The Effect Of Residual Oil On Deep-Bed Filtration Of Particles In Injection Water

2007 ◽  
Author(s):  
Peter K. Currie ◽  
Mohammad A.J. Ali ◽  
Mohammad J. Salman
Keyword(s):  
Residual Oil ◽  
Deep Bed Filtration ◽  
Injection Water

The Effect of Residual Oil on Deep-Bed Filtration of Particles in Injection Water

2009 ◽  
Vol 24 (01) ◽  
pp. 117-123 ◽  
Author(s):  
Mohammad A.J. Ali ◽  
Peter K. Currie ◽  
Mohammad J. Salman
Keyword(s):  
Residual Oil ◽  
Deep Bed Filtration ◽  
Injection Water

scholarly journals Simulation of Surfactant Oil Recovery Processes and the Role of Phase Behaviour Parameters

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 983 ◽  
Author(s):  
Pablo Druetta ◽  
Francesco Picchioni
Keyword(s):  
Oil Recovery ◽  
Phase Behaviour ◽  
Residual Oil ◽  
Two Phase ◽  
Oil Saturation ◽  
Recovery Processes ◽  
Fluid Properties ◽  
Injection Water ◽  
Finitedifference Method

Chemical Enhanced Oil Recovery (cEOR) processes comprise a number of techniques whichmodify the rock/fluid properties in order to mobilize the remaining oil. Among these, surfactantflooding is one of the most used and well-known processes; it is mainly used to decrease the interfacialenergy between the phases and thus lowering the residual oil saturation. A novel two-dimensionalflooding simulator is presented for a four-component (water, petroleum, surfactant, salt), two-phase(aqueous, oleous) model in porous media. The system is then solved using a second-order finitedifference method with the IMPEC (IMplicit Pressure and Explicit Concentration) scheme. The oilrecovery efficiency evidenced a strong dependency on the chemical component properties and itsphase behaviour. In order to accurately model the latter, the simulator uses and improves a simplifiedternary diagram, introducing the dependence of the partition coefficient on the salt concentration.Results showed that the surfactant partitioning between the phases is the most important parameterduring the EOR process. Moreover, the presence of salt affects this partitioning coefficient, modifyingconsiderably the sweeping efficiency. Therefore, the control of the salinity in the injection water isdeemed fundamental for the success of EOR operations with surfactants.

Produced Water Quality: The Effects of Different Separation Methods for Water and Chemical Floods

2021 ◽  
Author(s):  
Jawaher Almorihil ◽  
Aurélie Mouret ◽  
Isabelle Hénaut ◽  
Vincent Mirallès ◽  
Abdulkareem AlSofi
Keyword(s):  
Water Quality ◽  
Oil Content ◽  
Produced Water ◽  
Light Transmission ◽  
Formation Damage ◽  
Residual Oil ◽  
Separation Plant ◽  
Deep Bed Filtration ◽  
Separation Techniques ◽  
Gravity Settling

Abstract Gravity settling represents the main oil-water separation mechanism. Many separation plants rely only on gravity settling with the aid of demulsifiers (direct or reverse breakers) and other chemicals such as water clarifiers if they are required. Yet, other complementary separation methods exist including filtration, flotation, and centrifugation. In terms of results and more specifically with respect to the separated produced-water, the main threshold on its quality is the dispersed oil content. Even with zero discharge and reinjection into hydrocarbon formations, the presence of residual oil in the aqueous phase represents a concern. High oil content results into formation damage and losses in injectivity which necessitates formation stimulations and hence additional operational expenses. In this work, we investigated the effects of different separation techniques on separated water quality. In addition, we studied the impact of enhanced oil recovery (EOR) chemicals on the different separation techniques in terms of efficiency and water quality. Based on the results, we identified potential improvements to the existing separation process. We used synthetic well-characterized emulsions. The emulsions were prepared at the forecast water: oil ratio using dead crude oil and synthetic representative brines with or without the EOR chemicals. To clearly delineate and distinguish the effectiveness of different separation methods, we exacerbated the conditions by preparing very tight emulsions compared with what is observed on site. With that, we investigated three separation techniques: gravity settling, centrifugation, and filtration. First, we used Jar Tests to study gravity settling, then a benchtop centrifuge at two speeds to evaluate centrifugation potential. Finally, for filtration, we tested two options: membrane and deep-bed filtrations. Concerning the water quality, we performed solvent extraction followed by UV analyses to measure the residual oil content as well as light transmission measurements in order to compare the efficiency of different separation methods. The results of analyses suggest that gravity settling was not efficient in removing oil droplets from water. No separation occurred after 20 minutes in every tested condition. However, note that investigated conditions were severe, tighter emulsions are more difficult to separate compared to those currently observed in the actual separation plant. On the other hand, centrifugation significantly improved light transmission through the separated water. Accordingly, we can conclude that the water quality was largely improved by centrifugation even in the presence of EOR chemicals. In terms of filtration, very good water quality was obtained after membrane filtration. However, significant fouling was observed. In the presence of EOR chemicals, filtration lost its effectiveness due to the low interfacial tension with surfactants and water quality became poor. With deep-bed filtration, produced water quality remained good and fouling was no longer observed. However, the benefits from media filtration were annihilated by the presence of EOR chemicals. Based on these results and at least for our case study, we conclude that centrifugation and deep-bed filtration techniques can significantly improve quality of the separated and eventually reinjected water. In terms of the effects of EOR chemicals, the performance of centrifugation is reduced while filtrations are largely impaired by the presence of EOR chemicals. Thereby, integration of any of the two methods in the separation plant will lead to more efficient produced-water reinjection, eliminating formation damage and frequent stimulations. Yet, it is important to note that economics should be further assessed.

