scholarly journals Chemical Compositions in Salinity Waterflooding of Carbonate Reservoirs: Theory

2020 ◽  
Author(s):  
Maxim Yutkin ◽  
Clayton J. Radke ◽  
Tadeusz Patzek
Keyword(s):  
Mass Transfer ◽  
Ion Exchange ◽  
Reactive Transport ◽  
Carbonate Rock ◽  
Reaction Rates ◽  
Companion Paper ◽  
Contact Angles ◽  
Carbonate Reservoirs ◽  
Reservoir Rock ◽  
Chemical Compositions

Higher oil recovery after waterflood in carbonate reservoirs is attributed to increasing water wettability of the rock that in turn relies on complicated surface chemistry. However, calcite mineral reacts with<br>aqueous solutions, and can alter substantially the composition of injected water by mineral dissolution. Care-<br>fully designed chemical and/or brine flood compositions in the laboratory may not remain intact while the<br>injected solutions pass through the reactive reservoir rock. This is especially true for a low-salinity waterflood<br>process, where some finely-tuned brine compositions can improve flood performances, whereas others cannot.<br>We present a 1D reactive transport numerical model that captures the changes in injected compositions dur-<br>ing water flow through porous carbonate rock. We include highly coupled bulk aqueous and surface carbonate-<br>reaction chemistry, detailed reaction and mass transfer kinetics, 2:1 calcium ion exchange, and axial dispersion.<br>At typical calcite reaction rates, local equilibrium is established immediately upon injection. Using an open-<br>source algorithm (Charlton and Parkhurst 2011), we present a design tool to specify chemical/brine flooding<br>packages that correct for composition alteration by carbonate rock.<br>Here, we present a comprehensive 1D reactive transport model and validate it against analytic solutions<br>for rock dissolution, ion exchange, and longitudinal dispersion, each considered separately. A companion paper<br>compares the proposed theory against experiments on core plugs of Indiana limestone that serve as high velocity<br>probes for reaction-controlled and mass-transfer-controlled dissolution. Finally, in another companion paper,<br>we give examples of how injected salinity compositions deviate from those designed in the laboratory for water-<br>wettability improvement based on contact angles, zeta potentials, surface charge densities, and ion exchange.<br>How to correct the design chemical packages for exposure to reactive rock is also discussed in there.

scholarly journals Chemical Compositions in Salinity Waterflooding of Carbonate Reservoirs: Theory

2020 ◽  
Author(s):  
Maxim Yutkin ◽  
Clayton J. Radke ◽  
Tadeusz Patzek
Keyword(s):  
Mass Transfer ◽  
Ion Exchange ◽  
Reactive Transport ◽  
Carbonate Rock ◽  
Reaction Rates ◽  
Companion Paper ◽  
Contact Angles ◽  
Carbonate Reservoirs ◽  
Reservoir Rock ◽  
Chemical Compositions

Higher oil recovery after waterflood in carbonate reservoirs is attributed to increasing water wettability of the rock that in turn relies on complicated surface chemistry. However, calcite mineral reacts with<br>aqueous solutions, and can alter substantially the composition of injected water by mineral dissolution. Care-<br>fully designed chemical and/or brine flood compositions in the laboratory may not remain intact while the<br>injected solutions pass through the reactive reservoir rock. This is especially true for a low-salinity waterflood<br>process, where some finely-tuned brine compositions can improve flood performances, whereas others cannot.<br>We present a 1D reactive transport numerical model that captures the changes in injected compositions dur-<br>ing water flow through porous carbonate rock. We include highly coupled bulk aqueous and surface carbonate-<br>reaction chemistry, detailed reaction and mass transfer kinetics, 2:1 calcium ion exchange, and axial dispersion.<br>At typical calcite reaction rates, local equilibrium is established immediately upon injection. Using an open-<br>source algorithm (Charlton and Parkhurst 2011), we present a design tool to specify chemical/brine flooding<br>packages that correct for composition alteration by carbonate rock.<br>Here, we present a comprehensive 1D reactive transport model and validate it against analytic solutions<br>for rock dissolution, ion exchange, and longitudinal dispersion, each considered separately. A companion paper<br>compares the proposed theory against experiments on core plugs of Indiana limestone that serve as high velocity<br>probes for reaction-controlled and mass-transfer-controlled dissolution. Finally, in another companion paper,<br>we give examples of how injected salinity compositions deviate from those designed in the laboratory for water-<br>wettability improvement based on contact angles, zeta potentials, surface charge densities, and ion exchange.<br>How to correct the design chemical packages for exposure to reactive rock is also discussed in there.

