A system for analysis of isolated and connected porosities of a porous formation using permittivity is disclosed. An electrical subsystem can provide electrical signals for one or more of the porous formation or a representation of the porous formation; and the system can determine one or more of a rate of permittivity change (RPC) or permittivity ratio (PR) from a first estimation model that relates permittivity measurements and frequencies that are associated with the electrical signals, so that the system can generate a second estimation model using one or more of the RPC or the PR, associated with the isolated and connected porosities, where the second estimation model can be used with a total porosity of the porous formation to estimate or predict an isolated porosity and a connected porosity of a production porous formation.

A porosity model of a core sample obtained from a subterranean formation is determined. The porosity model includes a macroporosity group and a microporosity group. A nuclear magnetic resonance (NMR) measurement is performed to obtain an NMR T.sub.2 distribution of the core sample at 100% water saturation. A desaturation step is performed on the core sample. An NMR measurement is performed for the desaturation step to obtain an NMR T.sub.2 distribution of the core sample. A resistivity index of the subterranean formation is determined at least based on the porosity model and each of the NMR T.sub.2 distributions.

A method, a device and a medium for acquiring logging parameters are provided, wherein the logging parameters include gas-bearing porosities, and the method includes: acquiring a two-dimensional nuclear magnetic logging analysis graph; determining a gas-bearing region from the two-dimensional nuclear magnetic logging analysis graph; and summing contour values of the gas-bearing region as a gas-bearing porosity. The device for acquiring logging parameters includes a processor and a computer readable storage medium, wherein instructions are stored in the computer readable storage medium, and the processor executes the instructions to perform the foregoing method for acquiring logging parameters. The medium for acquiring logging parameters stores computer executable instructions, which are used for executing the foregoing method for acquiring logging parameters.

A method, a device and a medium for acquiring logging parameters are provided, wherein the logging parameters include gas-bearing porosities, and the method includes: acquiring a two-dimensional nuclear magnetic logging analysis graph; determining a gas-bearing region from the two-dimensional nuclear magnetic logging analysis graph; and summing contour values of the gas-bearing region as a gas-bearing porosity. The device for acquiring logging parameters includes a processor and a computer readable storage medium, wherein instructions are stored in the computer readable storage medium, and the processor executes the instructions to perform the foregoing method for acquiring logging parameters. The medium for acquiring logging parameters stores computer executable instructions, which are used for executing the foregoing method for acquiring logging parameters.

A method of estimating a wettability characteristic of a rock and fluid system includes acquiring a sample of the rock material, performing a first nuclear magnetic resonance (NMR) measurement of the sample when the sample is in a full water saturation condition, and measuring a first T2 distribution, performing a second NMR measurement of the sample when the sample is in a second partial saturation condition, and measuring a second T2 distribution. The method also includes separating a hydrocarbon component of the second T2 distribution from a water component of the second T2 distribution, applying a fluid substitution model to the water component of the second T2 distribution to generate a computed T2 distribution, and calculating a wettability index (WI) based on a difference between the first T2 distribution and the computed T2 distribution.

A method of estimating a wettability characteristic of a rock and fluid system includes acquiring a sample of the rock material, performing a first nuclear magnetic resonance (NMR) measurement of the sample when the sample is in a full water saturation condition, and measuring a first T2 distribution, performing a second NMR measurement of the sample when the sample is in a second partial saturation condition, and measuring a second T2 distribution. The method also includes separating a hydrocarbon component of the second T2 distribution from a water component of the second T2 distribution, applying a fluid substitution model to the water component of the second T2 distribution to generate a computed T2 distribution, and calculating a wettability index (WI) based on a difference between the first T2 distribution and the computed T2 distribution.

Methods and systems are provided that combine NMR and IR spectroscopy measurements on a rock sample to determine data representing at least one property of the rock sample. In one embodiment, cuttings can be split into first and second lots. Results of an NMR measurement performed on the first lot of cuttings without cleaning can be analyzed to determine pore volume of the cuttings. Results of an IR spectroscopy measurement performed on the second lot of cuttings after solvent cleaning can be analyzed to determine matrix density of the cuttings. Porosity can be determined from the pore volume and matrix density of the cuttings. In another embodiment, combined NMR and IR spectroscopy measurements can be performed on an unprepared rock sample (without solvent cleaning) to characterize properties of kerogen in the rock sample and porosity. In another aspect, a method is provided that employs multi-nucleic NMR measurements to determine porosity.

Methods and systems are provided that combine NMR and IR spectroscopy measurements on a rock sample to determine data representing at least one property of the rock sample. In one embodiment, cuttings can be split into first and second lots. Results of an NMR measurement performed on the first lot of cuttings without cleaning can be analyzed to determine pore volume of the cuttings. Results of an IR spectroscopy measurement performed on the second lot of cuttings after solvent cleaning can be analyzed to determine matrix density of the cuttings. Porosity can be determined from the pore volume and matrix density of the cuttings. In another embodiment, combined NMR and IR spectroscopy measurements can be performed on an unprepared rock sample (without solvent cleaning) to characterize properties of kerogen in the rock sample and porosity. In another aspect, a method is provided that employs multi-nucleic NMR measurements to determine porosity.

Certain aspects of the present disclosure provide methods and apparatus for closed-loop control of a system using one or more electron paramagnetic resonance (EPR) sensors located on-site. With such EPR sensors, a change can be applied to the system, the EPR sensors can measure the effect(s) of the change, and then adjustments can be made in real-time. This feedback process may be repeated continuously to control the system.

Certain aspects of the present disclosure provide methods and apparatus for closed-loop control of a system using one or more electron paramagnetic resonance (EPR) sensors located on-site. With such EPR sensors, a change can be applied to the system, the EPR sensors can measure the effect(s) of the change, and then adjustments can be made in real-time. This feedback process may be repeated continuously to control the system.