Abstract
The development and stimulation of oil and gas fields are inseparable from the experimental analysis of reservoir rocks. Large number of experiments, poor reservoir properties and thin reservoir thickness will lead to insufficient number of cores, which restricts the experimental evaluation effect of cores. Digital rock physics (DRP) can solve these problems well. This paper presents a rapid, simple, and practical method to establish the pore structure and lithology of DRP based on laboratory experiments. First, a core is scanned by computed tomography (CT) scanning technology, and filtering back-projection reconstruction method is used to test the core visualization. Subsequently, three-dimensional median filtering technology is used to eliminate noise signals after scanning, and the maximum interclass variance method is used to segment the rock skeleton and pore. Based on X-ray diffraction technology, the distribution of minerals in the rock core is studied by combining the processed CT scan data. The core pore size distribution is analyzed by the mercury intrusion method, and the core pore size distribution with spatial correlation is constructed by the kriging interpolation method. Based on the analysis of the core particle-size distribution by the screening method, the shape of the rock particle is assumed to be a more practical irregular polyhedron; considering this shape and the mineral distribution, the DRP pore structure and lithology are finally established. The DRP porosity calculated by MATLAB software is 32.4%, and the core porosity measured in a nuclear magnetic resonance experiment is 29.9%; thus, the accuracy of the model is validated. Further, the method of simulating the process of physical and chemical changes by using the digital core is proposed for further study.
Highlights
The development of new wells and the stimulation of production of old wells are inseparable from the experimental analysis of reservoir cores
For an increase or a decrease in rockparticle volume, it is difficult to describe these changes via Digital cores based on laboratory experiments are usually more realistic and accurate than those generated by random algorithms
The computed tomography (CT) scanning technology, X-ray diffraction technology, mercury intrusion experiment, and screening method can well characterize the physical properties of the core
Summary
Ti–Ti+1 mi Mass fraction of a mineral grayTi The gray value is Ti –Ti+1 di The maximum particle size of a mineral in the core, μm dPi The size distribution range of a mineral, μm R Aperture, μm Wetting angle, °. Journal of Petroleum Exploration and Production Technology (2021) 11:2113–2125 n∗ Total number of samples N(j − x) The total number of sample points when the separation distance is j − x x0, y0, z0 Coordinate of descent point xi, yi, zi Neighborhood coordinates of descent point di The sum of the distances from the descent point to each point in the neighborhood, μm d∗ The minimum value of the sum of distances from the descent point to the points in the neighborhood, μm ht Number of intersected blue dotted spheres Vp Volume of rock particles, μm Vrock Total volume of rock, μm
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Journal of Petroleum Exploration and Production Technology
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
