Effect of Polymer Degradation on Polymer Flooding in Heterogeneous Reservoirs
Abstract
:1. Introduction
2. Methodology
2.1. Physical Experiments
2.1.1. Materials
2.1.2. Polymer Solution Preparation and Composition
- 199 mL of brine was placed in a 500 mL beaker, whose ion component concentrations can be seen in Table 2. The solution was stirred under 200 revolutions per minute (rpm) using a JJ-1B stirrer from Xinrui Instrument Factory (Changzhou, China).
- 1.096 g of polymer was evenly added to the brine vortex for 30 s, whose properties are shown in Table 3.
- The stirrer speed was reduced to 100 rpm and kept for 2 h.
- The stirrer was stopped, and the polymer solution was deoxidized, sealed and statically stored in a brown glass bottle for 12 h.
- Steps 1–4 was repeated, 400 mL of polymer solution with a concentration of 5000 mg/L was obtained.
- 50 mL polymer solutions with a concentration of 5000 mg/L were diluted with 450, 200, 75, and 50 mL of brine, then 500, 250, 125, and 100 mL polymer solutions with concentrations of 500, 1000, 2000, and 2500 mg/L were obtained; 200 mL of polymer solution with a concentration of 5000 mg/L was diluted with 466.67 mL brine, then 666.67 mL of polymer solution with a concentration of 1500 mg/L was obtained.
- After dilution, all polymer solutions were stirred at 100 rpm for 0.5 h using the JJ-1B stirrer.
- The stirrer was stopped, and all polymer solutions were sheared under 16,900 rpm for 35 s using a Waring 7012S blender (Waring Products, Torrington, CT, USA) to simulate the degradation caused by a high shear rate in the near-wellbore region, which is called pre-shearing.
- The blender was stopped, and all polymer solutions were deoxidized, sealed, and statically stored in brown glass bottles for 12 h.
2.1.3. Viscometry
2.1.4. Polymer Degradation Experiments
- After deoxidization, the prepared polymer solution with a concentration of 1500 mg/L was sealed in a stainless-steel tank like that used in the following polymer dynamic degradation experiment, and statically placed in a thermotank at a temperature of 45 °C.
- 20 mL of the polymer solution was sampled after 1, 5, 15, 20, 40, 60, 80, 100, and 120 days, and its viscosity was measured at 45 °C. Notably, that oxygen was prevented from entering during the sampling process.
- Sands were screened by a 120-mesh screen soaked with the prepared polymer solution for 2 days to complete polymer adsorption in a thermotank at a temperature of 45 °C to avoid the effect of polymer adsorption in the experiment.
- Experimental devices were connected according to the schematic, and the temperature of the thermotank was maintained at 45 °C.
- Deoxygenation of the entire system was conducted by filling the system with nitrogen gas to avoid the effect of oxygen.
- A circulating pump was used to create the polymer solution flow through the sand layer at a flow rate of 1 m/day. Then 20 mL of the polymer solution was removed as a sample on day 1, 5, 15, 20, 40, 60, 80, 100, and 120, and its viscosity was measured at 45 °C. Avoiding oxygen in the sampling process also required careful handling.
2.1.5. Polymer Flooding Experiments
- Experimental devices were connected according to the schematic.
- The temperature of the thermotank was set to 45 °C, and the cores were saturated with water for 24 h.
- The water in the cores was displaced by the oil sample at a flow rate of 0.05 mL/min. The displacing flow rate was increased to 0.5 mL/min when the water cut at the outlet was lower than 2%, until the volume of the injected oil sample reached 10 times the PV of the cores, and no water was produced. Then, the constant flow pump was stopped, and this condition was maintained for 24 h.
- The polymer solution was used to displace at a constant flow rate of 0.64 mL/min until the volume of the injected polymer solution reached 0.64 PV. Then, the constant flow pump was stopped after the polymer flooding, and this condition was maintained for 120 days.
- Water was sequentially used to displace at a constant flow rate of 0.64 mL/min until the volume of the injected water reached 4.16 PV. After the subsequent water flooding, the constant flow pump was stopped.
