It was originally proposed as a method to improve the sweep efficiency of gas by using water to control the mobility ratio and to stabilize the front caudle and dyes, 1958. The list of acronyms and abbreviations related to wag water alternating gas. The application of this technology remains limited due to the complexity of the wag injection process which requires timeconsuming indepth technical. Water alternating enriched gas injection to enhance oil. Multiphase flow and hysteresis phenomena in oil recovery. Wateralternatinggas saturation monitoring in a single. We thus studied the efficiency of each injection option and predicted the associated storage capacities and co 2. The application of this technology remains limited due to the complexity of the wag injection process which requires timeconsuming indepth. Optimization of the water alternating gas injection. Mobility control is a major concern in gas flooding process, and wateralternatinggas injection wag for enhanced oil recovery eor, which can be improved by simultaneous injection of chemicals. Dynamic flow simulation to study flow assurance challenges in water alternating gas wag wells abstract wateralternatinggas wag is an enhanced oil recovery process which is being widely practiced in the oil fields to increase the extent of the reservoir contacted by the displacing fluids, the gas is generally injected intermittently with water. In this paper, optimization of miscible co2 wateralternatinggas co2wag injection in the bakken formation is experimentally studied. However, still there is an insufficient understanding of these processes in a microlevel and the need for comparative work is inevitable. Wateralternatinggas wag injection a novel eor technique.
Co2 water alternating injection has greater popularity nowadays 11,12. First, a slimtube apparatus was used to measure the minimum miscibility pressure mmp of a co2crude oil system mmp 22. To enhance oil recovery, both water and gas are injected in the reservoirs in water alternating gas wag cycles. Water flooding and gas injection are two widely used improved oil recovery techniques that can be applied individually or combined as water alternating gas wag or simultaneous gas and water swag injection. Oil recovery performance and co2 storage potential of co2. Pdf in reservoirs with high heterogeneities, the wag injections have been applied with success instead of secondary recovery technique. Wed like to understand how you use our websites in order to improve them. Wag injection is defined as the alternate injection of water to gas ratios of 0. Effect of surfactant on three phase relative permeability in.
Wateralternatinggas wag injection a novel eor technique for mature light oil fields a laboratory investigation for gs5c sand of gandhar field. The process exploits the microscopic displacement advantages. Enhancement of co2 trapping efficiency in heterogeneous. Wag injection is defined as the alternate injection of watertogas ratios of 0.
Laboratory data on wag and swag injections for nonwaterwet systems are very limited especially for nearmiscible very. Gas injection is the second largest enhanced oil recovery process, next only to thermal processes used in heavy oil fields. It is known that using the water alternating gas wag injection some of that oil can be produced. Feasibility concerns and technical challenges, such as low injectivity, formation damage, and. Water alternating gas wag water alternating gas involves gas injection followed by water injection gas injection increases displacement efficiency water injection increases sweep efficiency 5. Critical parameters affecting water alternating gas wag. Optimization of a water alternating gas injection compositional fluid flow simulation with simultaneous water alternating gas injection optimization on the upscaled synthetic reservoir cerenai the main objective of this work is to devise a production strategy, on a brazilian presalt. Srivastava, laxminarayan mahli, irs, ongc summary it is an established fact that substantial amount of oil usually remains in a reservoir after primary and secondary processes. Wag process is used to improve the efficiency of gas flooding by controlling gas mobility. Water alternating gas wag injection process is a proven eor technology that has been successfully deployed in many fields around the globe. Optimization of hydrocarbon water alternating gas in the. Second, the vanishing interfacial tension technique is applied to determine the minimum miscibility pressure of the bakken light crude oil and co2 at the actual. In this study, oil recovery performance and carbon dioxide co2 storage potential of a co2 wateralternatinggas co2wag injection after continuous co2 injection process for multilayer formation were experimentally determined under immiscible and miscible conditions. Water alternating gas eor process wag mobility oil and gas.
Despite its proven success, wag application growth has been. Published on december 21, 2015 december 21, 2015 261 likes 22 comments. This is accomplished by the study and application of various methods. Pdf experimental investigation of miscible and immiscible. A specific type of gdr application is the immiscible wateralternatinggas iwag displacement process. Water alternating gas wag injection are improved oil recovery methods that involve threephase fluid flow. Fundamentals of carbon dioxideenhanced oil recovery eora. The most important criterion for miscibility determination is the minimum miscibility pressure mmp. Swag is an enhanced oil recovery process in which gas is mixed with water outside the well and the mixture is then injected as a two phase mixture in the well or. Mobility control is a major concern in gas flooding process, and water alternating gas injection wag for enhanced oil recovery eor, which can be improved by simultaneous injection of chemicals. Water alternating gas injection process wag is a tertiary oil recovery technique commonly used to enhance the displacement efficiency of the residual oil which. May 20, 2019 water alternating gas wag injection process is a proven eor technology that has been successfully deployed in many fields around the globe. Water alternating gas wag injection process is a proven enhanced oil recovery eor technology with many successful field applications around the world.
