Application of Digital Rock Analysis for Evaluation of Gas-Condensate Transport

2021 ◽  
Author(s):  
Oleg Dinariev ◽  
Nikolay Evseev
Keyword(s):  
Density Functional ◽  
Development Planning ◽  
Gas Condensate ◽  
Computational Method ◽  
Kinetic Properties ◽  
Pore Scale ◽  
Digital Rock ◽  
Compositional Model ◽  
Rock Analysis ◽  
Phase Mobility

Abstract The computational method for gas-condensate phase permeabilities is presented using digital rock analysis. The proposed method combines: a) construction of high-resolution tomographic images of the pore space; b) development of compositional model of a gas-condensate mixture at pore-scale including rheology, fluid-fluid and fluid-rock interfacial tension coefficients, and thermodynamic and kinetic properties of fluid phases; c) 3D pore-scale modeling of multiphase transport and interfacial chemical component exchange using the density functional hydrodynamics numerical simulator. This digital rock analysis workflow is applied to the gas-condensate transport at pore-scale. The numerical simulations are carried out using the 3D digital rock model constructed by X-ray microCT imaging of the rock pore structure. By specifying different gas and condensate fractions and injection rates it has been possible to obtain computationally 3D saturation distribution fields and the phase permeabilities. The results of 3D density functional hydrodynamic simulations provide the comprehensive description of gas-condensate mixture at pore-scale including hydrodynamic desaturation effects and phase transition kinetic phenomena. It is demonstrated that condensate distribution in pores, phase mobility thresholds and phase permeabilities are dependent on wettability properties and flow rates. It is shown that condensate composition in individual pores is also dynamically dependent on flow regimes. These results can be used in field development planning for the improved evaluation of condensate banking in the vicinity of production wells and condensate losses in the reservoir.

A Case History for an Integrated Asset Model with Fluid Delumping for a Complex Gas Condensate Field

2021 ◽  
Author(s):  
Mohamed Ibrahim Mohamed ◽  
Ahmed Mahmoud El-Menoufi ◽  
Eman Abed Ezz El-Regal ◽  
Ahmed Mohamed Ali ◽  
Khaled Mohamed Mansour ◽  
...  
Keyword(s):  
Development Planning ◽  
Production Optimization ◽  
Operating Conditions ◽  
Gas Condensate ◽  
Western Desert ◽  
Design Parameters ◽  
Compositional Model ◽  
Compositional Approach ◽  
Process Plant ◽  
Black Oil

Abstract Field development planning of gas condensate fields using numerical simulation has many aspects to consider that may lead to a significant impact on production optimization. An important aspect is to account for the effects of network constraints and process plant operating conditions through an integrated asset model. This model should honor proper representation of the fluid within the reservoir, through the wells and up to the network and facility. Obaiyed is one of the biggest onshore gas field in Egypt, it is a highly heterogeneous gas condensate field located in the western desert of Egypt with more than 100 wells. Three initial condensate gas ratios are existing based on early PVT samples and production testing. The initial CGR values are as following;160, 115 and 42 STB/MMSCF. With continuous pressure depletion, the produced hydrocarbon composition stream changes, causing a deviation between the design parameters and the operating parameters of the equipment within the process plant, resulting in a decrease in the recovery of liquid condensate. Therefore, the facility engineers demand a dynamic update of a detailed composition stream to optimize the system and achieve greater economic value. The best way to obtain this compositional stream is by using a fully compositional integrated asset model. Utilizing a fully compositional model in Obaiyed is challenging, computationally expensive, and impractical, especially during the history match of the reservoir numerical model. In this paper, a case study for Obaiyed field is presented in which we used an alternative integrated asset modeling approach comprising a modified black-oil (MBO) that results in significant timesaving in the full-field reservoir simulation model. We then used a proper de-lumping scheme to convert the modified black oil tables into as many components as required by the surface network and process plant facility. The results of proposed approach are compared with a fully compositional approach for validity check. The results clearly identified the system bottlenecks. The model enables the facility engineers to keep the conditions of the surface facility within the optimized operating envelope throughout the field's lifetime and will be used to propose new locations and optimize the tie-in location of future wells in addition to providing flow assurance indications throughout the field's life and under different network configurations.