2.2. Mathematical Model
2.2.1. Assumptions
- Only oil and water phases were present, and there was no mass exchange between them.
- The flow process was isothermal and the flow followed Darcy’s law.
- The fluids were compressible, and the rock was compressible and anisotropic.
- Polymer components were only divided into high and low molecular weight polymer components. The viscosity of the polymer solution was determined by the high molecular weight polymer component, and the virgin polymer solution only had the high molecular weight polymer component.
- The mixture of water and polymer was ideal, and they existed only in the water phase.
- The effects of capillary force and gravity were considered.
2.2.2. Treatment of Mechanisms
2.2.3. Mass Conservation Equations
2.2.4. Auxiliary Equations and Equations of State
2.2.5. Initial and Boundary Conditions
2.2.6. Solution Method
3. Results and Discussion
3.1. Viscosity of Polymer Solution
3.2. Polymer Degradation
3.3. Numerical Simulation
3.3.1. Validation
3.3.2. Effect of Polymer Degradation on Production Indicators
4. Conclusions
Author Contributions
Funding
Conflicts of Interest
References
- Li, H.; Lee, T.; Dziubla, T.; Pi, F.; Guo, S.; Xu, J.; Chan, L.; Haque, F.; Liang, X.; Guo, P. RNA as A Stable Polymer to Build Controllable and Defined Nanostructures for Material and Biomedical Applications. Nano Today 2015, 10, 631–655. [Google Scholar] [CrossRef] [PubMed]
- Zhong, H.; Li, Y.; Zhang, W.; Yin, H.; Lu, J.; Guo, D. Microflow Mechanism of Oil Displacement by Viscoelastic Hydrophobically Associating Water-Soluble Polymers in Enhanced Oil Recovery. Polymers 2018, 10, 628. [Google Scholar] [CrossRef]
- Assaad, J.J. Development and Use of Polymer-Modified Cement for Adhesive and Repair Applications. Constr. Build. Mater. 2018, 163, 139–148. [Google Scholar] [CrossRef]
- Kiriy, A.; Pötzsch, R.; Wei, Q.; Voit, B. High-Tech Functional Polymers Designed for Applications in Organic Electronics. Polym. Degrad. Stab. 2017, 145, 150–156. [Google Scholar] [CrossRef]
- Han, J.; Zhao, D.; Li, D.; Wang, X.; Jin, Z.; Zhao, K. Polymer-Based Nanomaterials and Applications for Vaccines and Drugs. Polymers 2018, 10, 31. [Google Scholar] [CrossRef]
- Amirian, E.; Dejam, M.; Chen, Z. Performance Forecasting for Polymer Flooding in Heavy Oil Reservoirs. Fuel 2018, 216, 83–100. [Google Scholar] [CrossRef]
- Cao, J.; Song, T.; Zhu, Y.; Wang, S.; Wang, X.; Lv, F.; Jiang, L.; Sun, M. Application of Amino-functionalized Nano-silica in Improving the Thermal Stability of Acrylamide Based Polymer for Enhanced Oil Recovery. Energy Fuels 2018, 32, 246–254. [Google Scholar] [CrossRef]
- Standnes, D.C.; Skjevrak, I. Literature Review of Implemented Polymer Field Projects. J. Pet. Sci. Eng. 2014, 122, 761–775. [Google Scholar] [CrossRef]
- Gbadamosi, A.O.; Junin, R.; Manan, M.A.; Yekeen, N.; Agi, A.; Oseh, J.O. Recent Advances and Prospects in Polymeric Nanofluids Application for Enhanced Oil Recovery. J. Ind. Eng. Chem. 2018. [Google Scholar] [CrossRef]
