Imbibition Rate Research Articles

Aqueous extract of coconut shell biochar as a pre-germination treatment increases seed germination and early seedling growth in chiltepín pepper (Capsicum annuum var. glabriusculum)

Since the fruit of the Capsicum annuum L. var. glabriusculum (Dunal) Heiser and Pickergil (chiltepín pepper) has a low germination rate, we sought to determine whether using an aqueous biochar extract could improve this. Germination tests were performed out in Petri dishes, using wild chiltepín pepper seeds collected in Sonora, México, which were exposed for 24 h to aqueous extracts of coconut shell biochar (CSBA) at different doses (0.05, 0.10, 0.25, 0.50, 0.75, and 1.00%, w/v) and a control comprising deionized water. In addition to quantifying the germination rate, we determined the physical quality, viability, imbibition, electrical conductivity, seed pH, and capsaicin content. The fast green test showed an ideal physical quality (p = 0.5475), an imbibition rate > 65% (p > 0.05), and high viability 98.4% (p > 0.05). The wild chiltepín pepper seeds exposed to the CSBA0.05 and CSBA0.25 treatments increased the percentage germination rate (p < 0.001) to 80.9% and 71.7%, respectively. A higher percentage of normal seedlings resulted from CSBA0.05, CSBA0.10 and CSBA1.00 (p < 0.01), and a greater shoot length was obtained with CSBA0.05 (p < 0.01). The exposure of wild chiltepín seeds to aqueous CSBA for 24 h at low doses (CSBA0.05 and CSBA0.25) increase the germination rate, while CSBA0.05 could enhance early seedling growth.

Early- and Late-Time Prediction of Counter-Current Spontaneous Imbibition, Scaling Analysis and Estimation of the Capillary Diffusion Coefficient

Solutions are investigated for 1D linear counter-current spontaneous imbibition (COUSI). It is shown theoretically that all COUSI scaled solutions depend only on a normalized coefficient {Lambda }_{n}left({S}_{n}right) with mean 1 and no other parameters (regardless of wettability, saturation functions, viscosities, etc.). 5500 realistic functions {Lambda }_{n} were generated using (mixed-wet and strongly water-wet) relative permeabilities, capillary pressure and mobility ratios. The variation in {Lambda }_{n} appears limited, and the generated functions span most/all relevant cases. The scaled diffusion equation was solved for each case, and recovery vs time RF was analyzed. RF could be characterized by two (case specific) parameters RFtr and lr (the correlation overlapped the 5500 curves with mean {R}^{2}=0.9989): Recovery follows exactly mathrm{RF}={T}_{n}^{0.5} before water meets the no-flow boundary (early time) but continues (late time) with marginal error until RFtr (highest recovery reached as {T}_{n}^{0.5}) in an extended early-time regime. Recovery then approaches 1, with lr quantifying the decline in imbibition rate. RFtr was 0.05 to 0.2 higher than recovery when water reached the no-flow boundary (critical time). A new scaled time formulation {T}_{n}=t/tau {T}_{mathrm{ch}} accounts for system length L and magnitude overline{D } of the unscaled diffusion coefficient via tau ={L}^{2}/overline{D }, and {T}_{mathrm{ch}} separately accounts for shape via {Lambda }_{n}. Parameters describing {Lambda }_{n} and recovery were correlated which permitted (1) predicting recovery (without solving the diffusion equation); (2) predicting diffusion coefficients explaining experimental recovery data; (3) explaining the challenging interaction between inputs such as wettability, saturation functions and viscosities with time scales, early- and late-time recovery behavior.

