The primary result obtained from the basic flood performance evaluation using CMG software revealed that the use of linseed gum led to a significant improvement in oil recovery, raising the recovery rate from 53% to 74.3% and reaching saturation remaining oil of 18.5%. Furthermore, the potential for additional oil recovery remains in the field-scale environment as residual oil saturation has not yet been reached.
INTRODUCTION
- Study Background
- Problem Statement
- Research Objectives
- Scope of the study
- Significance of the study
- Organization of the Rest of the Chapters
- Summary
Conducting an optimization study using the CMOST simulation tool to determine the optimal conditions for the implementation of linseed gum in practical EOR applications. Furthermore, the study aims to scale up the simulation to field scale and conduct an optimization study using the CMOST simulation tool to determine the optimal conditions for the implementation of linseed gum in practical EOR applications.
LITERATURE REVIEW
Analysis of EOR Techniques: Mechanisms, Methodologies, and Applications
- The concept of EOR
- Active mechanisms in EOR applications
- EOR methods
Assessment of the effectiveness of fluid injection in pore rock oil displacement focuses on oil displacement at the microscopic level. Where 𝑣 = interstitial velocity, 𝜇𝐷 = viscosity of the displacing fluid, 𝜎𝑜𝐷 = interfacial tension between displaced and displacing fluid, 𝜃 = contact angle.
Chemical-Enhanced Oil Recovery
- The Concept of Chemical-Enhanced Oil Recovery
Classification of EOR techniques (extra heavy oil/bitumen is defined as having viscosity greater than 1000 cp and an API range of 6 to 20) (Babadagli, 2019). Chemical Enhanced Oil Recovery (EOR) methods use a chemical mixture as a displacement agent, which causes a reduction in the number of capillaries or an increase in the mobility ratio.
Polymer Flooding for Enhanced Oil Recovery: Mechanisms, Formulations, and
- Historical Evolution of Polymer Applications in Oil Recovery
- Polymer Flooding in Enhanced Oil Recovery: Definition and Mechanisms
- Characteristics of PAM as the main type of synthetic polymer
The purpose of polymer flooding is to increase the mobility ratio between oil and water by increasing the viscosity of the injected water (Sandiford, 1964). In special cases, IPV can make up 30% of the entire pore volume (Pancharoen et al., 2010).
Natural polymers
- Types of Biopolymers and their characteristics
- Simulation studies of biopolymer floodings
A soluble dietary fiber called flaxseed gum is found in the flaxseed hull (Liu et al., 2018). In a study conducted by Xing et al. 2015), the rheological properties of flaxseed gum were investigated to investigate the influence of extraction temperature.
Field applications of polymer flooding
The start with polymer injection at the Pelican Lake field in Canada was continuous, with a pilot followed by rapid expansion. The Pelican Lake field polymer flood is the largest polymer flood for horizontal well applications and is also the largest heavy oil polymer flood. In locations intended for the use of polymers, the viscosity of the oil is in the range of cp.
According to a study by Okechukwu et al. 2021), the use of polymer in the Daqing oil field resulted in an additional 12% recovery of OOIP.
Summary
METHODOLOGY
- Introduction
- Fundamentals of numerical simulation
- General Description of CMG Simulator
- Phase 1: Construction of dynamic model for waterflooding
- Phase 2: History Matching of Waterflooding and Polymer Flooding Models Using the
- Phase 3: Upscaling to 3D field scale
- Phase 4: Optimization with CMG CMOST
Before attempting to simulate and match the history of the polymer flood data, a water flood was modeled. The curves represent the relative permeability of oil and water, demonstrating the ease of flow of the phases. One of the most important features of CMG CMOST for creating proxy models is the "History Matching and Optimization" module.
After a successful historical match of the water flood and polymer flood performance, the next step is to "upgrade" the model to 3-D.
RESULTS AND DISCUSSION
Introduction
Modeling a Waterflooding
The cumulative oil production result of the base case, namely water flooding, is shown in Figure 12. In the laboratory experiments, the cumulative oil production increased significantly up to 75 minutes of production, after which it experienced a sharp increase until the end of the period. water flooding process. The outcome of the matching procedure for the cumulative oil production history is shown in Figure 13 and Table 7.
The input parameters of the base case will remain unchanged due to the satisfactory performance of the numerical model results during the history matching process.
Effect of Water Flooding on Water Cut
The high water cut during the core waterflooding process can be attributed to several factors related to the properties of the reservoir and the fluids involved in the process. One of the factors that can affect the water cut is the permeability of the rock formation. If the rock has high permeability, water can easily flow through the formation and displace oil resulting in a high water cut.
Injection rate and water pressure can also affect water cutoff during core waterflooding.