- Salmo, I.C.; Pettersen, Ø.; Skauge, A. Polymer Flooding at an Adverse Mobility Ratio: Acceleration of Oil Production by Crossflow into Water Channels. Energy Fuels 2017, 31, 5948–5958. [Google Scholar] [CrossRef]
- Ekkawong, P.; Han, J.; Olalotiti-Lawal, F.; Datta-Gupta, A. Multiobjective Design and Optimization of Polymer Flood Performance. J. Pet. Sci. Eng. 2017, 153, 47–58. [Google Scholar] [CrossRef]
- Algharaib, M.; Alajmi, A.; Gharbi, R. Improving Polymer Flood Performance in High Salinity Reservoirs. J. Pet. Sci. Eng. 2014, 115, 17–23. [Google Scholar] [CrossRef]
- Choi, J.; Ka, D.; Chung, T.; Jung, J.; Koo, G.; Uhm, T.; Jung, H.S.; Park, S.; Jung, H.T. Evaluation of Highly Stable Ultrahigh-Molecular-Weight Partially Hydrolyzed Polyacrylamide for Enhanced Oil Recovery. Macromol. Res. 2015, 23, 518–524. [Google Scholar] [CrossRef]
- Cai, S.; He, X.; Liu, K.; Zhang, R.; Chen, L. Interaction between HPAM and Urea in Aqueous Solution and Rheological Properties. Iran. Polym. J. 2015, 24, 663–670. [Google Scholar] [CrossRef]
- Hatzignatiou, D.G.; Moradi, H.; Stavland, A. Polymer Flow through Water- and Oil-Wet Porous Media. J. Hydrodyn. Ser. B 2015, 27, 748–762. [Google Scholar] [CrossRef]
- Ma, Y.; Hou, J. New Method for Determination of Inaccessible Pore Volume of Polymer or Crosslinking Polymer. Oilfield Chem. 2017, 34, 361–365. [Google Scholar]
- Li, A.; Song, H.; Xie, H. Influence of Inaccessible Pore Volume on Seepage Law of Polymer Flooding. Pet. Geol. Recov. Effic. 2016, 23, 70–74. [Google Scholar]
- Zhao, G.; Fang, J.; Gao, B.; Wang, Y.; Chen, A.; Wen, D.; Dai, C. Study and Application of the Adsorption of Anionic and Cationic Polymer. Oilfield Chem. 2015, 32, 62–66. [Google Scholar]
- De Oliveira, L.F.L.; Schiozer, D.J.; Delshad, M. Impacts of Polymer Properties on Field Indicators of Reservoir Development Projects. J. Pet. Sci. Eng. 2016, 147, 346–355. [Google Scholar] [CrossRef]
- Sheng, J.J.; Leonhardt, B.; Azri, N. Status of Polymer-Flooding Technology. J. Can. Pet. Technol. 2015, 54, 116–126. [Google Scholar] [CrossRef]
- Unsal, E.; Ten Berge, A.B.G.M.; Wever, D.A.Z. Low Salinity Polymer Flooding: Lower Polymer Retention and Improved Injectivity. J. Pet. Sci. Eng. 2018, 163, 671–682. [Google Scholar] [CrossRef]
- Seright, R.; Skjevrak, I. Effect of Dissolved Iron and Oxygen on Stability of Hydrolyzed Polyacrylamide Polymers. SPE J. 2015, 20, 433–441. [Google Scholar] [CrossRef]
- Ferreira, V.H.; Moreno, R.B. Polyacrylamide Mechanical Degradation and Stability in the Presence of Iron. In Proceedings of the Offshore Technology Conference Brasil, Rio de Janeiro, Brazil, 24–26, October 2017. [Google Scholar] [CrossRef]
- Sandengen, K.; Meldahl, M.M.; Gjersvold, B.; Molesworth, P.; Gaillard, N.; Braun, O.; Antignard, S. Long Term Stability of ATBS Type Polymers for Enhanced Oil Recovery. J. Pet. Sci. Eng. 2018, 169, 532–545. [Google Scholar] [CrossRef]
