scholarly journals Adaptive study on polymer flooding of secondary reservoir and infilling uniform

2018 ◽  
Vol 175 ◽  
pp. 01006
Author(s):  
Xu WenBo
Keyword(s):  
Oil Recovery ◽  
Physical Simulation ◽  
Injection Pressure ◽  
Leading Edge ◽  
Polymer Flooding ◽  
Water Flooding ◽  
Monitoring Methods ◽  
Sweep Efficiency ◽  
Plane Sweep ◽  
Polymer Injection

For the main polymer flooding oilfield expansion and infill wells three times the area of deployment, the proposed development mode II oil reservoir of polymer flooding and thin and poor combination of three encryption. In this paper, the use of leading edge water monitoring methods and principles of the plane heterogeneity through physical simulation to study the effects of different mining methods II oil and a combination of the three encryption effects of flooding. Studies have shown that, together with the water flooding recovery can be increased by nearly 19 percent, higher than the water poly alternate drive about 4%, the injection pressure is about three types of reservoir 0.3MPa, flat stage water flood sweep efficiency compared with an average of 30.95%. Meanwhile polymer injection can increase oil recovery by 21%, but the limited ability of three types of oil injection, polymer injection pressure during injection 0.22PV up to 0.8MPa, water flooding stage by an average of 30 percent compared to the plane sweep efficiency. The water flooding recovery poly alternately raise only 15%, an average increase of 26.95 percent driven phase plane sweep efficiency than water. Theoretical results of this study may provide a reliable basis for the future development of efficient thin and poor reservoirs.

An Easy Calculation Method on Sweep Efficiency of Chemical Flooding

2013 ◽  
Vol 275-277 ◽  
pp. 496-501
Author(s):  
Fu Qing Yuan ◽  
Zhen Quan Li
Keyword(s):  
Oil Recovery ◽  
Orthogonal Design ◽  
Polymer Flooding ◽  
Water Flooding ◽  
Solution Viscosity ◽  
Chemical Flooding ◽  
Oil Viscosity ◽  
Sweep Efficiency ◽  
Easy Calculation ◽  
Polymer Compound

According to the geological parameters of Shengli Oilfield, sweep efficiency of chemical flooding was analyzed according to injection volume, injection-production parameters of polymer flooding or surfactant-polymer compound flooding. The orthogonal design method was employed to select the important factors influencing on expanding sweep efficiency by chemical flooding. Numerical simulation method was utilized to analyze oil recovery and sweep efficiency of different flooding methods, such as water flooding, polymer flooding and surfactant-polymer compound flooding. Finally, two easy calculation models were established to calculate the expanding degree of sweep efficiency by polymer flooding or SP compound flooding than water flooding. The models were presented as the relationships between geological parameters, such as effective thickness, oil viscosity, porosity and permeability, and fluid parameters, such as polymer-solution viscosity and oil-water interfacial tension. The precision of the two models was high enough to predict sweep efficiency of polymer flooding or SP compound flooding.

scholarly journals Laboratory Study on EOR in Offshore Oilfields by Variable Concentrations Polymer Flooding

2017 ◽  
Vol 10 (1) ◽  
pp. 94-107 ◽  
Author(s):  
Kaoping Song ◽  
Ning Sun ◽  
Yanfu Pi
Keyword(s):  
Oil Recovery ◽  
Field Application ◽  
Polymer Flooding ◽  
Water Flooding ◽  
Displacement Efficiency ◽  
Constant Concentration ◽  
Sweep Efficiency ◽  
Displacement Effect ◽  
Fracture Pressure ◽  
Recovery Technique