scholarly journals Chemical Compositions in Salinity Waterflooding of Carbonate Reservoirs: Theory

2020 ◽  
Author(s):  
Maxim Yutkin ◽  
Clayton J. Radke ◽  
Tadeusz Patzek
Keyword(s):  
Mass Transfer ◽  
Ion Exchange ◽  
Reactive Transport ◽  
Carbonate Rock ◽  
Reaction Rates ◽  
Companion Paper ◽  
Contact Angles ◽  
Carbonate Reservoirs ◽  
Reservoir Rock ◽  
Chemical Compositions

Higher oil recovery after waterflood in carbonate reservoirs is attributed to increasing water wettability of the rock that in turn relies on complicated surface chemistry. However, calcite mineral reacts with<br>aqueous solutions, and can alter substantially the composition of injected water by mineral dissolution. Care-<br>fully designed chemical and/or brine flood compositions in the laboratory may not remain intact while the<br>injected solutions pass through the reactive reservoir rock. This is especially true for a low-salinity waterflood<br>process, where some finely-tuned brine compositions can improve flood performances, whereas others cannot.<br>We present a 1D reactive transport numerical model that captures the changes in injected compositions dur-<br>ing water flow through porous carbonate rock. We include highly coupled bulk aqueous and surface carbonate-<br>reaction chemistry, detailed reaction and mass transfer kinetics, 2:1 calcium ion exchange, and axial dispersion.<br>At typical calcite reaction rates, local equilibrium is established immediately upon injection. Using an open-<br>source algorithm (Charlton and Parkhurst 2011), we present a design tool to specify chemical/brine flooding<br>packages that correct for composition alteration by carbonate rock.<br>Here, we present a comprehensive 1D reactive transport model and validate it against analytic solutions<br>for rock dissolution, ion exchange, and longitudinal dispersion, each considered separately. A companion paper<br>compares the proposed theory against experiments on core plugs of Indiana limestone that serve as high velocity<br>probes for reaction-controlled and mass-transfer-controlled dissolution. Finally, in another companion paper,<br>we give examples of how injected salinity compositions deviate from those designed in the laboratory for water-<br>wettability improvement based on contact angles, zeta potentials, surface charge densities, and ion exchange.<br>How to correct the design chemical packages for exposure to reactive rock is also discussed in there.

scholarly journals Chemical Compositions in Salinity Waterflooding of Carbonate Reservoirs: Theory

2021 ◽  
Vol 136 (2) ◽  
pp. 411-429
Author(s):  
M. P. Yutkin ◽  
C. J. Radke ◽  
T. W. Patzek
Keyword(s):  
Ion Exchange ◽  
Reactive Transport ◽  
Carbonate Rock ◽  
Reaction Rates ◽  
Design Tool ◽  
Mineral Dissolution ◽  
Carbonate Reservoirs ◽  
Reservoir Rock ◽  
Chemical Compositions ◽  
Water Wettability