Effectiveness of deep eutectic solvents for light oil recovery through spontaneous imbibition

With the rise in demand for energy, comes the need to extract oil from not only primary and secondary stages, but also from tertiary recovery methods to keep up with the current market. Enhanced oil recovery (EOR) has become more prevalent within maturing reservoirs. Ionic liquids (IL) were highly regarded for chemical EOR until researchers raised concerns about their expensive cost, toxicity, and environmental impacts. Recently, deep eutectic solvents (DES) were discovered as a potential replacement for ILs due to their non-toxic nature, being biodegradable, non-flammable, and cheaper. In this study, the effectiveness of DES is investigated by observing its ability to promote oil recovery through wettability alteration. Spontaneous Imbibition tests along with emulsion and thermogravimetric tests (TGA) are used to achieve the objectives. Results indicated that both DESs can recover oil that was not recoverable using brine only. At higher temperatures, the effectiveness of DES was higher, which allowed for more oil to be imbibed out. The effect of concentration suggested that at high concentrations, DESs exhibit self-destructive properties by increasing interfacial tension (IFT), which reduced the imbibition rate and recovery factor. TGA studies indicate that the thermal stability of DESs is highly dependent on the thermal stability of their hydrogen bond donor (HBD).

Comparative study of the imbibition patterns of two types of surfactants and their residual oil morphology in low-permeability reservoirs

Forward imbibition and reverse imbibition are common imbibition modes in reservoir development. In order to understand the characteristics of recovery efficiency, sweep mode and residual oil morphology of Surfactin (reverse imbibition) and an anionic gemini surfactant (AG, forward imbibition) systems, multiscale imbibition experiments were carried out. The core and microtube experiments showed that the capillary force was dominant in the Surfactin solution and the Marangoni force was dominant in the AG solution, when the model was horizontal. In the two-dimensional pore network imbibition experiment, the recovery rate of reverse imbibition was higher than that of forward imbibition, which was consistent with the core experiment. In Surfactin solution, the dominant imbibition channel formed and swept in a fan-like pattern, however, in AG solution it failed to form a dominant imbibition channel and swept in a finger-in pattern. In the initial stage, the imbibition rate in Surfactin solution was significantly higher than that of AG solution, and its sweep efficiency was 1.5 times higher than that of AG solution. In terms of the morphology of residual oil, less oil remains on the wall during reverse imbibition, and columnar and cluster residual oil was easy to form in the channel. After long-term molecular diffusion, the Marangoni effect can effectively improve mixing between the oil and water phases, thus improving the sweep efficiency. In the case of forward imbibition, there were more residual oil films on the solid wall and punctiform residual oil was easily formed in the channel. These discoveries provide a basis for the selection of imbibition fluids or the optimization of oil recovery processes in reservoir development.

A pore-scale study on the dynamics of spontaneous imbibition for heterogeneous sandstone gas reservoirs

The underlying mechanism for spontaneous imbibition in a water–gas system plays a significant role in hydraulic fracturing in sandstone gas reservoirs. The objective of this study is to characterize the heterogeneity of low-permeability sandstones and investigate their effect on spontaneous imbibition from the perspective of the pore scale. We selected different cores with various pore structures and heterogeneity to evaluate their impact on the dynamics of spontaneous imbibition. The heterogeneities of the cores are contributed from the clay mineral distribution and are characterized through CT scans. The results show that clay minerals have higher CT numbers than the core matrix and that micropores are predominantly distributed in clay particles rather than in the core matrix. Additionally, the water imbibition rate of micropores is larger than that of the macropores, and when the porosities are similar, the water imbibition rate is increased with decreasing permeability. Moreover, the results of 1D frequency scans show that the distribution of water at different locations in the core is governed by the distribution of clay particles. These findings can help us further understand the distribution of fracturing fluids in the heterogeneous low-permeability sandstone reservoirs.

Influence of Overburden Pressure on Imbibition Behavior in Tight Sandstones Using Nuclear Magnetic Resonance Technique

Abstract Imbibition under overburden pressure can simulate the imbibition behavior in reservoir conditions during hydraulic fracturing, about which the mechanism is still unclear. This study investigated the imbibition with overburden pressure using a nuclear magnetic resonance (NMR) displacement design. The main contribution of this study is that the initial imbibition rate under confining pressure can reflect the pore connectivity of reservoirs under overburden pressure and a method for appraising the pore connectivity under confining pressure was established. The tight sandstone samples were collected from the Upper Paleozoic Taiyuan and Shihezi Formations in Ordos Basin. The Taiyuan Formation presents the apparent double-peak structure from NMR spectra, and liquid fills into small pore preferentially as a whole. When the imbibition time is on a square root scale, the cumulative imbibition height at the initial imbibition period is not stable, which deviates from the linear principle, and the initial imbibition rate ranges from 0.077 to 0.1145. The Shihezi Formation shows a dominant peak structure from NMR spectra, and the liquid has no obvious filling order as a whole. When the imbibition time is on a square root scale, the cumulative imbibition height at the initial imbibition period also deviates from the linear principle, and the initial imbibition rate ranges from 0.0641 to 0.1619.

