Analytical Solutions for the Injection of Wettability Modifiers in Carbonate Reservoirs Based on a Reduced Surface Complexation Model

Mapping Intimacies ◽

10.2118/206088-ms ◽

2021 ◽

Author(s):

Ricardo A. Lara Orozco ◽

Ryosuke Okuno ◽

Larry W. Lake

Keyword(s):

Anion Exchange ◽

Surface Potential ◽

Analytical Solutions ◽

Electrostatic Interactions ◽

Surface Complexation ◽

Carbonate Reservoirs ◽

Wettability Alteration ◽

Exchange Reactions ◽

Complexation Reactions ◽

The Impact

Abstract The potential of tuned-composition waterflooding to enhance oil recovery from carbonate reservoirs has been widely investigated in the literature. The consensus is that wettability alteration occurs because of the electrostatic interactions between the carbonate rock surface and the potential determining ions, Ca2+, Mg2+, CO32−, and SO42−. Recently, glycine, the simplest amino acid, has also been investigated as a wettability modifier for carbonates that acts similarly as the sulfate ions in brine. The impact of wettability modifiers like glycine and calcite's potential determining ions has been described by surface complexation models (SCM) and the wetting-state of the rock has been related to change of the surface potential. However, determining the relevance of the geochemical reactions is obstructed by the complexity of the SCM. Moreover, the surface potential as a surrogate of the wetting-state of the rock does not correlate with the experimental results with glycine reported in the literature. The present research analyzed the results of single-phase displacement using a SCM for calcite to determine the important surface complexation reactions. Then, wettability alteration is modeled as a set of anion exchange reactions between wettability modifiers, like SO42− and Gly−, and adsorbed carboxylic acids. Finally, analytical solutions are presented for the coupled two-phase and multicomponent reactive-transport model with anion exchange reactions.

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Oil Recovery Mechanisms During Sequential Injection of Chelating Agent Solutions Into Carbonate Rocks

Journal of Energy Resources Technology ◽

10.1115/1.4044226 ◽

2019 ◽

Vol 142 (1) ◽

Cited By ~ 4

Author(s):

Amjed M. Hassan ◽

Hasan S. Al-Hashim

Keyword(s):

Oil Recovery ◽

Chelating Agent ◽

Carbonate Reservoirs ◽

Analytical Models ◽

Productivity Index ◽

Wettability Alteration ◽

Permeability Enhancement ◽

Recovery Mechanisms ◽

The Impact

Chelating agent solutions have been proposed as effective fluids for enhancing oil production. Different recovery mechanisms are reported for increasing the oil recovery during chelating agent flooding. The aims of this work are to identify the possible recovery mechanisms during chelating agent flooding in carbonate reservoirs and to investigate the in situ CO2 generation as a potential recovery mechanism during the injection of chelating agent solutions into carbonate reservoirs. The contribution of CO2 on enhancing the oil recovery was determined using experimental measurements and analytical calculations. Several measurements were conducted to study the contribution of each mechanism on enhancing the oil recovery. Coreflooding tests, zeta potential measurements, CO2 generation, and interfacial tension (IFT) experiments were carried out. Also, analytical models were utilized to determine the impact of the injected chemicals on reducing the capillary pressure and improving the flow conditions. In flooding tests, two chemicals (EDTA and GLDA) were injected in a sequential mode and the chemical concentration was increased gradually. In addition, a comparative study was performed to evaluate the effectiveness of EDTA and GLDA solutions to enhance oil recovery. Several parameters were investigated in this paper including incremental oil recovery, in situ CO2 generation, hydrocarbon swelling, IFT, wettability alteration, permeability enhancement, productivity index, and chemical cost. The obtained results show that GLDA chelating agent has better performance than EDTA solutions for enhancing the oil recovery when the same concentrations are used. Also, the in situ generation of CO2 shows a significant impact on improving the oil recovery from carbonate reservoirs during chelating agent flooding. In the literature, the reported recovery mechanisms of using chelating agents are the IFT reduction, wettability alteration, and rock dissolution. Based on this work, injecting chelating agent solutions at low pH can lead to involve additional recovery mechanisms due to the CO2 generation, the additional mechanisms are hydrocarbon swelling, viscosity and density reduction, and oil vaporization.

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New Approach to Assess the Impact of Wettability Alteration on rock compaction of carbonate reservoirs

10.3997/2214-4609.202187007 ◽

2021 ◽

Author(s):

F. Amrouche ◽

D. Xu

Keyword(s):

Carbonate Reservoirs ◽

Wettability Alteration ◽

New Approach ◽

The Impact

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An Analytical Modeling and Performance Analysis of Graded Work Function Gate Recessed Channel SOI-MOSFET

Nanoscience &Nanotechnology-Asia ◽

10.2174/2210681208666180820151121 ◽

2019 ◽

Vol 9 (4) ◽

pp. 504-511

Author(s):

Sikha Mishra ◽

Urmila Bhanja ◽

Guru Prasad Mishra

Keyword(s):