Haynesb afaculty of engineering and applied science, memorial university of newfoundland, st. It is known that using the wateralternatinggas wag injection some of that oil can be produced. Also, availability of hydrocarbon or co2 gases in the field makes it attractive for gasbased enhanced oil recovery eor methods such as. Intelligent wateralternatinggas process using downhole control valve wagcv. The effect of hysteresis and cycle dependent relative permeability on wag and foam injections incorporating a new threephase hysteresis model has been investigated. Intelligent water alternating gas process using downhole control valve wagcv. The wag scheme is a combination of two traditional techniques of improved hydrocarbon recovery. Co2wateralternating injection can e ectively enlarge swept volume and oil displacement e ciency. Wellbore stability model based on iterative coupling.
Wateralternatinggas injection can potentially lead to an improved oil recovery and simultaneous cycles of alternating flooding improves the oil recovery to a greater extend. The main objectives of this study are to determine the most suitable type of gas for a water alternating gas wag injection scheme, the wag cycle time, and gas injection rate to increase oil production rate and recovery from the san francisco field, colombia. Multiphase flow and hysteresis phenomena in oil recovery by. As for recent cases, the study of fluid mobility control and sweep efficiency in.
The gas phase modifications include the following alternatives for the gas phase. The main objectives of this study are to determine the most suitable type of gas for a wateralternatinggas wag injection scheme, the wag cycle time, and gas injection rate to increase oil production rate and recovery from the san francisco field, colombia. Simulation optimization of wateralternatinggas process. An experimental study of alternative hot water alternating. Water alternating gas in stratified reservoirs ntnu open.
In this application a slug of water is put into an injection well, followed by gas, which exists as a separate phase from the water and oil. Pdf the water alternating gas wag process is a cyclic method of injecting alternating cycles of gas followed by water and repeating this. Paper open access experimental study of oil recovery by. Wateralternatinggas injection simulation best practices onepetro. Dec 21, 2015 a brief presentation on what water alternating gas type of enhanced oil recovery is all about slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Numerical simulation of wateralternatinggas process for. This helps to sustain higher production rates and extends the productive life of the reservoir. Simulation optimization of water alternating gas process under operational constraints.
Pdf study of various water alternating gas injection. Water alternating gas injection wag also referred to as combined water and gas injection cgw is an enhanced oil recovery eor method where water and gas injection are carried out alternately in a reservoir for a. Normal practice has been to inject natural gas into the gas cap or at the. Water flooding wateralternatinggas wag alkalisurfactantpolymer asp gas flooding miscible immiscible wateralternatinggas wag co 2 sequestration high pressure air injection gas injection water injection wag igr by late depressurization pressure maint. To enhance oil recovery, both water and gas are injected in the reservoirs in wateralternatinggas wag cycles. Fundamentals of carbon dioxideenhanced oil recovery co 2eora supporting document of the assessment. May 28, 2019 water alternating gas wag injection process is a proven enhanced oil recovery eor technology with many successful field applications around the world. Application of evolutionary algorithms erfan mohagheghiana, lesley a. Enhanced oil recovery by water alternating gas wag. Water traps gas in the reservoir when injected alternatively in wag. Novel approach for predicting water alternating gas injection. Simulation optimization of wateralternatinggas process under operational constraints. This study seeks to investigate, at laboratory conditions, the improvement in ultimate oil recovery when immiscible water alternating gas wag.
Simultaneous water alternating gas swag injection scheme on the reservoir instead of the initial injection of water and gas produced in 2 different wells. Another motivation to combine different methods is driven by some undesired results of the continuous co 2 injection such as, for instance, pipe and equipment corrosion, which demands special construction, and the organic material. Water alternating gas process has been used to improve the mobility of the flooding system and that will result in better sweep efficiency and an improvement in the oil recovery efficiency. To monitor the water and gas saturation across the uppermost reservoirs, the operator needed to log in the brinefilled injector well, which had both 7in casing and 3 12in tubing. Co2 water alternating injection can e ectively enlarge swept volume and oil displacement e ciency. In this thesis, miscible co2 wateralternatinggas co2wag injection in the tight bakken formation and the effectiveness of co2enhanced oil recovery co2eor methods in the fractured bakken formation were experimentally studied. Optimum wateralternatinggas co2wag injection in the. Chemically enhanced water alternating gas injection cewag is getting significance importance in eor after wag due to its ability to improve both the displacement and sweep efficiency.