The influence mechanism and the contribution of capillary force and gravity to recovery in spontaneous imbibition in low permeability reservoirs

Spontaneous imbibition is one of the important means to enhance oil recovery in low permeability reservoirs, and it has good field application effects. Through the interfacial tension (IFT), contact angle (CA), and adsorption experiments, the effects of SDBS surfactant on IFT and reservoir wettability were studied, and the adsorption rule of SDBS at the mineral surface was obtained. On this basis, the imbibition recovery and mechanism of cores with different permeability are studied. The study showed that in low permeability reservoir, gravity and capillary force are the main controlling factors of imbibition. In the early stage, gravity determines the recovery, because the imbibition rate is 2.75 times that dominated by capillary force. The capillary force can continue to produce oil in small pores, and the imbibition time is twice that of gravity, which determines the recovery in the late imbibition stage. Therefore, the synergistic effect of gravity and capillary force can optimize the imbibition recovery, in low permeability reservoirs. When the concentration of SDBS solution is CMC (0.1%), due to the mineral interface adsorbs, the capillary force decreases by 10.76%, and the adhesion work increases by 3.42 times, resulting in a decrease in the imbibition recovery. The imbibition driving force is different for different reservoir properties, which can be adjusted by adding a surfactant to change IFT and CA.

Seed Priming with Nanoparticles and 24-Epibrassinolide Improved Seed Germination and Enzymatic Performance of Zea mays L. in Salt-Stressed Soil

Saline stress is one of the most critical abiotic stress factors that can lessen crops' productivity. However, emerging nanotechnology, nano-fertilizers, and developing knowledge of phytochromes can potentially mitigate the negative effects of saline stress on seed germination. Therefore, the aim of this study was to investigate the effects of seed priming either with zinc oxide nanoparticles (ZnO-NPs; 50 and 100 mg L-1) or 24-epibrassinolide (EBL; 0.2 and 0.4 μM) and their combinations on maize (Zea mays L.) grains sown in salt-stressed soil (50 and 100 mM NaCl). Saline stress treatments significantly affected all germination traits and chemical analysis of seeds as well as α-amylase activity. Compared to un-primed seeds, seed priming with ZnO-NPs or EBL and their combinations significantly increased the cumulative germination percentage, germination energy, imbibition rate, increase in grain weight, K+ content, and α-amylase activity, and significantly reduced germination time, days to 50% emergence, Na+ uptake, and Na+/K+ ratio of maize sown in salt-stressed-soil (50 or 100 mM NaCl). The combination of 100 mg ZnO-NPs L-1 + 0.2 μM EBL resulted in the highest improvements for most of the studied traits of maize seeds sown in salt-stressed soil in comparison to all other individual and combined treatments.

NMR experiments on the migration characteristics of water in bedding-bearing low rank coal

Coal seam water injection is an effective technique for dust reduction in coal mines. Imbibition is an important means of water transport in coal seams and is influenced by coal bedding. The spatial distribution of water in the seepage process was obtained, and the spontaneous seepage characteristics and water transport mechanisms of coals containing different layered angles were revealed by NMR. Results show that the bedding mainly serves as the water flow channels in the imbibition. When the angle increases, the imbibition rate of adsorption pores and seepage pores in the early stage decreases. The imbibition is firstly transported to the top quickly along the bedding flow channel, 1.5h for 0° bedding coal sample, 24h for 90°, when the water reached its apex, the curve no longer changed and imbibition proceeded slowly. With the increase of bedding angle, the imbibition equilibrium time increased from 3h to 30h, up to 9 times more, the maximum imbibition rate decreases significantly, reduced from 5.64 g/h to 1.13 g/h, the flow resistance increases, and the remaining capillary force after equilibrium increases from 0.007 Pa to 5.24 Pa. When the capillary force cannot overcome the flow resistance, the imbibition reaches equilibrium.