Background: Polymer flooding is the most commonly applied chemical enhanced-oil-recovery technique in offshore oilfields. However, there are challenges and risks in applying the technology of polymer flooding to offshore heavy oil development. Objective: This paper compared the spread law and the displacement effect of different injection modes and validated the feasibility of enhancing oil recovery by variable concentrations polymer flooding. Method: Two types of laboratory experiments were designed by using micro etching glass models and heterogeneous artificial cores. Furthermore, in order to determine a better polymer flooding mode, the displacement results, displacement characteristic curves and oil saturation distribution of heterogeneous artificial cores were also compared, respectively. Results: The experimental results showed that the recovery of variable concentrations polymer flooding was higher than that of constant concentration polymer flooding, under conditions of same total amount of polymer and similar water flooding recovery. Its sweep efficiency and displacement efficiency were also significantly higher than those of constant concentration polymer flooding. Moreover, variable concentrations polymer flooding had lower peak pressure and was at lower risk for reaching the formation fracture pressure. Conclusion: As a consequence, variable concentrations polymer flooding has certain feasibility for heterogeneous reservoir in offshore oilfields, and can improve interlayer heterogeneity to further tapping remaining oil in medium and low permeability layer. Conclusions of this paper can provide reference for the field application of polymer flooding in offshore oilfields.

Laboratory Investigations of Factors Influencing Polymer Flood Performance

1975 ◽  
Vol 15 (04) ◽  
pp. 338-346 ◽  
Author(s):  
M.T. Szabo
Keyword(s):  
Oil Recovery ◽  
Polymer Solutions ◽  
Polymer Concentration ◽  
Polymer Flooding ◽  
Mobility Control ◽  
Sweep Efficiency ◽  
Experimental Conditions ◽  
Polymer Injection ◽  
Polymer Flood

Abstract Numerous polymer floods were performed in unconsolidated sand packs using a C14-tagged, cross-linked, partially hydrolyzed ployacrylamide, and the data are compared with brine-flood performance in the same sands. performance in the same sands. The amount of "polymer oil" was linearly proportional to polymer concentration up to a proportional to polymer concentration up to a limiting value. The upper limit of polymer concentration yielding additional polymer oil was considerably higher for a high-permeability sand than for a low-permeability sand. It is shown that a minimum polymer concentration exists, below which no appreciable polymer oil can be produced in high-permeability sands. The effect of polymer slug size on oil recovery is shown for various polymer concentrations, and the results from these tests are used to determine the optimum slug size and polymer concentration for different sands. The effect of salinity was studied by using brine and tap water during polymer floods under similar conditions. Decreased salinity resulted in improved oil recovery at low, polymer concentrations, but it had little effect at higher polymer concentrations. Polymer injection that was started at an advanced stage of brine flood also improved the oil recovery in single-layered sand packs. Experimental data are presented showing the effect of polymer concentration and salinity on polymer-flood performance in stratified reservoir polymer-flood performance in stratified reservoir models. Polymer concentrations in the produced water were measured by analyzing the radioactivity of effluent samples, and the amounts of retained polymer in the stratified models are given for each polymer in the stratified models are given for each experiment. Introduction In the early 1960's, a new technique using dilute polymer solutions to increase oil recovery was polymer solutions to increase oil recovery was introduced in secondary oil-recovery operations. Since then, this new technique has attained wide-spread commercial application. The success and the complexity of this new technology has induced many authors to investigate many aspects of this flooding technique. Laboratory and field studies, along with numerical simulation of polymer flooding, clearly demonstrated that polymer additives increase oil recovery. polymer additives increase oil recovery. Some of the laboratory results have shown that applying polymers in waterflooding reduces the residual oil saturation through an improvement in microscopic sweep efficiency. Other laboratory studies have shown that applying polymer solutions improves the sweep efficiency in polymer solutions improves the sweep efficiency in heterogeneous systems. Numerical simulation of polymer flooding, and a summary of 56 field applications, clearly showed that polymer injection initiated at an early stage of waterflooding is more efficient than when initiated at an advanced stage. Although much useful information has been presented, the experimental conditions were so presented, the experimental conditions were so variable that difficulties arose in correlating the numerical data. So, despite this good data, a systematic laboratory study of the factors influencing the performance of polymer flooding was still lacking in the literature. The purpose of this study was to investigate the effect of polymer concentration, polymer slug size, salinity in the polymer bank, initial water saturation, and permeability on the performance of polymer floods. The role of oil viscosity did not constitute a subject of this investigation. However, some of the data indicated that the applied polymer resulted in added recovery when displacing more viscous oil. The linear polymer-flood tests were coupled with tests in stratified systems, consisting of the same sand materials used in linear flood tests. Thus, it was possible to differentiate between the role of polymer in mobility control behind the flood front in each layer and its role in mobility control in the entire stratified system through improvement in vertical sweep efficiency. A radioactive, C14-tagged hydrolyzed polyacrylamide was used in all oil-recovery tests. polyacrylamide was used in all oil-recovery tests. SPEJ P. 338

scholarly journals Chemical Migration and Emulsification of Surfactant-Polymer Flooding