- Gaillard, N.; Giovannetti, B.; Leblanc, T.; Thomas, A.; Braun, O.; Favero, C. Selection of Customized Polymers to Enhance Oil Recovery from High Temperature Reservoirs. In Proceedings of the SPE Latin American and Caribbean Petroleum Engineering Conference, Quito, Ecuador, 18–20 November 2015. [Google Scholar] [CrossRef]
- Bengar, A.; Moradi, S.; Ganjeh-Ghazvini, M.; Shokrollahi, A. Optimized Polymer Flooding Projects via Combination of Experimental Design and Reservoir Simulation. Petroleum 2017, 3, 461–469. [Google Scholar] [CrossRef]
- Sharafi, M.S.; Jamialahmadi, M.; Hoseinpour, S.A. Modeling of Viscoelastic Polymer Flooding in Core-Scale for Prediction of Oil Recovery Using Numerical Approach. J. Mol. Liq. 2018, 250, 295–306. [Google Scholar] [CrossRef]
- Jackson, G.T.; Balhoff, M.T.; Huh, C.; Delshad, M. CFD-Based Representation of Non-Newtonian Polymer Injectivity for A Horizontal Well with Coupled Formation-Wellbore Hydraulics. J. Pet. Sci. Eng. 2011, 78, 86–95. [Google Scholar] [CrossRef]
- Praveen, C.; Gowda, G.V. A Finite Volume Method for A Two-Phase Multicomponent Polymer Flooding. J. Comput. Phys. 2014, 275, 667–695. [Google Scholar]
- Wang, J.; Liu, H. A Novel Model and Sensitivity Analysis for Viscoelastic Polymer Flooding in Offshore Oilfield. J. Ind. Eng. Chem. 2014, 20, 656–667. [Google Scholar] [CrossRef]
- Rego, F.B.; Botechia, V.E.; Schiozer, D.J. Heavy Oil Recovery by Polymer Flooding and Hot Water Injection Using Numerical Simulation. J. Pet. Sci. Eng. 2017, 153, 187–196. [Google Scholar] [CrossRef]
- Lu, X.A.; Jiang, H.; Smørgrav, E.; Li, J.; Ding, S.; Li, C.; Liu, G. A New Thermal Degradation Model of Polymer in High-Temperature Reservoirs. In Proceedings of the SPE/IATMI Asia Pacific Oil & Gas Conference and Exhibition, Nusa Dua, Bali, Indonesia, 20–22 October 2015. [Google Scholar] [CrossRef]
- Choi, B.; Jeong, M.S.; Lee, K.S. Temperature-Dependent Viscosity Model of HPAM Polymer through High-Temperature Reservoirs. Polym. Degrad. Stab. 2014, 110, 225–231. [Google Scholar] [CrossRef]
- Lu, X.; Jiang, H.; Li, J.; Zhao, L.; Pei, Y.; Zhao, Y.; Liu, G.; Fang, W. Polymer Thermal Degradation in High-Temperature Reservoirs. Pet. Sci. Technol. 2015, 33, 1571–1579. [Google Scholar] [CrossRef]
- Lin, C.; Zhang, X.; Liu, H. Study on Numerical Model Considering Polymer Solution Aging Process. J. Oil Gas Technol. 2012, 34, 143–147. [Google Scholar]
- Todd, M.R.; Longstaff, W.J. The Development, Testing, and Application of a Numerical Simulator for Predicting Miscible Flood Performance. J. Pet. Technol. 1972, 24, 874–882. [Google Scholar] [CrossRef]
- Adamson, A.W.; Gast, A.P. Physical Chemistry of Surfaces, 6th ed.; John Wiley & Sons: New York, NY, USA, 1997; pp. 603–615. [Google Scholar]
- Chaudhuri, A.; Vishnudas, R. A Systematic Numerical Modeling Study of Various Polymer Injection Conditions on Immiscible and Miscible Viscous Fingering and Oil Recovery in A Five-Spot Setup. Fuel 2018, 232, 431–443. [Google Scholar] [CrossRef]
- Bao, K.; Lie, K.A.; Møyner, O.; Liu, M. Fully implicit simulation of polymer flooding with MRST. Comput. Geosci. 2017, 21, 1219–1244. [Google Scholar] [CrossRef]
