A method for evaluating water film is a method for evaluating water film uniformity, and the method includes: a first step of preparing a base material for water film formation having a principal surface for forming a water film thereon; a second step of capturing an image of an object having a pattern in which a plurality of regions having predetermined brightness are disposed in a predetermined area, through the base material for water film formation having a water film formed on the principal surface, to obtain an image for evaluation; and a third step of deriving a water film uniformity index indicating uniformity of the water film based on the area distribution of the regions having predetermined brightness in the image for evaluation.

A solid surface wettability determination method is disclosed. A liquid is sprayed on a surface of an object. A light beam is projected toward the surface, wherein the light beam is reflected by the liquid on the surface to generate a reflected light. The reflected light is received by an optical detector, and the optical detector outputs a determining signal related to a wettability of the surface according to the reflected light. A corresponding signal-angle relation is selected from a database according to type of the liquid and material of the object. The contact angle of the liquid on the surface is obtained by applying the determining signal to the corresponding signal-angle relation.

A measurement system includes a detector configured to detect a contact state of a bubble with respect to a wall, the bubble being included in a fluid that is in contact with a wall, and a controller configured to acquire the state of at least one of the wall, the fluid, and the bubble based on the contact state of the bubble with respect to the wall.

Contact angles of multi-phase mixtures in a porous medium are determined by comparing images generated by flow simulations with a measured image of a fluid flow in the porous medium. A measured image can be compared image element by image element with corresponding locations in the flow simulations. A plurality of flow simulations associated with a corresponding plurality of contact angles is used for the comparison, and a contact angle associated with the greatest number of matches between the measured image and the flow simulation is selected.

A method and system for determining contact angles of porous media, including: in a displacement simulation experiment, injecting a displacement fluid into a actual core sample, and performing computed tomography scanning on the core to determine three-dimensional images at different oil displacing time points; segmenting different phases of the three-dimensional images to obtain segmented three-dimensional images; marking a contact line between different phases according to the segmented three-dimensional images, where the phases are underground fluids or displacement fluids and a rock matrix in the displacement simulation experiment; and determining a contact angle of the porous media at different 3D positions at different time points according to the contact line. The method and system provided can obtain the dynamic changing process of the contact angle at different 3D positions in the core at different displacement time points, reflect the wettability of the real reservoir environment more accurately.

A calibration standard for calibrating a tool for measuring the surface energy of a data storage component is prepared by providing a standardized sized, dimensionally stable bead having a diameter selected from a length of from 1 to 100 m and depositing the bead on a surface of a substrate and adhering the bead to the surface with an adhesive. The calibration standard made by these processes is also contemplated.

Methods of evaluating viscous compositions are disclosed. These methods may be used to evaluate volumetric properties of fluids including peanut butter. The methods may include preparing a surface for testing by leveling and flattening a viscous composition, placing a drop of a liquid on the flattened leveled surface, evaluating the observed contact angle between the drop and the surface, and then comparing the observed contact angle to a reference contact angle.

Methods, systems, and apparatus for analytical wettability assessment of fracturing proppants for improving fluid recovery are disclosed. Embodiments include determining, for a proppant sample, a first value related to an oil-wet index of the proppant sample. Embodiments further include determining, for the proppant sample, a second value related to a water-wet index of the proppant sample. Embodiments further include determining, for the proppant sample based on the first value and the second value, a third value related to a wettability index of the proppant sample. Embodiments further include determining, based on the third value, a wetting characteristic of the proppant sample. Other embodiments may be described.

Techniques for determining a rock wettability alteration include circulating a first brine fluid into a test cell that includes a rock sample and a hydrocarbon fluid disposed on a surface of the rock sample, the first brine fluid having a property at a first value; contacting the rock sample and the hydrocarbon fluid with the first brine fluid; measuring a first contact angle between the rock sample and the hydrocarbon fluid in contact with the first brine fluid; at least partially displacing the first brine fluid with a second brine fluid in the test cell, the second brine fluid having the property at a second value; contacting the rock sample and the hydrocarbon fluid with the second brine fluid; measuring a second contact angle between the rock sample and the hydrocarbon fluid in contact with the second brine fluid; and determining a wettability alteration of the rock sample based on at least one of the measured first or second contact angles.

A method of detecting an organic residue is provided. The method comprises a step of bringing a liquid A into contact with a surface of a base material; a step of measuring the contact angle (i) of a liquid B on the surface with which the liquid A came into contact; a step of heating and drying the base material; a step of measuring the contact angle (ii) of the liquid B on the dried surface; and a step of comparing the contact angle (i) with the contact angle (ii).