Insights from Boltzmann transformation in solving 1D counter-current spontaneous imbibition at early and late time

Counter-current 1D spontaneous imbibition in scaled form is investigated using Boltzmann transform before and after water meets the closed boundary (early and late time). At early time the system is self-similar and only depends on position divided by square root of time. At late time it also depends on the interaction with the no-flow boundary and hence a second variable, which is set as the square root of time. Diffusion coefficients shifted to high saturations result in early time spatial saturation profiles with shorter front distance, higher average saturation within the imbibition profile and larger imbibed amount. Strongly water-wet systems have zero oil mobility at the inlet, while mixed-wet systems have finite non-zero mobility. The imbibition rate is proportional to inlet diffusion coefficient, inlet saturation gradient (regarding position divided by square root of time) and inverse square root of time. Accordingly, the saturation gradient is infinite and finite for strongly water-wet and mixed-wet systems. At early time, the profile does not change, thus recovery is proportional to square root of time. When the front meets the no-flow boundary (critical time), the saturation profile deviates from the early time profile first at the no-flow boundary, then towards the inlet. When the inlet gradient changes, imbibition rate declines faster than inverse square root of time. The interaction at the inlet and not the closed boundary, thus determines when recovery stops being proportional to square root of time and explains why such proportionality after critical time is reported. The findings were confirmed by matching experimental data. Cited as: Andersen, P. Ø. Insights from Boltzmann transformation in solving 1D counter-current spontaneous imbibition at early and late time. Advances in Geo-Energy Research, 2023, 7(3): 164-175. https://doi.org/10.46690/ager.2023.03.03

Experimental study of surfactant-enhanced spontaneous imbibition in fractured tight sandstone reservoirs: The effect of fracture distribution

Spontaneous imbibition is an important phenomenon in tight reservoirs. The existence of a large number of fractures and micro-nano pores is the key factor affecting the spontaneous imbibition of tight reservoirs. In this study, based on high-pressure mercury injection and nuclear magnetic resonance experiments, the pore distribution of tight sandstone is described. The influence of fractures, core porosity and permeability, and surfactants on the spontaneous imbibition of tight sandstone are studied by physical fracturing, interfacial tension test, wettability test and imbibition experiments. The results show that: the pore radius of tight sandstone is concentrated in 0.01–1 μm. Fractures can effectively reduce the oil drop adsorption on the core surface, enhancing the imbibition recovery of the tight sandstone with an increase of about 10%. As the number of fractures increases, the number of oil droplets adsorbed on the core surface decrease and the imbibition rate increases. The imbibition recovery increases with the increase in pore connectivity, while the imbibition rate increases with the increases in core porosity and permeability. The surfactant can improve the core water wettability and reduce the oil−water interfacial tension, reducing the adsorption of oil droplets on the core surface, and improving the core imbibition recovery with an increase of about 15%. In a word, the existence of fractures and surfactants can enhance the pore connectivity of the reservoir, reduce the adsorption of oil droplets on the core surface, and improve the imbibition rate and recovery rate of the tight oil reservoir.

Simulation of water self-imbibition in nanometer throat-pore structure filled with oil

Water self-imbibition potentially serves as a driving force for shale oil recovery due to the sizeable capillary pressure in the nanometer pores of shale. Understanding the water self-imbibition mechanism at the nanometer pore-scale helps promote shale oil recovery. In this work, we performed the direct numerical simulation using the phase-field model to study water self-imbibition dynamics in the nanometer throat-pore structure filled with oil. The effects of throat/pore morphologies (throat size, coordination number, and pore shape) and fluid properties (interfacial tension, contact angle, and viscosity) on the water imbibition dynamics were studied in detail. We distinguished two types of imbibition processes and found that the throat/pore morphologies significantly affect the final oil displacement ratio. Meanwhile, the interfacial tension and water contact angle mainly influence the imbibition rate (i.e., the oil displacement rate), while the water viscosity influences both the imbibition rate and the final oil displacement ratio. A qualitative correlation of the imbibition time and fluid properties is deduced by comparing classical theory predictions and simulation results. The quantitative deviations caused by local confinement are delineated as well.