- Peaceman, D.W. Interpretation of Well-Block Pressures in Numerical Reservoir Simulation with Nonsquare Grid Blocks and Anisotropic Permeability. SPE J. 1983, 23, 531–543. [Google Scholar] [CrossRef]
- Deb, P.K.; Akter, F.; Imtiaz, S.A.; Hossain, M.E. Nonlinearity and Solution Techniques in Reservoir Simulation: A Review. J. Nat. Gas Sci. Eng. 2017, 46, 845–864. [Google Scholar] [CrossRef]
- Chen, Z.; Huan, G.; Ma, Y. Computational Methods for Multiphase Flows in Porous Media; SIAM: Philadelphia, PA, USA, 2006; pp. 128–198. [Google Scholar]
- Chen, Z. Reservoir Simulation: Mathematical Techniques in Oil Recovery; SIAM: Philadelphia, PA, USA, 2007; pp. 88–99. [Google Scholar]
- Fang, D.; Guo, R.; Ha, R. Acrylamide Polymer; Chemical Industry Press: Beijing, China, 2006; pp. 2–20. [Google Scholar]
- Wang, D. Study on Improving Viscosity and Oil Displacement Efficiency of HPAM Solution, Master’s Thesis, Northeast Petroleum University, Daqing, China, April 2017. [Google Scholar]
- Xian, J. Research on Rheological Properties of Polymer Solution in Porous Media, Master’s Thesis, Southwest Petroleum University, Chengdu, China, May 2017. [Google Scholar]
- Lu, G.; Shao, N.; Cao, M.; Wang, B. Effect of Polymer Chain Structure on Rheological Behavior of Polyamide Imide Solution. Eng. Plastic. Appl. 2016, 44, 90–92. [Google Scholar]
- Wei, B. Flow Characteristics of Three Enhanced Oil Recovery Polymers in Porous Media. J. Appl. Polym. Sci. 2015, 132, 41598. [Google Scholar] [CrossRef]
- Mansour, A.M.; Al-Maamari, R.S.; Al-Hashmi, A.S.; Zaitoun, A.; Al-Sharji, H. In-Situ Rheology and Mechanical Degradation of EOR Polyacrylamide Solutions under Moderate Shear Rates. J. Pet. Sci. Eng. 2014, 115, 57–65. [Google Scholar] [CrossRef]
- Jouenne, S.; Chakibi, H.; Levitt, D. Polymer Stability After Successive Mechanical-Degradation Events. SPE J. 2018. [Google Scholar] [CrossRef]
- Zhu, H.; Chen, S.; Wang, C.; Song, A.; Wang, J.; Huang, B. Effects of Mechanical Shear on Associative Polymer Solution Microstructure, Oil Drill. Prod. Technol. 2012, 34, 82–85. [Google Scholar]
- Xin, X.; Li, Y.; Yu, G.; Wang, W.; Zhang, Z.; Zhang, M.; Ke, W.; Kong, D.; Wu, K.; Chen, Z. Non-Newtonian Flow Characteristics of Heavy Oil in the Bohai Bay Oilfield: Experimental and Simulation Studies. Energies 2017, 10, 1698. [Google Scholar] [CrossRef]
- Lamas, L.F.; Botechia, V.E.; Correia, M.G.; Schiozer, D.J.; Delshad, M. Influence of Polymer Properties on Selection of Production Strategy for A Heavy Oil Field. J. Pet. Sci. Eng. 2017, 163, 110–118. [Google Scholar] [CrossRef]
- Rezaei, A.; Abdi-Khangah, M.; Mohebbi, A.; Tatar, A.; Mohammadi, A.H. Using Surface Modified Clay Nanoparticles to Improve Rheological Behavior of Hydrolized Polyacrylamid (HPAM) Solution for Enhanced Oil Recovery with Polymer Flooding. J. Mol. Liq. 2016, 222, 1148–1156. [Google Scholar] [CrossRef]
- Giraldo, L.J.; Giraldo, M.A.; Llanos, S.; Maya, G.; Zabala, R.D.; Nassar, N.N.; Franco, C.A.; Alvarado, V.; Cortés, F.B. The Effects of Sio2 Nanoparticles on The Thermal Stability and Rheological Behavior of Hydrolyzed Polyacrylamide Based Polymeric Solutions. J. Pet. Sci. Eng. 2017, 159, 841–852. [Google Scholar] [CrossRef]
