model can be used to estimate or predict a first petrophysical characteristic of a downhole rock formation. In at least one embodiment, a method for analysis of a porous formation is also disclosed. The method includes providing, using an electrical subsystem, electrical signals for one or more of the porous formation or a representation of the porous formation. The method includes executing, using at least one processor, instructions from a memory to cause the at least one processor to perform functions. A function includes determining, using the electrical signals, permittivity and conductivity measures for the porous formation or the representation of the porous formation. A further function includes modelling the permittivity and conductivity measures to generate a first estimation model associated with pore features for the porous formation, so that the first estimation model can be used to estimate or predict a first petrophysical characteristic of a downhole rock formation. In at least one embodiment, a method and a system for a wellbore operation is disclosed. In at least one embodiment, such a method may be performed in part as functions in a system including at least one processor and memory comprising instructions that when executed by the at least one processor cause the system to perform the functions. Such steps of a method or such functions include determining dielectric property values for a plurality of porous samples and obtaining structural property values for the plurality of porous samples. A further step or function is for generating a model for petrophysical property values of the plurality of porous samples by relating the dielectric property values and the structural property values. Furthermore, a step or function herein includes measuring, using a dielectric sensor, a rock formation dielectric property value of a downhole rock formation. A step or function for determining a rock formation petrophysical property value is performed, for the downhole rock formation, using the model and the measured rock formation dielectric property value. The method or function supports or includes performing the wellbore operation based at least in part on the rock formation petrophysical property value. BRIEF DESCRIPTION OF THE DRAWINGS Various embodiments in accordance with the present disclosure will be described with reference to the drawings, in which: FIG. 1 illustrates an example environment subject to improvements of at least one embodiment herein; FIG. 2 illustrates a downhole tool that can include a wireline system for analysis of a downhole rock formation that is partly in the downhole environment and p