Experimental study on unstable imbibition characteristics of fracturing fluids at high pressures and temperatures in the tight continental reservoir

Enhanced oil recovery by imbibition (IEOR) is the key technology to effectively develop tight reservoirs with “three lows” characteristics. It can be valuable for practical development to investigate the process of fracturing fluid imbibition in steady and unsteady states and quantitatively assess the impact of fracturing fluid imbibition in various pores under various circumstances. By combining NMR technology with indoor physical simulation experiments, this paper quantitatively evaluates the differences in imbibition characteristics of various pores in different conditions under high temperature and high pressure. Further research is done into how the imbibition effect is affected by permeability, pore size, imbibition duration, steady-state, and unsteady-state (pressure change). The results indicate that micropore (0.1–1 ms) imbibition efficiency is the fastest at the early stages, though it initially tends to be stable. Throughout the process of unsteady imbibition, it typically becomes stable at 48 h. However, in the steady-state imbibition process, the stabilization time lags far behind and tends to be stable at 108 h. Additionally, the mesopore (1–10 ms) has a faster imbibition rate, which is the main contributor in the middle and late stages of imbibition. As well, imbibition occurs mainly in nanopores (0.01–0.1 ms) and micropores (0.1–1 ms), followed by mesopores (1–10 ms), and finally macropores (>10 ms). For permeability <0.1 × 10−3 μm2, micropores (0.1–1 ms) are the main contributors. For the permeability of 0.1–1 × 10−3 μm2, micropores (0.1–1 ms) and mesopores (1–10 ms) are the main contributors. And for permeability >1 × 10−3 μm2, the mesopores (1–10 ms) make up the majority of the contribution. In addition, Imbibition productivity is positively associated with permeability and differential pressure in both steady and unsteady imbibition. As differential pressure and permeability increase, imbibition occurs more effectively.

Silkworm pupae derivatives as source of high value protein intended for pasta fortification

Silkworm (Bombyx mori) pupae are recognized as novel nutritionally valuable food. Their use in pasta-making was considered with the intention of repositioning spaghetti shaped pasta supplemented with silkworm derivatives (10%db ) as a valuable product in sustainable diets besides upcycling a side stream from the silk industry. The principal objective of this study was to assess the cooking quality (i.e., imbibition kinetics, cooking loss) and texture of pasta supplemented with defatted silkworm powder or with its aqueous protein extract, which enabled to reduce the content of indigestible components supplying a similar protein intake. Pasta was produced on lab-scale, dried, and tested for chemical composition, mechanical properties before and during cooking, cooking behavior in terms of hydration kinetics, starch gelatinization, and cooking quality indexes. The structural roles on pasta protein network played by silkworm powder and proteins extract were investigated. The former behaves as a structural thickener while the second provides a steric hindrance effect with consequent different cooking performances. With regards to the fortified pasta perceived quality, a high level in total color difference (ΔE) was measured (ΔE>6). However, after fortification agents' addition, pasta color became closer to that of the whole wheat pasta already known by consumers. Structure fragility increased. The energy at break of the "extract pasta" was about one-third of the control (0.849 N*mm). Silkworm powder addition led to the highest pasta optimal cooking time (376 s) and the slowest imbibition rate (0.0001 s-1 ). After fortification, pasta had an almost doubled cooking loss than control pasta (2.97±0.18g/100gdb ). PRACTICAL APPLICATION: Silkworm pupae flour can be easily applied for pasta fortification in order to increase the protein daily intake of people in an easy and practical way.