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Jierui Li ◽  
Weidong Liu ◽  
Guangzhi Liao ◽  
Linghui Sun ◽  
Sunan Cong ◽  
...  
Keyword(s):  
Oil Recovery ◽  
Polymer Flooding ◽  
Water Flooding ◽  
Sweep Efficiency ◽  
Equal Concentration ◽  
Multiple Sample ◽  
Water Cut ◽  
And Migration ◽  
Swept Volume ◽  
Chemical Migration

With a long sand-packed core with multiple sample points, a laboratory surfactant-polymer flooding experiment was performed to study the emulsification mechanism, chemical migration mechanism, and the chromatographic separation of surfactant-polymer flooding system. After water flooding, the surfactant-polymer flooding with an emulsified system enhances oil recovery by 17.88%. The water cut of produced fluid began to decrease at the injection of 0.4 pore volume (PV) surfactant-polymer slug and got the minimum at 1.2 PV. During the surfactant-polymer flooding process, the loss of polymer is smaller than that of surfactant, the dimensionless breakthrough time of polymer is 1.092 while that of surfactant is 1.308, and the dimensionless equal concentration distance of the chemical is 0.65. During surfactant-polymer flooding, the concentration of surfactant controls the formation of the emulsion. From 50 cm to 600 cm, as the migration distance increases, the concentration of surfactant decreases, and the emulsification strength and duration decrease gradually. With the formation of emulsion, the viscosity of the emulsion is relatively stable, which is beneficial to enhanced oil recovery. With the shear of reservoirs and migration of surfactant-polymer slug, the emulsion is formed to improve the swept volume and sweep efficiency and enhance oil recovery.

scholarly journals Investigation of an Improved Polymer Flooding Scheme by Compositionally-Tuned Slugs

Processes ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 197 ◽  
Author(s):  
Ryan Santoso ◽  
Victor Torrealba ◽  
Hussein Hoteit
Keyword(s):  
Oil Recovery ◽  
Polymer Flooding ◽  
Solution Viscosity ◽  
Design Parameters ◽  
High Concentration ◽  
Sweep Efficiency ◽  
Polymer Injection ◽  
Low Salinity ◽  
Injection Scheme ◽  
Vertical Heterogeneity

Polymer flooding is an effective enhanced oil recovery technology used to reduce the mobility ratio and improve sweep efficiency. A new polymer injection scheme is investigated that relies on the cyclical injection of low-salinity, low-concentration polymer slugs chased by high-salinity, high-concentration polymer slugs. The effectiveness of the process is a function of several reservoir and design parameters related to polymer type, concentration, salinity, and reservoir heterogeneity. We use reservoir simulations and design-of-experiments (DoE) to investigate the effectiveness of the proposed polymer injection scheme. We show how key objective functions, such as recovery factor and injectivity, are impacted by the reservoir and design parameters. In this study, simulations showed that the new slug-based process was always superior to the reference polymer injection scheme using the traditional continuous injection scheme. Our results show that the process is most effective when the polymer weight is high, corresponding to large inaccessible pore-volumes, which enhances polymer acceleration. High vertical heterogeneity typically reduces the process performance because of increased mixing in the reservoir. The significance of this process is that it allows for increased polymer solution viscosity in the reservoir without increasing the total mass of polymer, and without impairing polymer injectivity at the well.

scholarly journals Evaluation of Polymer Alternating Waterflooding in Multilayered Heterogeneous Waterflooded Reservoir

2018 ◽  
Vol 171 ◽  
pp. 04001
Author(s):  
Warut Tuncharoen ◽  
Falan Srisuriyachai
Keyword(s):  
Numerical Simulation ◽  
Viscous Fluid ◽  
Polymer Solution ◽  
Oil Recovery ◽  
High Viscosity ◽  
Polymer Flooding ◽  
Operating Parameters ◽  
Sweep Efficiency ◽  
Polymer Injection ◽  
Water Breakthrough