- Liu, R.; Pu, W.; Du, D.; Gu, J.; Sun, L. Manipulation of Star-Like Polymer Flooding Systems Based on Their Comprehensive Solution Properties and Flow Behavior in Porous Media. J. Pet. Sci. Eng. 2018, 164, 467–484. [Google Scholar] [CrossRef]
- Sveistrup, M.; van Mastrigt, F.; Norrman, J.; Picchioni, F.; Paso, K. Viability of Biopolymers for Enhanced Oil Recovery. J. Dispersion Sci. Technol. 2016, 37, 1160–1169. [Google Scholar] [CrossRef]
- Molnes, S.N.; Torrijos, I.P.; Strand, S.; Paso, K.G.; Syverud, K. Sandstone Injectivity and Salt Stability of Cellulose Nanocrystals (CNC) Dispersions-Premises for Use of CNC in Enhanced Oil Recovery. Ind. Crop. Prod. 2016, 93, 152–160. [Google Scholar] [CrossRef]
- Molnes, S.N.; Paso, K.G.; Strand, S.; Syverud, K. The Effects of pH, Time and Temperature on the Stability and Viscosity of Cellulose Nanocrystal (CNC) Dispersions: Implications for Use in Enhanced Oil Recovery. Cellulose 2017, 24, 4479–4491. [Google Scholar] [CrossRef]
- Molnes, S.N.; Mamonov, A.; Paso, K.G.; Strand, S.; Syverud, K. Investigation of a New Application for Cellulose Nanocrystals: A Study of the Enhanced Oil Recovery Potential by Use of a Green Additive. Cellulose 2018, 25, 2289–2301. [Google Scholar] [CrossRef]
Parameter | Value | |
---|---|---|
Single carbon number, wt% | C3 | 0.03 |
C4 | 0.08 | |
C5 | 0.16 | |
C6 | 0.75 | |
C7 | 1.76 | |
C8 | 2.16 | |
C9 | 3.59 | |
C10 | 4.46 | |
C11 | 5.13 | |
C12 | 5.76 | |
C12+ | 76.12 | |
Density (45 °C), Kg/m3 | 880 | |
Viscosity (45 °C), mPa∙s | 8.9 |
Ion Components | Concentration, mg/L |
---|---|
Na+ and K+ | 85.8 |
Ca2+ | 24.1 |
Mg2+ | 10.9 |
HCO3− | 122 |
CO32− | 30 |
SO42− | 62.4 |
Cl− | 53.2 |
TDS | 388.4 |
Properties | Description/Value |
---|---|
Type | HPAM |
Molecular weight | 2.5 × 107 |
Solid content, wt% | 91.2 |
Hydrolysis degree, % | 26 |
Filtration factor | 1.2 |
Dissolution rate, hour | <2 |
Insoluble matter, wt% | 0.1 |
Granularity ≥1.0 mm, % | 4.8 |
Granularity ≤0.2 mm, % | 2.6 |
Parameters | Core Name | ||
---|---|---|---|
High Permeability Layer (HPL) | Middle Permeability Layer (MPL) | Low Permeability Layer (LPL) | |
Length, cm | 29.89 | 29.9 | 29.89 |
Width, cm | 4.43 | 4.45 | 4.44 |
Height, cm | 2.5 | 2.5 | 2.5 |
Porosity, % | 31.5 | 26.8 | 26.1 |
Permeability, mD | 1250 | 600 | 120 |
Input Parameters | Value | Input Parameters | Value |
---|---|---|---|
Initial porosity in HPL, MPL and LPL, fraction | 0.258, 0.254, 0.249 | Water formation volume factor | 1.016 |
Initial permeability in x direction in HPL, MPL and LPL, mD | 1250, 600, 120 | Polymer concentration, mg/L | 1500 |
Initial permeability in y direction in HPL, MPL and LPL, mD | 1250, 600, 120 | Inaccessible pore volume factor in HPL, MPL and LPL, fraction | 0.05, 0.06, 0.08 |
Initial permeability in z direction in HPL, MPL and LPL, mD | 125, 60, 12 | Maximum polymer absorption in HPL, MPL and LPL, Kg/Kg rock | 1.0 × 10−5, 1.1 × 10−5, 1.4 × 10−5 |
