Characterization of Complex Fracture System in Volume Fracturing of Shale Gas Reservoir

After volume fracturing of horizontal wells in shale gas reservoir, an extremely complex fracture system is formed. The space area of the fracture system is the reservoir reconstruction volume of shale gas reservoir. The geometric parameters such as crack length, crack width, crack height, and characteristic parameters such as crack permeability and fracture conductivity proposed for a single crack in conventional fracturing are insufficient to describe and characterize the complex network fracture system after volume fracturing. In this paper, the discrete fracture modeling method is used to establish the volume fracturing network fracture model of horizontal wells in shale gas reservoir by using the random modeling method within the determined reservoir space. The model is random and selective, and can fully provide different forms of volume fracturing fracture expansion, such as conventional fracture morphology, line network model and arbitrarily distributed network fractures. The research results provide a theoretical basis for the development plan and stimulation plan of shale gas reservoir, and have important reference value and significance for other unconventional gas reservoir fracturing.

On Leray's problem in an infinitely long pipe with the Navier-slip boundary condition

The original Leray’s problem concerns the well-posedness of weak solutions to the steady incompressible Navier-Stokes equations in a distorted pipe,which approach the Poiseuille flow subject to the no-slip boundary condition at spatial infinity.In this paper,the same problem with the Navier-slip boundary condition instead of the no-slip boundary condition,is addressed.Due to the complexity of the boundary condition,some new ideas,presented as follows,are introduced to handle the extra difficulties caused by boundary terms.First,the Poiseuille flow in the semi-infinite straight pipe with the Navier-slip boundary condition will be introduced,which will serve as the asymptotic profile of the solution to the generalized Leray’s problem at spatial infinity.Second,a solenoidal vector function defined in the whole pipe,satisfying the Navierslip boundary condition,having the designated flux and equalling the Poiseuille flow at a large distance,will be carefully constructed.This plays an important role in reformulating our problem.Third,the energy estimates depend on a combined L2-estimate of the gradient and the stress tensor of the velocity.

Editorial for Special Issue on Artificial Intelligence for Art

As an innovative engine for digital content generation,AI-generated content(AIGC)has drawn more and more attention from academic fields as well as industries.Specifically in the area of art creation,AI has demonstrated its great potential and gained increasing popularity.People are greatly impressed by AI painting,composing,writing,virtual hosting,fashion,and design.Moreover,AI is also becoming capable of understanding art,evaluating the aesthetic value of art,and protecting the copyright of art as well.AI has not only exhibited creativity to some extent,but also served as an enabling tool to discover the principles underneath creativity and imagination,which are traditional challenges for neuroscience,cognitive science,and psychology.Despite all these promising features of AI for art,we still have to face the many challenges such as the explainability of generative models and the copyright issues of AI art works.

Sensitivity Analysis of Offshore Sandstone Reservoir—A Case Study of an Oilfield in the Western Bohai Sea

X oilfield is located in the Western Bohai Sea. During the water injection development process, the oil well productivity continued to decline. The effect of water injection and oil increase is poor. This time, by analyzing the sensitivity of the reservoir, the damage mode of the reservoir is analyzed, the reasons for the poor water injection effect are obtained, because of strong water sensitivity, medium to strong stress sensitivity, and the corresponding measures and suggestions are put forward, such as greater than 4500 mg/l of the salinity of injected water, timely supplement formation energy. Provide basis for the development of similar oil fields.