The present disclosure describes a method that includes: accessing production logs at a well location of the carbonate reservoir, the production logs comprising data encoding a flow meter profile and a ratio of water and oil (WOR) at each depth of a range of depths; accessing measurements of core samples extracted from each depth within the range of depths; based on the measurements of core samples, determining a relationship of permeability and porosity at each depth within the range of depths; based on the production logs, analyzing the WOR to determine a derivative WOR′ (dWOR/dt) at each depth within the range of depths; and characterizing at least one productive zone at the well location based on a combination of the WOR, the WOR′, the flow meter profile, and the relationship of permeability and porosity at each depth within the range of depths.

Provided herein are various embodiments of determining a cation exchange capacity of a rock sample. One embodiment of a method of determining a cation exchange capacity of a rock sample comprises equilibrating the rock sample to a relative humidity, performing a dielectric permittivity measurement on the rock sample at the relative humidity, and determining a cation exchange capacity of the rock sample based on the dielectric permittivity measurement. One embodiment of a method of determining a cation exchange capacity of a rock sample comprises receiving a dielectric permittivity measurement on the rock sample, and determining a cation exchange capacity for the rock sample based on the dielectric permittivity measurement of the rock sample and a relationship between cation exchange capacity and dielectric permittivity measurements for mineral mixtures corresponding to a range of cation exchange capacity values.

Provided herein are various embodiments of determining a cation exchange capacity of a rock sample. One embodiment of a method of determining a cation exchange capacity of a rock sample comprises equilibrating the rock sample to a relative humidity, performing a dielectric permittivity measurement on the rock sample at the relative humidity, and determining a cation exchange capacity of the rock sample based on the dielectric permittivity measurement. One embodiment of a method of determining a cation exchange capacity of a rock sample comprises receiving a dielectric permittivity measurement on the rock sample, and determining a cation exchange capacity for the rock sample based on the dielectric permittivity measurement of the rock sample and a relationship between cation exchange capacity and dielectric permittivity measurements for mineral mixtures corresponding to a range of cation exchange capacity values.

Methods for determining reservoir characteristics of a well can include receiving a first core from the well; performing an experiment to determine the wave velocity associated with a first direction of the first core, the experiment including: transmitting an ultrasonic wave through the first core in the first direction; receiving the transmitted ultrasonic wave; and determining a directional wave velocity of the first core based on the transmitted ultrasonic wave and the received transmitted ultrasonic wave, wherein the directional wave velocity represents a wave velocity along the first direction; rotating the first core about a longitudinal axis of the first core; and performing the experiment along a second direction of the first core.

Methods for determining reservoir characteristics of a well can include receiving a first core from the well; performing an experiment to determine the wave velocity associated with a first direction of the first core, the experiment including: transmitting an ultrasonic wave through the first core in the first direction; receiving the transmitted ultrasonic wave; and determining a directional wave velocity of the first core based on the transmitted ultrasonic wave and the received transmitted ultrasonic wave, wherein the directional wave velocity represents a wave velocity along the first direction; rotating the first core about a longitudinal axis of the first core; and performing the experiment along a second direction of the first core.

In a method for determination of properties of cuttings from rock drilling the cuttings are crushed between at least two rollers, at least one roller being driven by a motor. A mechanic specific energy of the cuttings is determined by measuring the energy applied by the motor.

In a method for determination of properties of cuttings from rock drilling the cuttings are crushed between at least two rollers, at least one roller being driven by a motor. A mechanic specific energy of the cuttings is determined by measuring the energy applied by the motor.

The method includes gathering field data of a formation, preparing samples of brine consistent with the composition of the formation brine and the injection brine, dead crude oil, and live crude oil, and characterizing the properties of crude oil samples. The method includes preparing samples of reservoir rock and characterizing the properties of the rock samples of the formation. The method includes measuring the contact angle of surfactant/formation brine/formation rock/formation crude oil samples at ambient and reservoir conditions and measuring the interfacial tension of the sample. The method includes characterizing the HLD properties of each surfactant. In addition, the method includes performing formulation targeting HLD=0 for a mixture of surfactants, performing laboratory evaluation of the HLD=0 formulation of the mixture of the surfactants to obtain values of oil recovery number, and testing the HLD=0 formulation of the mixture of the first and second selected surfactants in the formation.

The method includes gathering field data of a formation, preparing samples of brine consistent with the composition of the formation brine and the injection brine, dead crude oil, and live crude oil, and characterizing the properties of crude oil samples. The method includes preparing samples of reservoir rock and characterizing the properties of the rock samples of the formation. The method includes measuring the contact angle of surfactant/formation brine/formation rock/formation crude oil samples at ambient and reservoir conditions and measuring the interfacial tension of the sample. The method includes characterizing the HLD properties of each surfactant. In addition, the method includes performing formulation targeting HLD=0 for a mixture of surfactants, performing laboratory evaluation of the HLD=0 formulation of the mixture of the surfactants to obtain values of oil recovery number, and testing the HLD=0 formulation of the mixture of the first and second selected surfactants in the formation.

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.