Low salinity chase waterfloods improve performance of criiiacetate hpam gel in fractured cores. The concept of surfactant flooding has long been recognized as a promising supplement to waterbased enhanced oil recovery methods. The application of low salinity water in combination with other established eor processes e. Special issue on low salinity water flooding for enhanced. Clearly, mixing of low salinity polymer solution with high salinity brine injected during secondary flooding did not affect polymer viscosity because of a low salinity buffer that will form between the two fluids due to polymer adsorption and the high salinity brine will be stably displaced by low salinity polymer vermolen et al. The aforementioned cases are applied under different wetting conditions. Hybrid injection of low salinity water and polymer can be. In this paper a five spot well patterns is used to study low salinity, polymer, conventional, waterflooding and the combination of polymer flooding and lswf. Low salinity waterflood in combination with surfactantpolymer. Spe176315ms 3d simulation of low salinity, polymer. Oil recovery techniques primary depletion water flooding water drivepattern injection low salinity waterflood bp smart waterflood armaco ion management waterflood exxon low tensionlow salinity waterflood the u.
Mapping of fines assisted low salinity water flooding on polymer flooding model as conceived earlier, this technique of controlling water encroachment in edge water drive reservoirs by mobilizing in situ fines present in the reservoir is similar to other conventional techniques. Displacement efficiency for lowsalinity polymer flooding. In low salinity polymer flooding lsp, the source brine is first treated to achieve significantly lower salinities compared to the formation brine. Spotlight on the new natural surfactant flooding in. A simple benefit analysis suggested that reduced injectivity may be a greater limitation for polymer flooding of viscous oils than the cost of chemicals. Polymer viscosity degrades in reservoirs with highsalinity brines, so it is advantageous to inject lowsalinity water as a preflush. Polymer flooding can significantly improve sweep and delay breakthrough of injected water, thereby increasing oil recovery. Reduced injectivity may be a greater concern for polymer flood application than the chemical cost of viscous polymer. In standard water flooding oil recovery, water, typically seawater is injected on a macroscopic scale into the oilcarrying rock layers to push the oil from these injection wells towards a. Several laboratory studies demonstrated the potential of low salinity water flooding to improve oil recovery where the core flood experiments showed increase in. Combined low salinity brine injection and surfactant. Polymer and low salinity flooding can improve the oil recovery from both sandstone and carbonate reservoirs.
The use of low salinity polymer solution in polymer flooding has significant benefits because considerably lower amount of polymer is required to make the solution of a target viscosity. Lsp flood may also benefit from the low salinity effect. The extra oil production was total observed in some of the cores, but seems no to be reproduced in all parallel experiments. The polymer used is hpam and the concentration of polymer has been very low. Economic analysis of low salinity polymer flooding. Hence, lsp injection may be an option for hths reservoirs and can enlarge the polymer operating window. The makeup brine for the polymer solution can come from natural sources such as seawater or an aquifer. Index terms low salinity water flooding, oil recovery, secondary recovery, tertiary recovery.
Finally, the enhancement of polymer flooding by using lowsalinity water. Even though, new polymers can resist harsh conditions. Pdf delayed arrival of the oil bank and reduced injectivity are risks which are commonly associated with low salinity polymer lsp flooding. Polymer flooding consists of injecting polymeraugmented water into a. Enhanced oil recovery eor by combined low salinity water. The combined processes involve dampening capillarity to avoid trapping of mobilized oil, reducing residual oil saturation sor, and altering frontal stability and sweep. This special issue seeks high quality submissions, which are devoted to recent research advancements, development and application of low salinity water flooding processes for enhanced oil recovery in both sandstone and carbonate reservoirs including but not limited to the following. Core flood experiments were also conducted by hashmet et al. Participants will learn the methods of polymer flooding, including reservoir screening, laboratory tests, pilot phase, and field implementation. Low salinity polymer flooding lspf is a promising enhanced oil recovery eor method with a synergetic effect of combining the polymer injection and low salinity water injection methods. Assess polymer injectivity into the schrader bluff formations for various polymers at various concentrations. Low salinity waterflooding fundamentals and case studies. Lowsalinity polymer flooding is a promising eor method for carbonate reservoirs. For existing eor polymers, viscosity increases roughly with the square of polymer concentrationa fact that aids the economics for polymer flooding of viscous oils.
Several coreflood experiments were conducted to study the efficiency of low salinity water flooding and low salinity polymer flooding in mixedwet berea sandstone cores. Low salinity polymer flooding can also increase oil recovery by lowering residual oil saturation and achieve faster oil recovery. Low salinity waterflooding is a recent development in the field of eor and polymer flooding is a conventional eor technique practiced for many decades. Optimization study of a novel water ionic technology for. Low salinity polymer flooding can also increase oil recovery by lowering residual oil saturation and achieve faster oil recovery by improving sweep efficiency. Polymer flooding is a mature eor technique, which is successfully. Experimental investigation of polymer flooding with lowsalinity. Efficiency of low salinity polymer flooding in sandstone cores.
