PUMA publications for /user/simtech_testFri Nov 08 09:56:54 CET 2024janTest Post Deletion Copy Version 312024pn1 curated test Fri Nov 08 09:56:26 CET 2024my test journalTest Post Deletion Copy Version 212024pn1 test my test abstractTue Oct 15 13:46:10 CEST 2024unknown my updated test journaljan23-4Test Post Deletion Copy Version 112024pn1 curated test my updated test abstractTue Oct 15 13:45:12 CEST 2024my test journaljan23-4Test Post Deletion Original Copy12024pn1 curated Tue Oct 15 13:41:34 CEST 2024unknown my test journal23-4Test Post Deletion Original2024pn1 curated Tue Aug 27 19:02:57 CEST 2024Transp. Porous MediaMarginal Percentile Intervals in Bayesian Inference are Overconfident Duplicate2024PN1 curated Add My own Abstract Tue Aug 27 18:49:04 CEST 2024My test article2024PN1 curated Wed Aug 07 08:33:40 CEST 2024Test Publication2024PN1-1 curated Tue Aug 06 18:01:04 CEST 2024Unknown Journal NameMy test article2024PN1 curated Tue Aug 06 16:08:45 CEST 2024Transport in Porous MediaJanuary12My updated publication12024includesSelectedJournal inReview My abstractFri Jun 07 12:48:08 CEST 2024Transp. Porous MediaMarginal Percentile Intervals in Bayesian Inference are Overconfident2024myown selected curated Add My own Abstract Thu May 16 16:08:39 CEST 2024Advances in Water Resources103716Upscaled equations for two-phase flow in highly heterogeneous porous media: Varying permeability and porosity1452020updated In this article we consider a two-phase flow model in a highly heterogeneous porous column. The porous column consists of homogeneous blocks, where the porosity and permeability vary from one block to the other. The flow direction is perpendicular to the layering of the porous column, and hence can be approximated by one-dimensional model equations. The periodic change in porosity and absolute permeability enforce the fluid to be trapped at the interface between the blocks, leading to a highly varying saturation. In order to capture the effective behavior, upscaled equations for the average saturation are derived via homogenization. This technique relies on a notion of periodicity and allows averaging over any number of blocks that may have any internal distributions of the rock parameters. Moreover, the present article also derives effective equations for randomly distributed layers of different porosity and absolute permeability. Numerical experiments are performed which show good agreement between the averaged solutions of the original micro-scale equations and the solutions of the upscaled equations, also in the case of randomly distributed layers. In particular these numerical experiments show how the internal distribution of the permeability and porosity affect the effective behavior of the flow.Thu May 16 16:06:19 CEST 2024Computational Geosciences31445--1461Non-classical flow modeling of spontaneous imbibition in spatially heterogeneous reservoirs242020includesSelectedJournal selected curated In this study, imbibition process is investigated in heterogeneous hydrocarbon reservoir using the non-classical (effective viscous finger) model equations proposed by Luo et al. (SPE Res. Eval. Engineering, 20(4), 1–16 2017). Counter-current spontaneous imbibition is analyzed in different heterogeneous porous media. The heterogeneity is mainly due to the spatial variation of the porosity and absolute permeability. The proposed mathematical model is solved considering the Implicit Pressure Explicit Saturation Scheme (IMPES) via finite difference method (FDM). Effect of the viscosity ratio, growth rate exponent of the fingering function, and the maximum fingering cross section on the normalized water saturation are analyzed. The present model is verified in the limiting case of classical model equations in homogeneous medium. It is noted that rate and extent of the counter-current imbibition are significantly controlled by the distribution of heterogeneous parameters like porosity and absolute permeability of the reservoir.Thu May 16 16:00:16 CEST 2024Transport in Porous Media3947--968Modeling of Co-current Spontaneous Imbibition Oil Recovery from Partially Covered Homogeneous Hydrocarbon Reservoir1302019includesSelectedJournal inReview In this paper, an approximate integral equation solution for a horizontal, unsteady flow of two viscous incompressible fluids is derived. Wettability variation of the porous medium is also considered in the present study. The non-wetting phase recovery fraction is obtained in terms of dimensionless time for 1D model from the derived solution. The derived approximate recovery fraction has been compared with the existing experimental data and empirical correlations for spontaneous imbibition from water-wet medium. It is observed that the normalized water saturation profiles show sharp gradients indicating some instability of the water front. Hence, a linear stability analysis is developed to study viscous instability of the co-current spontaneous imbibition. Viscous instability phenomenon for a two-phase oil–water system is also discussed. The corresponding instability number related to co-current imbibition recovery is estimated. The present study clearly spells out the effect of the instability number on the recovery process and estimates a critical instability number for co-current spontaneous imbibition.Thu May 16 15:59:42 CEST 2024European Journal of Mechanics - B/Fluids81-97Mathematical modeling of co-current spontaneous imbibition in heterogeneous porous medium762019curated Fractured carbonate reservoirs are principal crude oil and natural gas resources. These reservoirs are composed of matrix block with interconnected network of fractures. Oil or gas recovery from such low porous and low permeable reservoirs is important because a large amount of such hydrocarbon fluids are trapped inside those reservoir formulations. Water-flooding or more specifically spontaneous imbibition is one of the most effective recovery mechanisms to increase the production from fractured reservoirs. However, the performance of water-flooding mainly depends on the wettability of the reservoirs. In co-current imbibition, wetting phase displaces the non-wetting phase in such a way that the non-wetting phase moves in the same direction of the wetting phase. Hence the corresponding mathematical model requires a total flux condition. This study deals with the mathematical modeling of co-current spontaneous imbibition from heterogeneous porous reservoirs. The resulting governing equations are highly non-linear in nature. We solve these equations numerically and show that the co-current imbibition recovery is very much sensitive to the viscosity ratio, porosity variation models and the wettability of the reservoir. The impact of the viscosity ratio on the water saturation gradient and the end point mobility ratio is also analyzed. In addition, the variations in the heterogeneity and wettability of the medium and the corresponding influence on the sweeping efficiency of the co-current imbibition is investigated.Thu May 16 15:39:00 CEST 2024Physical Review Aapr4Device-independent quantum private query952017myown curated updated includesSelectedJournal Thu May 16 15:07:44 CEST 2024Quantum Information & Computation202011 & 12957-968(t, n) Threshold d-level quantum secret sharing based on quantum Fourier transformation202020myown inReview Wed May 15 13:43:31 CEST 2024Physical Review A4042344Device-independent quantum private query952017myown curated updated includesSelectedJournal In quantum private query (QPQ), a client obtains values corresponding to his or her query only, and nothing else from the server, and the server does not get any information about the queries. V. Giovannetti et al. [Phys. Rev. Lett. 100, 230502 (2008)] gave the first QPQ protocol and since then quite a few variants and extensions have been proposed. However, none of the existing protocols are device independent; i.e., all of them assume implicitly that the entangled states supplied to the client and the server are of a certain form. In this work, we exploit the idea of a local CHSH game and connect it with the scheme of Y. G. Yang et al. [Quantum Info. Process. 13, 805 (2014)] to present the concept of a device-independent QPQ protocol.