A Combined Molecular Docking and Density Functional Theory Nuclear Magnetic Resonance Study of Trans-Dehydrocrotonin Interacting with COVID-19 Main Protease and Severe Acute Respiratory Syndrome Coronavirus 2 3C-Like Protease

2021 ◽  
Vol 21 (11) ◽  
pp. 5399-5407
Author(s):  
Evani Ferreira Cardoso ◽  
Thaís Forest Giacomello ◽  
Leandro Leal Rocha de Oliveira ◽  
Tiago Arouche da Silva ◽  
Antonio Maia de Jesus Chaves Neto ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Natural Products ◽  
Molecular Docking ◽  
Magnetic Resonance ◽  
Neutralizing Antibodies ◽  
Density Functional ◽  
Computational Method ◽  
Spike Protein ◽  
Experimental Result ◽  
Nuclear Magnetic

For the development of drugs that treat SARS-CoV-2, the fastest way is to find potential molecules from drugs already on the market. Unfortunately, there is currently no specific drug or treatment for COVID-19. Among all structural proteins in SARS-CoV, the spike protein is the main antigenic component responsible for inducing host immune responses, neutralizing antibodies, and/or protecting immunity against virus infection. Molecular docking is a technique used to predict whether a molecule will bind to another. It is usually a protein to another or a protein to a binding compound. Natural products are potential binders in several studies involving coronavirus. The structure of the ligand plays a fundamental role in its biological properties. The nuclear magnetic resonance technique is one of the most powerful tools for the structural determination of ligands from the origin of natural products. Nowadays, molecular modeling is an important accessory tool to experimentally got nuclear magnetic resonance data. In the present work, molecular docking studies aimed is to investigate the limiting affinities of trans-dehydrocrotonin molecule and to identify the main amino acid residues that could play a fundamental role in their mechanism of action of the SARS-CoV spike protein. Another aim of this work is all about to evaluate 10 hybrid functionalities, along with three base pairs using computational programs to discover which ones are more reliable with the experimental result the best computational method to study organic compounds. We compared the results between the mean absolute deviation (MAD) and root-mean-square deviation (RMSD) of the molecules, and the smallest number between them was the best result. The positions assumed by the ligands in the active site of the spike glycoprotein allow assuming associations with different local amino acids.

Formation Characterization and Production Forecast of Tight Sandstone Formations in Daqing Oilfield Through Digital Rock Technology

2021 ◽  
Author(s):  
Danhua Leslie Zhang ◽  
Xiaodong Shi ◽  
Chunyan Qi ◽  
Jianfei Zhan ◽  
Xue Han ◽  
...  
Keyword(s):  
High Resolution ◽  
Capillary Pressure ◽  
Relative Permeability ◽  
Surfactant Solution ◽  
Fluid Models ◽  
Pore Scale ◽  
Field Development ◽  
Digital Rock ◽  
Small Pore ◽  
Sem Imaging

Abstract With the decline of conventional resources, the tight oil reserves in the Daqing oilfield are becoming increasingly important, but measuring relative permeability and determining production forecasts through laboratory core flow tests for tight formations are both difficult and time consuming. Results of laboratory testing are questionable due to the very small pore volume and low permeability of the reservoir rock, and there are challenges in controlling critical parameters during the special core analysis (SCAL) tests. In this paper, the protocol and workflow of a digital rock study for tight sandstones of the Daqing oilfield are discussed. The workflow includes 1) using a combination of various imaging methods to build rock models that are representative of reservoir rocks, 2) constructing digital fluid models of reservoir fluids and injectants, 3) applying laboratory measured wettability index data to define rock-fluid interaction in digital rock models, 4) performing pore-scale modelling to accelerate reservoir characterization and reduce the uncertainty, and 5) performing digital enhanced oil recovery (EOR) tests to analyze potential benefits of different scenarios. The target formations are tight (0.01 to 5 md range) sandstones that have a combination of large grain sizes juxtaposed against small pore openings which makes it challenging to select an appropriate set of imaging tools. To overcome the wide range of pore and grain scales, the imaging tools selected for the study included high resolution microCT imaging on core plugs and mini-plugs sampled from original plugs, overview scanning electron microscopy (SEM) imaging, mineralogical mapping, and high-resolution SEM imaging on the mini-plugs. High resolution digital rock models were constructed and subsequently upscaled to the plug level to differentiate bedding and other features could be differentiated. Permeability and porosity of digital rock models were benchmarked against laboratory measurements to confirm representativeness. The laboratory measured Amott-Harvey wettability index of restored core plugs was honored and applied to the digital rock models. Digital fluid models were built using the fluid PVT data. A Direct HydroDynamic (DHD) pore-scale flow simulator based on density functional hydrodynamics was used to model multiphase flow in the digital experiments. Capillary pressure, water-oil, surfactant solution-oil, and CO2-oil relative permeability were computed, as well as primary depletion followed with three-cycle CO2 huff-n-puff, and primary depletion followed with three-cycle surfactant solution huff-n-puff processes. Recovery factors were obtained for each method and resulting values were compared to establish most effective field development scenarios. The workflow developed in this paper provides fast and reliable means of obtaining critical data for field development design. Capillary pressure and relative permeability data obtained through digital experiments provide key input parameters for reservoir simulation; production scenario forecasts help evaluate various EOR methods. Digital simulations allow the different scenarios to be run on identical rock samples numerous times, which is not possible in the laboratory.