AbstractHigher oil recovery after waterflood in carbonate reservoirs is attributed to increasing water wettability of the rock that in turn relies on complicated surface chemistry. In addition, calcite mineral reacts with aqueous solutions and can alter substantially the composition of injected water by mineral dissolution. Carefully designed chemical and/or brine flood compositions in the laboratory may not remain intact while the injected solutions pass through the reactive reservoir rock. This is especially true for a low-salinity waterflood process, where some finely tuned brine compositions can improve flood performances, whereas others cannot. We present a 1D reactive transport numerical model that captures the changes in injected compositions during water flow through porous carbonate rock. We include highly coupled bulk aqueous and surface carbonate-reaction chemistry, detailed reaction and mass transfer kinetics, 2:1 calcium ion exchange, and axial dispersion. At typical calcite reaction rates, local equilibrium is established immediately upon injection. In SI, we validate the reactive transport model against analytic solutions for rock dissolution, ion exchange, and longitudinal dispersion, each considered separately. Accordingly, using an open-source algorithm (Charlton and Parkhurst in Comput Geosci 37(10):1653–1663, 2011. 10.1016/j.cageo.2011.02.005), we outline a design tool to specify chemical/brine flooding formulations that correct for composition alteration by the carbonate rock. Subsequent works compare proposed theory against experiments on core plugs of Indiana limestone and give examples of how injected salinity compositions deviate from those designed in the laboratory for water-wettability improvement.

A Mechanistic Model for Wettability Alteration by Chemically Tuned Waterflooding in Carbonate Reservoirs

SPE Journal ◽  
2015 ◽  
Vol 20 (04) ◽  
pp. 767-783 ◽  
Author(s):  
C.. Qiao ◽  
L.. Li ◽  
R.T.. T. Johns ◽  
J.. Xu
Keyword(s):  
Experimental Data ◽  
Oil Recovery ◽  
Carbonate Rocks ◽  
Reactive Transport ◽  
Mechanistic Model ◽  
Contact Angles ◽  
Carbonate Reservoirs ◽  
Wettability Alteration ◽  
Physical Parameters ◽  
Minor Effect

Summary Injection of chemically tuned brines into carbonate reservoirs has been reported to enhance oil recovery by 5–30% original oil in place (OOIP) in coreflooding experiments and field tests. One proposed mechanism for this improved oil recovery (IOR) is wettability alteration of rock from oil-wet or mixed-wet to more-water-wet conditions. Modeling of wettability-alteration experiments, however, is challenging because of the complex interactions among ions in the brine and crude oil on the solid surface. In this research, we developed a multiphase and multicomponent reactive transport model that explicitly takes into account wettability alteration from these geochemical interactions in carbonate reservoirs. Published experimental data suggest that desorption of acidic-oil components from rock surfaces make carbonate rocks more water-wet. One widely accepted mechanism is that sulfate (SO42−) replaces the adsorbed carboxylic group from the rock surface, whereas cations (Ca2+, Mg2+) decrease the oil-surface potential. In the proposed mechanistic model, we used a reaction network that captures the competitive surface reactions among carboxylic groups, cations, and sulfate. These reactions control the wetting fractions and contact angles, which subsequently determine the capillary pressure, relative permeabilities, and residual oil saturations. The developed model was first tuned with experimental data from the Stevns Klint chalk and then used to predict oil recovery for additional untuned experiments under a variety of conditions where IOR increased by as much as 30% OOIP, depending on salinity and oil acidity. The numerical results showed that an increase in sulfate concentration can lead to an IOR of more than 40% OOIP, whereas cations such as Ca2+ have a relatively minor effect on recovery (approximately 5% OOIP). Physical parameters, including the total surface area of the rock and the diffusion coefficients, control the rate of recovery, but not the final oil recovery. The simulation results further demonstrate that the optimum brine formulations for chalk are those with relatively abundant SO42− (0.096 mol/kg water), moderate concentrations of cations, and low salinity (total ionic strength of less than 0.2 mol/kg water). These findings are consistent with the experimental data reported in the literature. The new model provides a powerful tool to predict the IOR potential of chemically tuned waterflooding in carbonate reservoirs under different scenarios. To the best of our knowledge, this is the first model that explicitly and mechanistically couples multiphase flow and multicomponent surface complexation with wettability alteration and oil recovery for carbonate rocks specifically.