Produced Water Quality: the Effects of Different Separation Methods

2021 ◽  
Author(s):  
Jawaher Almorihil ◽  
Aurélie Mouret ◽  
Isabelle Hénaut ◽  
Vincent Mirallés ◽  
Abdulkareem AlSofi
Keyword(s):  
Water Quality ◽  
Oil Content ◽  
Produced Water ◽  
Light Transmission ◽  
Formation Damage ◽  
Residual Oil ◽  
Separation Plant ◽  
Deep Bed Filtration ◽  
Separation Techniques ◽  
Gravity Settling

Abstract Gravity settling represents the main oil-water separation mechanism. Many separation plants rely only on gravity settling with the aid of demulsifiers (direct or reverse breakers) and others chemicals such as water clarifiers if they are required. Yet, other complementary separation methods exist including filtration, flotation, and centrifugation. In terms of results and more specifically with respect to the separated produced-water, the main threshold on its quality is the dispersed oil content. Even with zero discharge and reinjection into hydrocarbon formations, the presence of residual oil in the aqueous phase represents a concern. High oil content results into formation damage and losses in injectivity which necessitates formation stimulations and hence additional operational expenses. In this work, we investigated the effects of different separation techniques on separated water quality. Based on the results, we identified potential improvements to the existing separation process. We used synthetic well-characterized emulsions. The emulsions were prepared at the forecast water:oil ratio using dead crude oil and synthetic representative brine. To clearly delineate and distinguish the effectiveness of different separation methods, we exacerbated the conditions by preparing very tight emulsions compared with what is observed on site. With that, we investigated three separation techniques: gravity settling, centrifugation, and filtration. First, we used jar tests to study gravity settling, then a benchtop centrifuge at two speeds to evaluate centrifugation potential. Finally, for filtration, we tested two options: membrane and deep-bed filtrations. Concerning the water quality, we performed solvent extraction followed by UV analyses to measure the residual oil content as well as light transmission measurements in order to compare the efficiency of different separation methods. The results of analyses suggest that gravity settling was not efficient in removing oil droplets from water. No separation occurred after 20 minutes in every tested condition. However, note that investigated conditions were severe, tighter emulsions are more difficult to separate compared to those currently observed in the actual separation plant. On the other hand, centrifugation significantly improved light transmission through the separated water. Accordingly, we can conclude that the water quality was largely improved by centrifugation. In terms of filtration, very good water quality was obtained after membrane filtration. However, significant fouling was observed. With deep-bed filtration, produced water quality remained good and fouling was no longer observed. On the basis of those results, we conclude that for our case study, centrifugation and deep-bed filtration techniques can significantly improve quality of the separated and eventually reinjected water. Thereby, integration of any of the two methods in the separation plant will lead to more efficient produced-water reinjection, eliminating formation damage and frequent stimulations. Yet, it is important to note that economics should be further assessed.