Combined imbibition system with black nanosheet and low-salinity water for improving oil recovery in tight sandstone reservoirs

Nanomaterials and low-salinity water (LSW) are two popular enhanced oil recovery (EOR) methods that have been widely studied in recent years. The former is used for in-depth conformance improvement and the latter for microscopic oil displacement (by altering the potential and contact angle). However, there are few literature on combining them to achieve synergistic effects, especially for tight sandstone reservoirs. Based on the reservoir conditions of the Jimusar Oilfield, this study investigated the oil recovery mechanism of the combined imbibition system, which was composed of black nanosheet (BN) and LSW. Its performances including decreasing interfacial tension, emulsification, and wettability alterations were evaluated. The imbibition differences between the single system of BN and LSW and the combined BN-LSW imbibition system were then compared. Results showed that the combined imbibition system had a better emulsification effect on the crude oil and could also alter the wettability of the core surface. Moreover, the combined system could increase both the imbibition rate and the ultimate oil recovery. The nuclear magnetic T2 spectrum also indicated that the addition of black nanosheets could divert more fluid into small pores and thus improve the microscopic sweep efficiency.

Dynamic development of geochemical reaction fronts during hydraulic stimulation of shale

Injection of acidic hydraulic fracture fluid (HFF) into shale formations for unconventional oil/gas production results in chemical reactions in the shale matrix that can alter fluid transport. Here, we report the results of set of experiments designed to evaluate the impact of calcite dissolution as a function of carbonate mineral content on matrix chemical reactivity and pore-space modification concomitant with imbibition. We tracked acidic HFF transport in four samples of Wolfcamp shale with calcite contents varying from 4% to 59% by monitoring the rate and spatial extent of bromide tracer transport using synchrotron-based X-ray fluorescence microprobe (XFM) imaging. Concurrently, we also carried out XFM imaging of the spatial distribution of Ca in the Wolfcamp shale cores (as a proxy of calcite distribution). Our approach thus yields a direct record of time-resolved selective ion transport resulting from the penetration of acidic HFF and the associated mineral transformations in the shale cores.We show that the variability in calcite content of Wolfcamp shale samples can directly affect the rate and spatial extent of imbibition. Although reaction of the acidic HFF with carbonates in shales enhances calcite dissolution and increases porosity, the spatial extent of calcite dissolution in the shale matrix is limited due to a rapid neutralization of pH. The relative abundance and spatial distribution of calcite control the chemical saturation state of the HFF progressing into the matrix. As a result, calcite has a major impact on the spatial extent and rate of matrix alteration and thus on HFF transport during subsurface reservoir stimulation. Consequently, increased calcite content in the shale matrix inhibits the spatial extent of the pore-volume increase and, by extension, the spatial extent and rate of imbibition.Our results thus show that the overall rates of calcite dissolution approach the rates of acidic HFF transport (i.e., Damköhler number ∼1), which could contribute to the efficiency of subsurface reservoir stimulation. A better understanding of HFF-calcite reaction rates is crucial for improving the prediction and optimization of fluid transport across HFF-shale interfaces during hydraulic fracturing.

Wettability Evaluation by Spontaneous Imbibition Measurement

The propensity of one fluid in a fluid pair to coat the surface voluntarily is known as wettability. Fluid distribution and flow behavior in porous rocks mainly controlled by wettability. Oil recovery by water flooding depend mainly on the wettability of the reservoir rock. Many methods used for wettability measurement. These methods are qualitative and quantitative. Spontaneous imbibition is one of widely used methods for quantitative wettability measurement. Direct measurement and weighing technique are two known methods for spontaneous imbibition measurement. This work presents comparison between the two aforementioned methods. Experimental measurement of spontaneous imbibition achieved on core samples from the same source. Results approved that the samples are water wet but having different tendencies, the imbibition rate related to time have variable trend in addition, ultimate water saturation in weighing method experiment are higher than that in volume measurement method. The weighing method is better than the volume measurement method.