scholarly journals Implementing the Variability of Crystal Surface Reactivity in Reactive Transport Modeling

2021 ◽  
Author(s):  
Torben Prill ◽  
Cornelius Fischer ◽  
Pavel Gavrilenko ◽  
Oleg Iliev
Keyword(s):  
Contaminated Soils ◽  
Reactive Transport ◽  
Transport Model ◽  
Crystal Surface ◽  
Reaction Rates ◽  
Surface Reactivity ◽  
Reservoir Rock ◽  
Intrinsic Variability ◽  
Multiple Systems ◽  
The Difference

AbstractCurrent reactive transport model (RTM) uses transport control as the sole arbiter of differences in reactivity. For the simulation of crystal dissolution, a constant reaction rate is assumed for the entire crystal surface as a function of chemical parameters. However, multiple dissolution experiments confirmed the existence of an intrinsic variability of reaction rates, spanning two to three orders of magnitude. Modeling this variance in the dissolution process is vital for predicting the dissolution of minerals in multiple systems. Novel approaches to solve this problem are currently under discussion. Critical applications include reactions in reservoir rocks, corrosion of materials, or contaminated soils. The goal of this study is to provide an algorithm for multi-rate dissolution of single crystals, to discuss its software implementation, and to present case studies illustrating the difference between the single rate and multi-rate dissolution models. This improved model approach is applied to a set of test cases in order to illustrate the difference between the new model and the standard approach. First, a Kossel crystal is utilized to illustrate the existence of critical rate modes of crystal faces, edges, and corners. A second system exemplifies the effect of multiple rate modes in a reservoir rock system during calcite cement dissolution in a sandstone. The results suggest that reported variations in average dissolution rates can be explained by the multi-rate model, depending on the geometric configurations of the crystal surfaces.

A Novel Pore-Scale Thermal-Fracture-Acidizing Model With Heterogeneous Rock Properties

SPE Journal ◽  
2016 ◽  
Vol 21 (01) ◽  
pp. 280-292 ◽  
Author(s):  
John Lyons ◽  
Hadi Nasrabadi ◽  
Hisham A. Nasr-El-Din
Keyword(s):  
Mass Transfer ◽  
Reactive Transport ◽  
Reaction Rate ◽  
Oil And Gas ◽  
Injection Rate ◽  
Rock Properties ◽  
Thermal Fracture ◽  
Pore Scale ◽  
Heterogeneous Rock ◽  
Acid Reaction

Summary Fracture acidizing is a well-stimulation technique used to improve the productivity of low-permeability reservoirs and to bypass deep formation damage. The reaction of injected acid with the rock matrix forms etched channels through which oil and gas can then flow upon production. The properties of these etched channels depend on the acid-injection rate, temperature, reaction chemistry, mass-transport properties, and formation mineralogy. As the acid enters the formation, it increases in temperature by heat exchange with the formation and the heat generated by acid reaction with the rock. Thus, the reaction rate, viscosity, and mass transfer of acid inside the fracture also increase. In this study, a new thermal-fracture-acidizing model is presented that uses the lattice Boltzmann method to simulate reactive transport. This method incorporates both accurate hydrodynamics and reaction kinetics at the solid/liquid interface. The temperature update is performed by use of a finite-difference technique. Furthermore, heterogeneity in rock properties (e.g., porosity, permeability, and reaction rate) is included. The result is a model that can accurately simulate realistic fracture geometries and rock properties at the pore scale and that can predict the geometry of the fracture after acidizing. Three thermal-fracture-acidizing simulations are presented here, involving injection of 15 and 28 wt% of hydrochloric acid into a calcite fracture. The results clearly show an increase in the overall fracture dissolution because of the addition of temperature effects (increasing the acid-reaction and mass-transfer rates). It has also been found that by introducing mineral heterogeneity, preferential dissolution leads to the creation of uneven etching across the fracture surfaces, indicating channel formation.

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