Polymer flooding is widely implemented to improve oil recovery since polymer can increase sweep efficiency and smoothen heterogeneous reservoir profile. However, polymer solution is somewhat difficult to be injected due to high viscosity and thus, water slug is recommended to be injected before and during polymer injection in order to increase an ease of injecting this viscous fluid into the wellbore. In this study, numerical simulation is performed to determine the most appropriate operating parameters to maximize oil recovery. The results show that pre-flushed water should be injected until water breakthrough while alternating water slug size should be as low as 5% of polymer slug size. Concentration for each polymer slugs should be kept constant and recommended number of alternative cycles is 2. Combining these operating parameters altogether contributes to oil recovery of 53.69% whereas single-slug polymer flooding provides only 53.04% which is equivalent to 8,000 STB of oil gain.

scholarly journals A Pore-Scale Investigation of Residual Oil Distributions and Enhanced Oil Recovery Methods

Energies ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3732 ◽  
Author(s):  
Yaohao Guo ◽  
Lei Zhang ◽  
Guangpu Zhu ◽  
Jun Yao ◽  
Hai Sun ◽  
...  
Keyword(s):  
Porous Media ◽  
Enhanced Oil Recovery ◽  
Oil Recovery ◽  
Polymer Flooding ◽  
Water Flooding ◽  
Scale Model ◽  
Pore Scale ◽  
Residual Oil ◽  
Sweep Efficiency ◽  
Significant Difference

Water flooding is an economic method commonly used in secondary recovery, but a large quantity of crude oil is still trapped in reservoirs after water flooding. A deep understanding of the distribution of residual oil is essential for the subsequent development of water flooding. In this study, a pore-scale model is developed to study the formation process and distribution characteristics of residual oil. The Navier–Stokes equation coupled with a phase field method is employed to describe the flooding process and track the interface of fluids. The results show a significant difference in residual oil distribution at different wetting conditions. The difference is also reflected in the oil recovery and water cut curves. Much more oil is displaced in water-wet porous media than oil-wet porous media after water breakthrough. Furthermore, enhanced oil recovery (EOR) mechanisms of both surfactant and polymer flooding are studied, and the effect of operation times for different EOR methods are analyzed. The surfactant flooding not only improves oil displacement efficiency, but also increases microscale sweep efficiency by reducing the entry pressure of micropores. Polymer weakens the effect of capillary force by increasing the viscous force, which leads to an improvement in sweep efficiency. The injection time of the surfactant has an important impact on the field development due to the formation of predominant pathway, but the EOR effect of polymer flooding does not have a similar correlation with the operation times. Results from this study can provide theoretical guidance for the appropriate design of EOR methods such as the application of surfactant and polymer flooding.

scholarly journals Evaluation of Polymer Flooding in a Highly Stratified Heterogeneous Reservoir. A Field Case Study

2020 ◽  
Vol 16 ◽  
Keyword(s):  
Oil Recovery ◽  
History Matching ◽  
Lower Layer ◽  
Polymer Flooding ◽  
Economic Life ◽  
Water Flooding ◽  
Base Case ◽  
Sweep Efficiency ◽  
Sector Model ◽  
Reservoir Simulator

Oil and gas companies are looking for proven hydrocarbon reserves from their mature drained reservoirs to extend the production and economic life of these fields. The chemical enhanced oil recovery (CEOR) is an attractive water-based EOR method for these mature fields. The polymer flooding (PF) is a widely applied process in reservoirs with low sweep efficiency after the water flooding (WF). The target Colombian field has one of the first polymer pilots in the region with positive results of oil recovery in “A” sands. Thus, the operator is interested in the expansion of PF for the same reservoir and even in deeper reservoir sands. This paper focuses in the evaluation of different scenarios of PF for the producer in layers A and B with a mechanistic simulation model, thus obtaining new recommendations for the recovery strategy in the field. A sector model was constructed from a full field model using a commercial reservoir simulator to the in-house chemical flooding reservoir simulator: UTCHEMRS. This sector model was also migrated to a second commercial simulator allowing a performance comparison for these three simulators. UTCHEMRS model results were compared with the commercial simulators through the history matching (HM) phase. The primary and waterflood history match was in agreement with the field data. Simulation results suggested that PF for the base case in “A” sands presented an incremental oil recovery of up to 12% additional to water flooding. Additionally, PF was extended to the lower layer “B” sand to investigate the potential of polymer injection. The PF injection in both reservoirs simultaneously loses sweep efficiency and decreases the oil recovery to about 3%. However, a hypothetical case of new infill producer wells with the objective of testing the individual reservoir performance has revealed that PF is having significant upside from B sands as well.