A Model for Interfacial Activity of Acidic Crude Oil/Caustic Systems for Alkaline Flooding

1983 ◽  
Vol 23 (04) ◽  
pp. 602-612 ◽  
Author(s):  
T.S. Ramakrishnan ◽  
D.T. Wasan
Keyword(s):  
Crude Oil ◽  
Equilibrium Constants ◽  
Active Species ◽  
Acid Number ◽  
Residual Oil ◽  
Oil Saturation ◽  
Interfacial Activity ◽  
Batch System ◽  
Injection Water ◽  
System Chemistry

Abstract The interaction of the alkali in floodwater and the acids in reservoir crude results in the in-situ formation of surfactants, which are responsible for the lowering of interfacial tension (IFT) in caustic flooding. The extent to which IFT is lowered depends on the specific properties of the crude oil and the injection water. Therefore, it is properties of the crude oil and the injection water. Therefore, it is important to establish the relationship between IFT and the essential chemical properties of the acidic oil and the floodwater. This paper presents such a relationship. presents such a relationship. In this discussion, the adsorption and the desorption of the active species at the interface are modeled as ionic processes using the Gouy-Chapman theory of the diffuse double layer. The interfacial potentials calculated using this model show a fair agreement with the potentials calculated using this model show a fair agreement with the experimentally measured trend of electrophoretic mobility. Also, the model rationalizes the experimentally observed effects of alkali concentration, salinity, and the oleic- to aqueous-phase ratio on IFT. We conclude that the acid number of the crude oil may not correlate directly with interfacial activity. Even in cases of low-acid-number crudes, significant interfacial activity could be obtained because of highly hydrophobic active species in the crude. Introduction IFT in acidic crude/alkali systems plays an important role in EOR with alkaline agents. The extent-and probably the mechanism-of oil recovery is highly dependent on the degree to which IFT is lowered in such systems. Because it is possible to estimate the residual oil saturation from capillary number, and hence the IFT through a suitable displacement model, there is a necessity for quantitative evaluation of IFT in an alkaline flooding process. Although it is widely accepted that surfactants are generated by reaction in caustic flooding of acidic crude reservoirs, there have been few attempts to develop a chemistry and relate it to the IFT attained in these systems. A relationship between equilibrium IFT and NaOH concentration (restricted here to caustic) in a batch system permits comparison with experimental data, and hence evaluation of system parameters such as equilibrium constants. Also, from these parameters, an parameters such as equilibrium constants. Also, from these parameters, an equilibrium flow model can be solved for the concentration of chemical agents in place in caustic flooding. The IFT and hence the residual oil saturation can then be calculated in a flow process, on the basis of the batch relationship. This study, by rationalizing the observations of IFT in acidic crude/caustic systems, permits evaluation of the equilibrium constants and the other necessary parameters. The model also reveals the dependence of interfacial potential on variables such as NaOH and NaCl concentrations. Model Description The rationalization of the interfacial activity between the acidic crude oil and caustic solution is based on a simple system chemistry. The proposed system chemistry has been used to solve for the interfacially proposed system chemistry has been used to solve for the interfacially active species in a batch system. Considering adsorption and desorption kinetics at the interface, along with a suitable theoretical description of the electrical double layer, we derived the adsorption isotherm for the active species. The interfacial activity (i.e., the reduction in IFT of the system) was then directly calculated by the Gibbs equation for adsorption at the interface. An alternative method using an equivalent equation of state (EOS) is also presented. To keep mathematics tractable and the physics simple, the formation of micelles is not considered. Only an equilibrium study is conducted here, and it is applicable primarily to an equilibrium flow model. SPEJ p. 602

Planning And Development Of Polymer Assisted Surfactant Flooding For The Gullfaks Field, Norway

1998 ◽  
Vol 1 (02) ◽  
pp. 161-168 ◽  
Author(s):  
T. Maldal ◽  
E. Gilje ◽  
R. Kristensen ◽  
T. Karstad ◽  
A. Nordbotten ◽  
...  
Keyword(s):  
Oil Recovery ◽  
Oil Production ◽  
Current Drive ◽  
Mobility Control ◽  
Residual Oil ◽  
Surfactant Flooding ◽  
Oil Viscosity ◽  
Full Field ◽  
The North ◽  
Injection Water