Effect of Water Flooding on Recovery Factor
The main reason for the high water drawdown observed in our simulation is the significant difference in viscosity between the injected water (1.24 cp) and the oil in the porous medium (19.35 cp). This causes the injected water to flow through a single channel, bypassing the major oil fractions in the pores, commonly called viscous toe displacement. The viscous toe effect is more pronounced in viscous oil reservoirs, where the high viscosity of the oil restricts its flow through the reservoir and causes the formation of channels of high permeability through which water can easily flow.
It should be noted that the water cut was not estimated during the laboratory experiment, and that there is no data to verify the results obtained from the simulation model.
Effect of Water Flooding on Remaining Oil Saturation
Modeling a natural polymer flooding
History matching of polymer flooding model
The table below gives the tuning parameter values for the base case and for the optimized case. Based on Table 8, it is clear that the default input values for the current polymer and the defined polymer concentrations in the base case were both zero. The last tuned parameter, permeability reduction, had a value of 1.6685 in the optimized case, indicating the effect of the permeability reduction during the core flooding.
After substituting the optimized values obtained from historical matching for the input parameters of the base case in the new model, the cumulative oil production results obtained from numerical simulations and experimental data were found to be in close agreement, as shown in Figure 18. .
Effect of polymer flooding on water cut
Effect of polymer flooding on recovery factor
For the comparison, Olabode et al. 2020) performed core flooding experiments on sandstone rocks using starch biopolymer derived from waste material. of oil from the core after injection of the biopolymer at a concentration of 3.0 wt.%, resulting in a 31% incremental oil recovery compared to waterflooding. by injecting guar gum at a concentration of 0.5 wt.%. The RF increased to 54% after the biopolymer injection, resulting in an additional 26% incremental oil recovery compared to water flooding. The study involved the injection of xanthan gum with 3wt% NaCl, which resulted in a total oil recovery of 69.1% and an incremental oil recovery of 30.1% compared to water flooding.
The core flooding results revealed that welan gum produced an additional oil recovery of 7.3% and 25.4% compared to xanthan gum and water flooding, respectively.
Effect of Polymer flooding on residual oil saturation
A machine learning analysis by Zhang (2022) on the effects of wettability and minerals on the distribution of oil residues showed that the sample that was lightly water-wetted to moderately water-wetted showed a higher final recovery rate (81.1% ) as a water-soaked sample (70.2). %). The residual water saturation of the weakly wet to moderately wet sample reached 18.9% after injection of 50 PV of brine (with 20 wt% KI) at an injection rate of 0.03 mL/min, which is similar to the value obtained in this study.
Upscaling the model from the core scale to the field scale
Due to the fact that the field-scale model shares equivalent rock and fluid properties, injection rate, and injection duration with the core-scale model, the recovery factor and pore volume of the injected fluid remain consistent between the two scales, as shown in Figure 23. In addition, the injection rates of the field model are insufficient due to the fact that the water cut profile shows a significant drop from 99.99% during water inundation to approx. 68% after polymer injection, followed by a rapid return to the initial value of 99.99% within three days, which persists until the end of the polymer flood. The high injection rate caused the injected water to move faster than the viscous oil, bypassing the oil phase and resulting in reduced efficiency of the water filling process.
Another adverse effect of high water injection rates is the development of a water cone, where the injected water pushes the oil to the top of the reservoir, forming a cone-shaped structure.
Optimization analysis of the field model on the CMG CMOST
However, in the optimal case, a significant decrease in water injection-related costs has been observed due to the reduction in water injection rate. Consequently, even with a fivefold increase in cash outflow for water injection, the optimal values have generated revenues equivalent to those of the base case. In the 44-day simulation period of the base case, the injected fluid pore volume consists of 36 PV.
The above figure illustrates that in the base case the distribution of oil saturation in the pore spaces becomes disordered at the end of the flooding process.
CONCLUSIONS AND RECOMMENDATIONS
Conclusion
Three different oil trading prices (average, low and high) were considered for revenue and the optimal case was selected with the highest NPV and the lowest water cut rate. In the optimal case, the percentage of water interruption decreased from 95% to 63%, and the recovery factor increased by 13% over water flooding. Furthermore, the reservoir model still has the ability to produce oil as the injected water has not yet completely passed through the reservoir.
This study demonstrates the potential of natural polymer injection of linseed gum as an effective method to enhance oil recovery, which can be applied in the field to maximize production and profitability.
Recommendations for future work
By performing these steps, a comprehensive simulation study can be conducted to evaluate the effectiveness of linseed gum as an EOR method in the specific oil field of interest. The results of this study can provide valuable insights into the potential of Linseed Gum as a practical and sustainable EOR method.
Evaluation of heavy oil recovery factor by water flooding and polymer flooding at different temperatures. An evaluation of the enhanced oil recovery potential of xanthan gum and aquagel in a heavy oil reservoir in Trinidad. Flooding of polymers and its effects on enhanced oil recovery with special reference to Upper Assam Basin.
Linseed gum as a potential stabilizer for CO2-in-water foam in enhanced oil recovery applications.
APPENDICES