scholarly journals Experimental Study on Medium Viscosity Oil Displacement Using Viscoelastic Polymer

Geofluids ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Huiying Zhong ◽  
Qiuyuan Zang ◽  
Hongjun Yin ◽  
Huifen Xia
Keyword(s):  
Oil Recovery ◽  
Polymer Flooding ◽  
Water Soluble ◽  
Water Flooding ◽  
Bohai Bay ◽  
Residual Oil ◽  
Displacement Efficiency ◽  
Sweep Efficiency ◽  
Oil Displacement ◽  
Medium Viscosity

With the growing demand for oil energy and a decrease in the recoverable reserves of conventional oil, the development of viscous oil, bitumen, and shale oil is playing an important role in the oil industry. Bohai Bay in China is an offshore oilfield that was developed through polymer flooding process. This study investigated the pore-scale displacement of medium viscosity oil by hydrophobically associating water-soluble polymers and purely viscous glycerin solutions. The role and contribution of elasticity on medium oil recovery were revealed and determined. Comparing the residual oil distribution after polymer flooding with that after glycerin flooding at a dead end, the results showed that the residual oil interface exhibited an asymmetrical “U” shape owing to the elasticity behavior of the polymer. This phenomenon revealed the key of elasticity enhancing oil recovery. Comparing the results of polymer flooding with that of glycerin flooding at different water flooding sweep efficiency levels, it was shown that the ratio of elastic contribution on the oil displacement efficiency increased as the water flooding sweep efficiency decreased. Additionally, the experiments on polymers, glycerin solutions, and brines displacement medium viscosity oil based on a constant pressure gradient at the core scale were carried out. The results indicated that the elasticity of the polymer can further reduce the saturation of medium viscosity oil with the same number of capillaries. In this study, the elasticity effect on the medium viscosity oil interface and the elasticity contribution on the medium viscosity oil were specified and clarified. The results of this study are promising with regard to the design and optimum polymers applied in an oilfield and to an improvement in the recovery of medium viscosity oil.

scholarly journals NEW AQUEOUS POLYMER FOR HIGH-TEMPERATURE RESERVOIRS

2018 ◽  
Vol 15 (30) ◽  
pp. 380-386
Author(s):  
Y. V. SAVINYKH ◽  
L. D. LANG
Keyword(s):  
High Temperature ◽  
Oil Recovery ◽  
High Salinity ◽  
Sea Water ◽  
Polymer Flooding ◽  
Water Soluble ◽  
Water Flooding ◽  
Polymer Gel ◽  
Sweep Efficiency ◽  
Water Soluble Polymer

Polymer flooding is technologically simple and highly effective method of enhanced oil recovery. The method is based on adding a small amount of polymer in conventional water flooding of oil reservoirs. The increase in viscosity and the reduction of the mobility of injected water are to equalize the displacement front by slowing the moving of water in the highly permeable zones and restricting the formation of water finger. These factors help to increase the sweep efficiency and oil-water displacement efficiency during flooding. Polymer flooding has been used successfully in clastic and carbonate reservoirs, as well as in low-permeability reservoirs such as a fractured basement. However, most of the current polymer gel used for control water flows are decayed by a high content of ions Ca2+ and Mg2+ in formation water or in injected water. Similarly, polymer gels lose their stability at high reservoir temperature (above 70°C). Developing water-soluble polymer, which does not change their rheological properties under high salinity and high temperature (over 100°C), is very important when producing offshore, where sea water is commonly used for flooding (high salinity of 30-40 g/L).

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