Reservoir temperature, °C | 45 | Residual resistance factor in HPL, MPL and LPL | 1.35, 1.40, 2.20 |
Rock density in HPL, MPL and LPL, Kg/m3 | 2580, 2600, 2620 | Initial reservoir pressure, MPa | 10 |
Rock compressibility in HPL, MPL and LPL, MPa−1 | 2.8 × 10−3, 2.76 × 10−3, 2.7 × 10−3 | Initial water saturation in HPL, MPL and LPL, fraction | 0.261, 0.268, 0.315 |
Stock tank oil density, Kg/m3 | 880 | Initial oil saturation in HPL, MPL and LPL, fraction | 0.739, 0.732, 0.685 |
Initial oil viscosity, mPa∙s | 8.9 | Bottom hole pressure of production well, MPa | 10 |
Oil compressibility, MPa−1 | 1.2 × 10−3 | Injection rate, m3/day | 0.64 |
Oil formation volume factor | 1.068 | Injected water during water flooding, PV | 1.03 |
Initial water density, Kg/m3 | 1000 | Injected polymer solution during polymer flooding, PV | 0.64 |
Water viscosity, mPa∙s | 0.69 | Injected water during subsequent water flooding after polymer flooding, PV | 1.06 |
Water compressibility, MPa−1 | 4.26 × 10−4 |
Parameters of the Experimental Simulation | Value |
---|---|
Length of the block along x, cm | 0.96 |
Length of the block along y, cm | 0.89 |
Length of the block along z in each layer, cm | 2.5, 0.2, 2.5, 0.2, 2.5 |
Injection rate, cm3/min | 0.64 |
Injected polymer solution during polymer flooding, PV | 0.64 |
First-order static degradation rate constant, day−1 | 0.0017 |
First-order dynamic degradation rate constant, day−1 | 0.0022 |
Interval between polymer flooding and subsequent water flooding, day | 120 |
Injected water during subsequent water flooding after polymer flooding, PV | 4.16 |
Production Indicators | First-Order Dynamic Degradation Rate Constant, Day−1 | |||
---|---|---|---|---|
0.001 | 0.01 | 0.02 | 0.1 | |
Pressure difference, MPa | 0.28 | 1.24 | 1.48 | 1.74 |
Oil production, m3/d | 0.00 | 0.00 | 0.01 | 0.03 |
Water production, m3/d | 0.00 | 0.00 | −0.01 | −0.04 |
Water cut, % | −0.45 | 0.07 | −1.26 | −5.53 |
Cumulative oil production, m3 | 0.67 | 5.72 | 10.65 | 14.10 |
Cumulative water production, m3 | −0.84 | −6.66 | −12.10 | −15.90 |
HPL flow diversion ratio, % | 0.80 | 2.35 | 1.96 | −0.36 |
MPL flow diversion ratio, % | −0.90 | −3.45 | −3.61 | −1.62 |
LPL flow diversion ratio, % | 0.10 | 1.10 | 1.66 | 1.98 |
Oil recovery, % | 0.37 | 3.15 | 5.87 | 7.77 |
© 2018 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
Share and Cite
Xin, X.; Yu, G.; Chen, Z.; Wu, K.; Dong, X.; Zhu, Z. Effect of Polymer Degradation on Polymer Flooding in Heterogeneous Reservoirs. Polymers 2018, 10, 857. https://doi.org/10.3390/polym10080857
Xin X, Yu G, Chen Z, Wu K, Dong X, Zhu Z. Effect of Polymer Degradation on Polymer Flooding in Heterogeneous Reservoirs. Polymers. 2018; 10(8):857. https://doi.org/10.3390/polym10080857
Chicago/Turabian StyleXin, Xiankang, Gaoming Yu, Zhangxin Chen, Keliu Wu, Xiaohu Dong, and Zhouyuan Zhu. 2018. "Effect of Polymer Degradation on Polymer Flooding in Heterogeneous Reservoirs" Polymers 10, no. 8: 857. https://doi.org/10.3390/polym10080857