Optimization for ultrafast capillary-driven flow in open rectangular microchannels

The Lucas−Washburn (LW) equation has been extensively used to predict the imbibition length of capillary-driven flow. Using the hydraulic diameter for non-circular cross section in the LW equation is widely accepted. Accordingly, the larger the hydraulic diameter, the higher the imbibition rate. However, the validity of the LW equation for the optimization of capillary-driven flow in open rectangular microchannels remains an open question. In this study, we propose a theoretical model to predict the imbibition rate of capillary-driven flow in open rectangular microchannels. To validate the model, we conducted a series of experiments on spontaneous capillary-driven flow of water in open rectangular Si microchannels. We fabricated Si microchannels with hydraulic diameters ranging from 18 to 375 µm to investigate the dependence of the imbibition rate on the hydraulic diameter. The proposed model was consistent with the experimental results. In the case of microchannels with a fixed height, a plot of the measured imbibition rate against the hydraulic diameter was well fitted by a downward-opening parabolic curve, indicating that the imbibition rate had an optimal value at the aspect ratio (width to height) of two. For a given channel width, the imbibition rate increased with the hydraulic diameter, and it leveled off at a large hydraulic diameter for aspect ratios below 0.5. An ultrafast imbibition time of 1.97 s over an entire length of 70 mm was achieved, corresponding to the optimal imbibition rates of 40 mm/s at imbibition length x1 = 34 mm and 19 mm/s at x2 = 68 mm among the experimental cases.

Experimental study of effective compounds in a smart water injection process

The process of smart water injection into carbonate reservoirs has always faced many challenges. This study attempted to investigate this issue by examining two effective factors active ionic compounds in brine and active compounds in the oil phase. The potential for the reaction among three phases’ oil, rock, and brine in changing wettability requires the presence of active ionic compounds in the brine water and active compounds in the oil. These compounds in optimal concentrations are the driving force of the wettability alteration process. In the first step, the contact angle and the spontaneous imbibition process were performed on the outcrop samples and the limestone core to investigate the effect of the active compounds of smart water. The efficiency of calcium and divalent magnesium cations mainly depends on the sulfate ion concentration. However, reservoir physical condition and the presence of other effective compounds in the reactions network can be helpful in the determination of the essential active ions in the reaction. Finally, the optimal concentrations of these three ions lead to the formation of a stable water film and a change in the wettability of the rock, which leads to an increase in oil recovery. In this regard, cations in the presence of sulfate ions as much as the minimum concentration in seawater can have a positive function and have an acceptable efficiency compared to increased concentrations of sulfate ions in seawater. The cores were saturated with two oil samples for further investigation, and again, two tests of measuring contact angle and spontaneous imbibition were performed. The difference between imbibition rate and ultimate recovery illustrates that the carboxylic acid functional group in the original crude oil structure can facilitate displacement compared to oil-free acid components. Therefore, acidic components in crude oil affect the wettability alteration through electrostatic interaction with surface minerals and brine. Active components can act as a critical indicator in smart water injection processes.

Pre-Germinative Treatments and Morphophysiological Traits in Enterolobium cyclocarpum and Piscidia piscipula (Fabaceae) from the Yucatan Peninsula, Mexico.

Enterolobium cyclocarpum and Piscidia piscipula are two important tree Fabaceae species distributed from the Yucatan Peninsula, Mexico. Our aims were focused on the E. cyclocarpum and P. piscipula seeds for: (1) to examine the seed permeability and imbibition rate, (2) to evaluate the effect of seed pre-germinative treatments, and (3) to characterize the structures involved on the presence of physical dormancy (PY). We used fresh seeds to determine seed permeability and imbibition rate, seed viability by means of tetrazolium test, furthermore, we applied mechanical scarification and boiler shocks for 5 s, 10 s and 15 s treatments. Morphological characterization of the seed coat was by Scanning Electron Microscope (SEM). Seed viability in E. cyclocarpum and P. piscipula were 100% and 96%, respectively. Seed permeability and imbibition rate in E. cyclocarpum were low. The highest germination in E. cyclocarpum was in the mechanical scarification (92%), while in P. piscipula, this parameter was in the 10 s boiling water treatment (76.0%). The presence of PY was confirmed in both species because they showed low seed permeability, and imbibition rate; furthermore, exhibited macrosclereids cells. The present research seeks to promote the sustainable use of E. cyclocarpum and P. piscipula.