scholarly journals Evaluation of Novel N-(Dibenzylcarbamothioyl)benzamide Derivatives as Antibacterial Agents by Using DFT and Drug-Likeness Assessment

2018 ◽  
Vol 2018 ◽  
pp. 1-5 ◽  
Author(s):  
Huda Misral ◽  
Suhaila Sapari ◽  
Tajudin Rahman ◽  
Nazlina Ibrahim ◽  
Bohari M. Yamin ◽  
...  
Keyword(s):  
Density Functional ◽  
Molecular Descriptor ◽  
Inhibition Zone ◽  
Antibacterial Activities ◽  
Computational Method ◽  
Lipinski’S Rule ◽  
H Nmr ◽  
Elementary Analysis ◽  
Benzoyl Isothiocyanate

Isomers of monothioureas, 2a–2d, derived from the reaction of disubstituted benzoyl isothiocyanate and dibenzylamine were synthesised and characterised by using elementary analysis CHNS and IR, 1H NMR, and 13C NMR spectroscopies. The compounds were screened for their in vitro antibacterial activity by using selected Gram-positive bacteria, and moderate inhibition activity was displayed for compound 2b with the value of inhibition zone 11 ± 0.8 mm at a concentration of 50 mg/ml. The outcomes of Lipinski’s rule of five assessment appeared to be in agreement with all compounds as they adhered to most of the rules, in which they can be preliminarily classified as active drug-like. The frontier molecular orbitals (HOMO and LUMO) for halogen-substituted 3,4-dichloro (2a) and 3,4-difluoro (2b) were also determined by applying the computational method of density functional theory (DFT) to determine their relationship as a molecular descriptor in antibacterial activities. The value of LUMO energy for compound 2b (1.8229 eV) is lower than that of compound 2a (1.8492 eV) which indicates higher antibacterial activities.

scholarly journals Phosphate-Catalyzed Succinimide Formation from an NGR-Containing Cyclic Peptide: A Novel Mechanism for Deammoniation of the Tetrahedral Intermediate

Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2217 ◽  
Author(s):  
Ryota Kirikoshi ◽  
Noriyoshi Manabe ◽  
Ohgi Takahashi
Keyword(s):  
Conformational Changes ◽  
Density Functional ◽  
Cyclic Peptide ◽  
Density Functional Theory Method ◽  
Proton Exchange ◽  
Computational Method ◽  
Side Chain ◽  
Tetrahedral Intermediate ◽  
Rate Determining Step ◽  
Proton Source

Spontaneous deamidation in the Asn-Gly-Arg (NGR) motif that yields an isoAsp-Gly-Arg (isoDGR) sequence has recently attracted considerable attention because of the possibility of application to dual tumor targeting. It is well known that Asn deamidation reactions in peptide chains occur via the five-membered ring succinimide intermediate. Recently, we computationally showed by the B3LYP density functional theory method, that inorganic phosphate and the Arg side chain can catalyze the NGR deamidation using a cyclic peptide, c[CH2CO–NGRC]–NH2. In this previous study, the tetrahedral intermediate of the succinimide formation was assumed to be readily protonated at the nitrogen originating from the Asn side chain by the solvent water before the release of an NH3 molecule. In the present study, we found a new mechanism for the decomposition of the tetrahedral intermediate that does not require the protonation by an external proton source. The computational method is the same as in the previous study. In the new mechanism, the release of an NH3 molecule occurs after a proton exchange between the peptide and the phosphate and conformational changes. The rate-determining step of the overall reaction course is the previously reported first step, i.e., the cyclization to form the tetrahedral intermediate.

scholarly journals Density Functional Hydrodynamics in Multiscale Pore Systems: Chemical Potential Drive