Wateralternatinggas saturation monitoring in a single cased. Engineering, has presented a thesis titled, optimum wateralternatinggas co 2wag injection in the bakken formation, in an oral examination held on december 10, 2014. Fundamentals of carbon dioxideenhanced oil recovery eor. Water alternating gas incremental recovery factor prediction. The unique feature of the process includes use of alkaline, surfactant, and polymer as a chemical slug during the cewag process to reduce the interfacial. Two promising mobility control practices of water alternating gas wag and foam are evaluated using the inhouse compositional gas reservoir simulator doeco. Water alternating gas wag a enhanced oil recovery technique. Engineering, has presented a thesis titled, optimum water alternating gas co 2wag injection in the bakken formation, in an oral examination held on december 10, 2014. Eor methods gasbased eor co 2 injection air injection hc injection nitrogen injection flue gas injection wag water alternating gas fawag foam assisted wag waterbased eor surfactants polymer alkaline polymer gels meor microbial eor low salinity waterflood thermal methods steam sagd steam assisted gravity. Gustavo carvajal, michael konopczynski, alejandro chacon and steven knabe method, system and optimization technique to. Mechanism of injectivity loss during wateralternatinggas.
Normal practice has been to inject natural gas into the gas cap or at the top of reservoir and inject water below the oil water contact. Paper open access experimental study of oil recovery by water. Water alternating gas wag injection a novel eor technique for mature light oil fields a laboratory investigation for gs5c sand of gandhar field. The performance of wag process is measured by its incremental recovery factor over secondary recovery. Changing injection rate and duration of injection, while keeping the same wag ratio, does affect the performance of water alternating gas technique references eclipse technical description, version 2014. First, tight sandstone reservoir rock samples from the bakken formation are characterized. Continuous gas trapping causes a blocking effect that prevents the oil from being contacted by the water. The wag injection process aims to squeeze more oil out of the reservoirs. Water alternating gas wag injection is an eor method where water and gas is injected in cycles. Optimization of miscible co2 wateralternatinggas injection.
Evaluation of oil recovery by water alternating gas wag. The results of this study illustrate that water alternating gas injection and hot water alternating gas injection exert a profound impact on the amount of recovery factor. Wateralternatinggas injection is one of the most applicable eor techniques in oil reservoirs worldwide. Mcelmo creek unit waterflood, 1962, 4000 bopd fivespot pattern, 80 acre to 40 acre infills, 1976 co2 flood water alternating with gas wag, 1985, increased production from 4000 to 7000 bopd well countoil producers 90water injectors 30wag injectors 65water supply 9shutin 49 production declined. In the last few decades, much focus has been placed on enhancing oil recovery from existing fields. Laboratory data on wag and swag injections for non water wet systems are very limited especially for nearmiscible very. The liquid phase modifications include the following alternatives for water. Novel approach for predicting water alternating gas. Water alternating gas injection can potentially lead to an improved oil recovery and simultaneous cycles of alternating flooding improves the oil recovery to a greater extend. Wateralternatinggas wag injection is a relatively mature oil recovery technique in hydrocarbon reservoirs that has long attracted the interest of the oil and gas industry due to its successful.
Water flooding water alternating gas wag alkalisurfactantpolymer asp gas flooding miscible immiscible water alternating gas wag co 2 sequestration high pressure air injection gas injection water injection wag igr by late depressurization pressure maint. Co2wateralternating injection has greater popularity nowadays 11,12. Threephase relative permeability and hysteresis model for simulation of water alternating gas wag injection. This process is used mostly in co 2 floods to improve hydrocarbon contact time. Dynamic flow simulation to study flow assurance challenges. Compositional fluid flow simulation with simultaneous water alternating gas injection optimization on the upscaled synthetic reservoir cerenai. Steam stimulation steamflooding insitu combustion steamassistedgravitydrainage. Effect of surfactant on three phase relative permeability. Experimental study of oil recovery by water alternating gas wag. Moreover, the primary purpose of this study is to assess the application of alternative hot water and hot carbon dioxide gas injections in the conventional and fractured reservoir model. Optimization of hydrocarbon water alternating gas in the norne.
Wag pilot projects demonstrate that wag incremental recovery factor typically ranges from 5 to 10% of original oil in place, though up to 20% has been observed in some fields. An examination of commercial hot water heaters and steam generators of the electric water resistor type operating on alternating current shows that hydrogen and oxygen are generated within the electrode chamber. Water alternating gas incremental recovery factor prediction and. Intelligent wateralternatinggas process using downhole. An enhanced oil recovery process whereby water injection and gas injection are carried out alternately for periods of time to provide better sweep efficiency and reduce gas channeling from injector to producer. To increase the extent of the reservoir contacted by the injected gas, the gas is generally injected intermittently with. Mcelmo creek unit co2 flood program water alternating with. In the miscible co2wag injection, different wag slug sizes of 0. Moreover, the primary purpose of this study is to assess the application of alternative hot water and hot carbon dioxide gas injections in the conventional and fractured.
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