Analytical Model ◽

Surface Potential ◽

Threshold Voltage ◽

Silicon On Insulator ◽

Junction Depth ◽

Short Channel ◽

Soi Mosfet ◽

Minimum Surface ◽

Recessed Channel ◽

The Impact

Introduction: A new analytical model is designed for Workfunction Modulated Rectangular Recessed Channel-Silicon On Insulator (WMRRC-SOI) MOSFET that considers the concept of groove gate and implements an idea of workfunction engineering. Methods: The impact of Negative Junction Depth (NJD) and oxide thickness (tox) are analyzed on device performances such as Sub-threshold Slope (SS), Drain Induced Barrier Lowering (DIBL) and threshold voltage. Results: The results of the proposed work are evaluated with the Rectangular Recessed Channel-Silicon On Insulator (RRC-SOI) MOSFET keeping the metal workfunction constant throughout the gate region. Furthermore, an analytical model is developed using 2D Poisson’s equation and threshold voltage is estimated in terms of minimum surface potential. Conclusion: In this work, the impact of Negative Junction Depth (NJD) on minimum surface potential and the drain current are also evaluated. It is observed from the analysis that the analog switching performance of WMRRC-SOI MOSFET surpasses RRC-SOI MOSFET in terms of better driving capability, high Ion/Ioff ratio, minimized Short Channel Effects (SCEs) and hot carrier immunity. Results are simulated using 2D Sentaurus TCAD simulator for validation of the proposed structure.

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Cooperation/Competition between Halogen Bonds and Hydrogen Bonds in Complexes of 2,6-Diaminopyridines and X-CY3 (X = Cl, Br; Y = H, F)

Symmetry ◽

10.3390/sym13050766 ◽

2021 ◽

Vol 13 (5) ◽

pp. 766

Author(s):

Barbara Bankiewicz ◽

Marcin Palusiak

Keyword(s):

Complex Formation ◽

Hydrogen Bonds ◽

Dft Calculations ◽

Electrostatic Interactions ◽

Dipole Moments ◽

Main Role ◽

Halogen Bonds ◽

Topological Parameters ◽

Leading Role ◽

The Impact

The DFT calculations have been performed on a series of two-element complexes formed by substituted 2,6-diaminopyridine (R−PDA) and pyridine (R−Pyr) with X−CY3 molecules (where X = Cl, Br and Y = H, F). The primary aim of this study was to examine the intermolecular hydrogen and halogen bonds in the condition of their mutual coexistence. Symmetry/antisymmetry of the interrelation between three individual interactions is addressed. It appears that halogen bonds play the main role in the stabilization of the structures of the selected systems. However, the occurrence of one or two hydrogen bonds was associated with the favourable geometry of the complexes. Moreover, the impact of different substituent groups attached in the para position to the aromatic ring of the 2,6-diaminopyridine and pyridine on the character of the intermolecular hydrogen and halogen bonds was examined. The results indicate that the presence of electron-donating substituents strengthens the bonds. In turn, the presence of electron-withdrawing substituents reduces the strength of halogen bonds. Additionally, when hydrogen and halogen bonds lose their leading role in the complex formation, the nonspecific electrostatic interactions between dipole moments take their place. Analysis was based on geometric, energetic, and topological parameters of the studied systems.

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Impact of anion exchange adsorbents on regional citrate anticoagulation

The International Journal of Artificial Organs ◽

10.1177/0391398820947733 ◽

2020 ◽

pp. 039139882094773

Author(s):

Karin Strobl ◽

Stephan Harm ◽

Ute Fichtinger ◽

Claudia Schildböck ◽

Jens Hartmann

Keyword(s):

Anion Exchange ◽

Regional Citrate Anticoagulation ◽

Liver Support ◽

Anion Exchange Resins ◽

Increased Risk ◽

Extracorporeal Liver Support ◽

Target Molecules ◽

Exchange Resins ◽

The Impact

Introduction: Heparin and citrate are commonly used anticoagulants in membrane/adsorption based extracorporeal liver support systems. However, anion exchange resins employed for the removal of negatively charged target molecules including bilirubin may also deplete these anticoagulants due to their negative charge. The aim of this study was to evaluate the adsorption of citrate by anion exchange resins and the impact on extracorporeal Ca2+ concentrations. Methods: Liver support treatments were simulated in vitro. Citrate and Ca2+ concentrations were measured pre and post albumin filter as well as pre and post adsorbents. In addition, batch experiments were performed to quantify citrate adsorption. Results: Pre albumin filter target Ca2+ concentrations were reached well with only minor deviations. Citrate was adsorbed by anion exchange resins, resulting in a higher Ca2+ concentration downstream of the adsorbent cartridges during the first hour of treatment. Conclusions: The anion exchange resin depletes citrate, leading to an increased Ca2+ concentration in the extracorporeal circuit, which may cause an increased risk of clotting during the first hour of treatment. An increase of citrate infusion during the first hour of treatment should therefore be considered to compensate for the adsorption of citrate.