2020 ◽  
Vol 146 ◽  
pp. 01001
Author(s):  
Oleg Dinariev ◽  
Nikolay Evseev ◽  
Denis Klemin
Keyword(s):  
Density Functional ◽  
Fluid Transport ◽  
Chemical Potential ◽  
Transport Model ◽  
Effective Model ◽  
Pore Scale ◽  
Multiphase Transport ◽  
Novel Approach ◽  
Scale Modelling ◽  
Significant Generalization

We use the method of density functional hydrodynamics (DFH) to model compositional multiphase flows in natural cores at the pore-scale. In previous publications the authors demonstrated that DFH covers many diverse pore-scale phenomena, starting from those inherent in RCA and SCAL measurements, and extending to much more complex EOR processes. We perform the pore-scale modelling of multiphase flow scenarios by means of the direct hydrodynamic (DHD) simulator, which is a numerical implementation of the DFH. In the present work, we consider the problem of numerical modelling of fluid transport in pore systems with voids and channels when the range of pore sizes exceed several orders of magnitude. Such situations are well known for carbonate reservoirs, where narrow pore channels of micrometer range can coexist and interconnect with vugs of millimeter or centimeter range. In such multiscale systems one cannot use the standard DFH approach for pore-scale modeling, primarily because the needed increase in scanning resolution that is required to resolve small pores adequately, leads to a field of view reduction that compromises the representation of large pores. In order to address this challenge, we suggest a novel approach, in which transport in small-size pores is described by an upscaled effective model, while the transport in large pores is still described by the DFH. The upscaled effective model is derived from the exact DFH equations using asymptotic expansion in respect to small-size characterization parameter. This effective model retains the properties of DFH like chemical and multiphase transport, thus making it applicable to the same range of phenomena as DFH itself. The model is based on the concept that the transport is driven by gradients of chemical potentials of the components present in the mixture. This is a significant generalization of the Darcy transport model since the proposed new model incorporates diffusion transport in addition to the usual pressure-driven transport. In the present work we provide several multiphase transport numerical examples including: a) upscaling to chemical potential drive (CPD) model, b) combined modeling of large pores by DFH and small pores by CPD.

Integrated Field Development Planning for Enhanced Condensate Recovery ECR and Gas Storage in Mature Gas Condensate Fields

2018 ◽  
Author(s):  
Harshil Saradva ◽  
Siddharth Jain ◽  
Mark Sarssam ◽  
Masoud Al Hamadi ◽  
Matthew Robert
Keyword(s):  
Gas Storage ◽  
Development Planning ◽  
Gas Condensate ◽  
Field Development

Correlating Recovery Efficiency to Pore Throat Characteristics using Digital Rock Analysis

2015 ◽  
Author(s):  
Dandan Hu ◽  
Douglas Wyatt ◽  
Cheng Chen ◽  
Vladimir Martysevich
Keyword(s):  
Recovery Efficiency ◽  
Pore Throat ◽  
Digital Rock ◽  
Rock Analysis

First-principle studies of the lattice dynamics of crystals, and related properties

2005 ◽  
Vol 220 (5/6) ◽  
Author(s):  
Xavier Gonze ◽  
Gian-Marco Rignanese ◽  
Razvan Caracas
Keyword(s):  
Perturbation Theory ◽  
First Principles ◽  
Lattice Dynamics ◽  
Density Functional ◽  
Computational Method ◽  
Dielectric Tensor ◽  
Atomic Temperature ◽  
Density Functional Perturbation Theory ◽  
Infra Red ◽  
Temperature Factors

AbstractThe crystal lattice is never rigid. Due to temperature, external fields or pressure, the nuclei vibrate, the lattice distorts, and instabilities can induce phase transitions. We review the basic concepts of density-functional perturbation theory, a computational method especially suited to determine from first-principles the microscopic parameters governing such behaviour. Then, we present the additional formalism leading to the following properties of minerals: the infra-red and Raman spectra; the prediction of (meta)stability or instability of a crystalline phase, based on the phonon spectrum; the computation of thermodynamics quantities like the free energy, entropy, specific heat; the atomic temperature factors. For each property, examples are given. When appropriate, we mention the computation of related properties, like dielectric tensor and Born effective charges that are needed to get infra-red spectra. Finally, we discuss briefly, on one hand, other applications of the density-functional perturbation theory, and, on the other hand, an alternative technique, the finite-difference computation of dynamical matrices.

Sign in / Sign up

Export Citation Format

Share Document