Having low recovery factor for carbonate settings, various eor eor techniques such as low salinity water injection 4,5, surfactant flooding 6, polymersurfactant sp injection 7, alkaline. Chemical mechanism of low salinity water flooding i n. Assess and optimize injection conformance along horizontal wellbore and reservoir sweep between horizontal injectors and producers. Low salinity flooding of reservoir cores including cbm water, chemical analysis and inline monitoring of ph and conductivity of effluent brine behrooz raeesi, ph. Potential for polymer flooding reservoirs with viscous oils.
Alternatively, the produced water can be reinjected pwri. Also as table 5 shows, secondary mode low salinity polymer flooding core s6s7 gives considerably higher oil recovery compared to tertiary low salinity polymer flooding core s3s4. Combining these methods is of interest because they can improve both macroscopic and microscopic sweep efficiency, and the required polymer volume becomes less when mixed with low salinity brine, which has a. Lowsalinity water 500ppm parts per million tds with polymer was. As a result, a reduced polymer dosage is required in lowsalinity water to achieve injection viscosities similar to those of highsalinity water raney et al. In recent years, core displacement experiments performed on clastic rock samples using low salinity brine as injection fluid have proven to give a moderate increase in crude oil recovery. Low salinity waterflood and low salinity polymer injection. Flooding experiments have been made to investigating the effects of low salinity brine injection and the combined injection of low salinity surfactant and low salinity polymer solutions.
The papers published on lowsalinity recovery are mostly based on laboratory displacement experiments, and there are therefore few examples of reservoir modeling of lowsalinity water flooding. The change in injection brine viscosity is therefore very small, but the impact on oil recovery is significant. Valderhaug 20 reported an incremental 10% extra recovery when polymer was added to lsw in tertiary injection mode. These experiments have shown a large increase in oil recovery compared to traditional, high salinity brine injection. Accordingly, low salinity water flooding eor methods have great potential for enhanced oil recovery in the future. Lowsalinity water also has a synergistic effect on polymer floods that results in. The recovery of crude oil from geological reservoirs is a complex process that bridges multiple length scales. We have in this study made core flood experiments to study the combined effect of low salinity and polymer injection the polymer used is hpam and the.
The first set of data relates to the core flooding experiment that was carried out by shiran and skauge at the university of bergen 10. The endpoint mobility ratio assumes a pluglike displacement between the oil phase, at connatewater saturation before the flood front, and the water phase at. Oil recovery by lowsalinity polymer flooding in carbonate oil reservoirs. The use of polymer in polymergel conformance will also be discussed. Pdf experimental investigation of polymer flooding with. Permadi 3 and shabrina sri riswati 1 1 department of energy and mineral resources engineering, sejong university, seoul 05006, korea. On the other hand, in a lower salinity environment, the mechanical shear degradation zaitoun et al.
The results also show the benefit of secondary low salinity flooding in combination with polymer injection compared to. To maximize eor efficiency, it is essential to design the compositions of low salinity water appropriately while considering polymer properties. This paper presents a new hybrid eor process where the. Low salinity waterflooding has received increasing attention however, the increased oil recovery by low salinity is in most cases very limited combining low salinity with other eor methods has been our focus in recent years. Lowsalinity polymer flooding lspf is a promising enhanced oil recovery eor method with a synergetic effect of combining the polymer injection and lowsalinity water injection methods. Evaluate the water salinity effect on the performance of polymer flooding and gel treatments. Several mechanisms for lowsalinity injection have been proposed, but scientists have not yet reached a consensus regarding the main mechanisms. Novel insights into porescale dynamics of wettability alteration.
The paper concludes that lowsalinity polymer flooding can significantly. Combining low salinity brine with surfactants and polymers yielded varying production. Oil recovery by lowsalinity polymer flooding in carbonate. Resistivity measurements and polymer flooding of sandpacks. Improving polymer flooding technical feasibility and economics by using lowsalinity makeup brine. Designing composition of lowsalinity water appropriately with polymer. Optimal design of alkalinesurfactantpolymer flooding. Low salinity as new technique of enhanced oil recovery. Low salinity waterflooding is a relatively new enhanced oil recovery eor technology in which the ionic strength and composition of injection. Recent research has made a combined low salinity and surfactantpolymer flooding a way of boosting oil recovery and improve the economy of this eor process source. Wet sandstone cores, energy and fuels, 2010, 24, 355559. To maximize eor efficiency, it is essential to design the compositions of lowsalinity water appropriately while considering polymer properties.
Simulation study of salinity effect on polymer flooding in. Mechanistic modeling of combined low salinity waterflood. Low salinity waterflood in combination with surfactantpolymer core. Single phase coreflood experiments were performed, where low and high salinity polymer hsp solutions, i. During a polymer flood, polymer retention can have a major impact on the rate of polymer propagation through a reservoir, andconsequently, on oil recovery. Experimental data in this study, two data sets have been used for simulation. Synergism between different enhanced oil recovery eor methods has always been a subject of paramount interest for oil industries as it led to the development of many successful eor methods in the past. Several laboratory studies demonstrated the potential of low salinity waterflooding to improve oil recovery where the core flood experiments showed increase in.
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