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Understanding Calcite Wettability Alteration through Surface Potential Measurements and Molecular Simulations

The Journal of Physical Chemistry C ◽

10.1021/acs.jpcc.7b09565 ◽

2017 ◽

Vol 121 (50) ◽

pp. 28017-28030 ◽

Cited By ~ 2

Author(s):

Sarah M. Walker ◽

Maria C. Marcano ◽

Sooyeon Kim ◽

Sandra D. Taylor ◽

Udo Becker

Keyword(s):

Surface Potential ◽

Molecular Simulations ◽

Wettability Alteration ◽

Surface Potential Measurements

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A Novel Coreflood Test to Evaluate EOR Potential of Wettability-Altering Surfactants in Oil-Wet Heterogeneous Carbonate Reservoirs

10.2118/206151-ms ◽

2021 ◽

Author(s):

Yue Shi ◽

Kishore Mohanty ◽

Manmath Panda

Keyword(s):

Oil Recovery ◽

Carbonate Reservoirs ◽

Wettability Alteration ◽

Low Permeability ◽

High Permeability ◽

Matrix Permeability ◽

Rock Heterogeneity ◽

The Matrix ◽

Flow Through ◽

Main Factors

Abstract Oil-wetness and heterogeneity (i.e., existence of low and high permeability regions) are two main factors that result in low oil recovery by waterflood in carbonate reservoirs. The injected water is likely to flow through high permeability regions and bypass the oil in low permeability matrix. In this study, systematic coreflood tests were carried out in both "homogeneous" cores and "heterogeneous" cores. The heterogeneous coreflood test was proposed to model the heterogeneity of carbonate reservoirs, bypassing in low-permeability matrix during waterfloods, and dynamic imbibition of surfactant into the low-permeability matrix. The results of homogeneous coreflood tests showed that both secondary-waterflood and secondary-surfactant flood can achieve high oil recovery (>50%) from relatively homogenous cores. A shut-in phase after the surfactant injection resulted in an additional oil recovery, which suggests enough time should be allowed while using surfactants for wettability alteration. The core with a higher extent of heterogeneity produced lower oil recovery to waterflood in the coreflood tests. Final oil recovery from the matrix depends on matrix permeability as well as the rock heterogeneity. The results of heterogeneous coreflood tests showed that a slow surfactant injection (dynamic imbibition) can significantly improve the oil recovery if the oil-wet reservoir is not well-swept.

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The New Flow Control Devices Autonomously Controlling the Performance of Matrix Acid Stimulation Operations in Carbonate Reservoirs

10.2118/205975-ms ◽

2021 ◽

Author(s):

Mojtaba Moradi ◽

Michael R Konopczynski

Keyword(s):

Flow Control ◽

Dynamic Change ◽

Injection Rate ◽

Control Flow ◽

Carbonate Reservoir ◽

Operating Conditions ◽

Carbonate Reservoirs ◽

High Permeability ◽

The Impact ◽

Stimulation Of

Abstract Matrix acidizing is a common but complex stimulation treatment that could significantly improve production/injection rate, particularly in carbonate reservoirs. However, the desired improvement in all zones of the well by such operation may not be achieved due to existing and/or developing reservoir heterogeneity. This paper describes how a new flow control device (FCD) previously used to control water injection in long horizontal wells can also be used to improve the conformance of acid stimulation in carbonate reservoirs. Acid stimulation of a carbonate reservoir is a positive feedback process. Acid preferentially takes the least resistant path, an area with higher permeability or low skin. Once acid reacts with the formation, the injectivity in that zone increases, resulting in further preferential injection in the stimulated zone. Over-treating a high permeability zone results in poor distribution of acid to low permeability zones. Mechanical, chemical or foam diversions have been used to improve stimulation conformance along the wellbore, however, they may fail in carbonate reservoirs with natural fractures where fracture injectivity dominates the stimulation process. A new FCD has been developed to autonomously control flow and provide mechanical diversion during matrix stimulation. Once a predefined upper limit flowrate is reached at a zone, the valve autonomously closes. This eliminates the impact of thief zone on acid injection conformance and maintains a prescribed acid distribution. Like other FCDs, this device is installed in several compartments in the wells. The device has two operating conditions, one, as a passive outflow control valve, and two, as a barrier when the flow rate through the valve exceeds a designed limit, analogous to an electrical circuit breaker. Once a zone has been sufficiently stimulated by the acid and the injection rate in that zone exceeds the device trip point, the device in that zone closes and restricts further stimulation. Acid can then flow to and stimulate other zones This process can be repeated later in well life to re-stimulate zones. This performance enables the operators to minimise the impacts of high permeability zones on the acid conformance and to autonomously react to a dynamic change in reservoirs properties, specifically the growth of wormholes. The device can be installed as part of lower completions in both injection and production wells. It can be retrofitted in existing completions or be used in a retrievable completion. This technology allows repeat stimulation of carbonate reservoirs, providing mechanical diversion without the need for coiled tubing or other complex intervention. This paper will briefly present an overview of the device performance, flow loop testing and some results from numerical modelling. The paper also discusses the completion design workflow in carbonates reservoirs.

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