The present disclosure provides a method for recovering a porosity evolution process of sequence stratigraphy of carbonate rocks. The method comprises: a step of establishing a sequence stratigraphic framework of carbonate rocks; a step of dividing diagenetic stages; a step of simulating diagenesis and porosity evolution with increasing reservoir thickness and continuous superposition of multiple reservoirs during cyclic rise and fall of sea level to obtain a simulation result; and a step of calculating the porosity evolution in space over time by using the simulation result as initial values for simulation of diagenetic evolution process and simulating in stages and continuity the multi-stage diagenetic evolution process that the carbonate rock strata undergo after sediment based on the divided diagenetic stages. Compared with the traditional recovery of single reservoir porosity with time evolution, the method fully considers the superposition effect of multiple upper reservoirs in the process of reservoir sedimentary-diagenesis.

A high-temperature and high-pressure microscopic visual flowing device and an experimental method are provided by the present disclosure, comprising a seepage simulation system, a micro-displacement and metering system connected to the seepage simulation system, and an image acquisition and analysis system; the seepage simulation system consists of a visual high-temperature and high-pressure kettle, a microscopic core model placed in the visual high-temperature and high-pressure kettle, and glass carriers arranged above and below the microscopic core model; the glass carriers are provided with sealing rubber sleeves, and the visual high-temperature and high-pressure kettle is provided with an annular heating jacket; an outlet of the microscopic core model is provided with a microflow channel which is connected to the micro-displacement and metering system through a pipe, effectively reducing the metering error caused by the dead volume of the pipe.

A method and system is provided that analyzes flow characteristics of return fluid that flows to a surface-located facility during well operations (such as plug mill-out or cleanout/workover operations) in order to characterize local formation properties of the formation. The method and system can be used to characterize a hydraulically-fractured hydrocarbon-bearing formation that is traversed by a well having a number of intervals that are hydraulically isolated from one another by corresponding plugs.

A method may comprise obtaining a formation sample, scanning the formation sample to form a data packet, loading the data packet on an information handling machine, performing a digital porous plate experiment with the data packet, and determining geometry of a pore throat in the formation sample. A system may comprise a computer tomographic machine configured to scan a formation sample and create a data packet from the scan and an information handling system. The information handling system may be configured to configured to perform a digital porous plate experiment with the data packet and determine geometry of a pore throat in the formation sample.

In some aspects, a device may receive measurement data associated with a measurement subject. The device may determine an adsorption isotherm for the measurement subject based on the measurement data. The device may determine a thermodynamic adsorption capacity of the measurement subject based on the adsorption isotherm. The device may determine a surface area value associated with the measurement subject based on the thermodynamic adsorption capacity. The device may provide an output based on the adsorption capacity or the surface area value associated with the measurement subject.

A method for determining pore size distribution of rocks is provided. Capillary pressure measurements on rock cores are analyzed to determine a pore size distribution, with smaller pores requiring greater capillary pressure to relinquish contained fluid. Large pores with rough surfaces introduce inaccuracies in determining the pore size distribution. Embodiments of the invention correct the rough surface induced inaccuracies by measuring the shift in NMR T2 distribution from full saturation to the current state of desaturation and subtracting the T2 contributions in the desaturated state that have smaller T2 values (i.e., smaller transverse relaxation time) than the smallest T2 values (i.e., shortest transverse relaxation time) in the saturated distribution.

Provided is a method of calculating a tortuous hydraulic diameter of a porous medium for laminar flow and turbulent flow considering a geometric feature and a friction loss feature. A method of calculating a tortuous hydraulic diameter of a porous medium, according to an embodiment of the present invention, includes providing porosity and a specific surface area of a porous medium, calculating a hydraulic diameter of the porous medium by using the porosity and the specific surface area, calculating tortuosity of the porous medium, and calculating a tortuous hydraulic diameter corresponding to a function of tortuosity, by using the hydraulic diameter and the tortuosity of the porous medium.

A system for measuring a porosity of a gravel pack in a wellbore includes a transmitting acoustic transducer attached to a sand screen and configured to transmit an acoustic signal. The system further includes multiple acoustic transducers attached to the sand screen and configured to receive the acoustic signal through the gravel pack. The system also includes a control device configured to receive electrical signals from the multiple acoustic transducers and determine the porosity of the gravel pack around the sand screen based on at least the electrical signals. The electrical signals are generated from the acoustic signal received by the multiple acoustic transducers.

The system includes a gas tank. A reference volume is fluidly coupled to the gas tank. A coreholder fluidly is coupled to the reference volume. A sample is disposed in the coreholder. A fluid pump is fluidly coupled to the coreholder. A first pressure transducer is fluidly coupled between the fluid pump and the coreholder. The first pressure transducer measures a confining pressure. A second pressure transducer is fluidly coupled to the coreholder. The second pressure transducer measures upstream pressure within the coreholder.

To separate porosity from surface roughness, length scales for pore size and surface roughness are identified. These length scales are determined from surface roughness measurements and confirmed via NMR pore body calculations and pore size capillary pressure measurements. A filter removes pore contribution to surface roughness measurements and delivers intrinsic surface roughness. Additional filters and methods determine the minimum magnification on which to base surface roughness calculation, based on size of the field of view and where measured surface roughness approaches intrinsic surface roughness as magnification increases but larger magnification increase sampling time and difficulty. Sample irregularities, such as saw marks, are also filtered out or determined to be too large to remove via filter and another area of measurement is located. With the pore corrected quantification of surface roughness, surface relaxivity and pore distribution can be calculated with greater accuracy.