Abstract This paper presents parts of the work performed in order to develop and qualify a Polymer Assisted Surfactant Flooding (PASF) system for economical use in the Gullfaks Field. The paper addresses experimental work done in the laboratory, numerical simulation of PASF, and the evaluation of the potential for PASF in full field scale. The experimental part comprises core flooding experiments at different temperatures, pressures, and gas-oil ratios in order to optimise the PASF system for the Gullfaks Brent formation conditions. The surfactant in the PASF system is a branched sulphonate (5000 ppm) and xanthan (500 ppm). The surfactant-polymer slug is followed by a slug of xanthan (500 ppm) for mobility control. No cosolvent is used. In coreflood experiments more than 70 percent of the waterflood residual oil was recovered. By using reservoir simulation a suitable pilot area was found in the Brent reservoir. Additional results from simulations were the amount of chemicals, the time needed for the pilot test, and additional oil recovery. Much effort was put into estimating the full field PASF potential. Firstly, the areas of the field where PASF possibly could be used were selected. Key factors were existing and planned well locations, production data, and long term production forecasts. Then the amount of chemicals needed and the expected technical efficiency for each area were calculated. To verify these calculations, an area of the field containing two possible injection wells, and three producers, was selected for a simulation study. This area was considered as the most promising area for PASF. The main conclusion from this work is that, with the present crude oil price and chemical costs, the PASF process is not economical attractive for use in the Gullfaks field, mainly because the residual oil was considerable lower than believed at project start. Introduction The Gullfaks field is located in the north-eastern part of block 34/10 in the Norwegian sector of the North Sea. The oil production started in December 1986 and the cumulative oil production to date is 168 mill. Sm3 or 59 % of recoverable reserves. Water injection is the current drive mechanism, aiming at maintaining reservoir pressure above the bubble point. At the project start in 1989, the Gullfaks field was from a technical standpoint a prime target for enhanced oil recovery . The residual oil saturation after waterflooding was believed to be about 0.35, which indicated a high technical potential for surfactant flooding. Most of the reservoir characteristics are favourable for PASF, i. e. multidarcy sands, low oil viscosity (1.5 cP), relatively low reservoir temperature (70 C) and low salinity of the formation water (42000 ppm) and moderate low clay content (5-10 %). A single well injection test with surfactant alone was performed during the first half of 1992. The surfactant was successfully injected without any special treatment of the injection water, and the test confirmed that residual oil was mobilised by the surfactant. Exxon conducted a series of five pilot tests in the Loudon field from 1980 to 1989. The test sizes ranged from a single pattern of 2800 m2 to multi-pattern tests with pilot areas of 161600 m2 and 323200 m2 areas, respectively. For the 2800 m2 pilot, recovery was 68 % of the waterflood residual oil. In the larger multi-pattern floods, oil recovery dropped to 26.9 % in the 161600 m2 and 33.4 % in the 323200 m2 project. The tests showed that the use of polymer in the injection water is crucial for obtaining a successful surfactant flooding. An other observation in these field tests was that the surfactant retention was less than half of that measured in conventional laboratory coreflood experiments. This was explained by a change of wettability from aerobic, oxidising conditions, in the laboratory, to the anaerobic, reducing conditions, in the reservoir.

Numerical Simulation Research on Locations Optimization of Horizontal Well to Exploit Remaining Oil of Lateral Accretion Interbed after Polymerflooding

2013 ◽  
Vol 318 ◽  
pp. 460-464
Author(s):  
Tao Ping Chen ◽  
Chao Jiang ◽  
Li Li Wang
Keyword(s):  
Numerical Simulation ◽  
Horizontal Well ◽  
Conceptual Models ◽  
Vertical Direction ◽  
Simulation Software ◽  
Residual Oil ◽  
Simulation Research ◽  
Vertical Well ◽  
Remaining Oil ◽  
Injection Water

Conceptual models of lateral accretion interbed (the point bar lateral sandbody model contains three lateral accretion interbed .And the lateral accretion interbeds extends to two-thirds of reservoir thickness)is builded making use of numerical simulation software Eclipse. The effect of injection water on water drive recovery is analysised. The location of remaining oil enrichment is also determined. Horizontal well is placed in remaining oil enrichment and its vertical direction and horizontal hole section are optimization. Horizontal well and vertical well are combined to exploit residual oil. Results indicates that: Injectiong water in the direction of lateral accretion interbed can obtain higher water drive recovery than in the opposite direction. The closer to top the horizontal well is , the greater recovery enhancement values is.Horizontal hole section starts from the location of four-fifths of lateral sandbody I left and terminats nine-tenths of lateral sandbody III, where the recovery is highest. Horizontal well is placed after vertiacal well injecting polymer in which recovery can increase 9.8%. According to numerical simulation optimization results, we have made a physical model with lateral accretion interbeds to do experiments. Numerical simulation results agree with experimental results. Hence horizontal and vertical well uinting together can exploit the remaining oil of lateral accretion interbed effectively .

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