In Situ Co2 Eor Mechanism and Co2-Oil Phase Behavior

In Situ Co2 Eor Mechanism and Co2-Oil Phase Behavior

ABSTRACT

Numerical reservoir simulators are employed to obtain meaningful and reliable solutions for an actual case due to extreme complexity of the reservoirs systems.

Wilcox formation is a reservoir in the gulf of Mexico with various development challenges, to better maximize the resources in the reservoir, simulation studies is needed to make better informed decision. For this study, a compositional simulator model is developed for comparing CO2 injection in different API oil reservoir.

The fluid samples were characterized using PVT simulator and so also is the swelling factor and the viscosity reduction test.

The E300 eclipse simulator was used for determining the MMP by developing a 1-D slimtube experiment model and a CO2 injection model for the case studied.

The estimated MMP of 6500 psia is less than the reservoir pressure so a miscible flooding was achieved. Four API oil samples (22o , 29o , 38o and 45o ) was simulated and compared considering different scenarios.

TABLE OF CONTENTS

CHAPTER ONE ………1
1.1 Background Study ………..1
1.2 OBJECTIVE OF RESEARCH………….3
1.3 Aims and Objective ………..3
1.4 The outlay of the Thesis…………4
CHAPTER TWO
Literature Review………5
2.1 Geology of deep water Wilcox Formation……………5
2.1.1 Turbidite Elements…….5
2.1.2 Paleogene (Wilcox) Deposition…………………6
2.2 Reservoir Characterization and Development Challenges of Wilcox Formation….7
2.2.1 Reservoir Characterization………..7
2.2.2 Obstacles to Exploration and Development GoM Wilcox Formation……11
2.3 Immiscible CO2 Processes ……….11
2.4 IN SITU CO2 GENERATION …………..13
2.4.1 Ammonium Carbamate as a gas generating agent………..14
2.5 Kinetics and Mechanism of the Reversible Dissociation of Ammonium Carbamate…..19
2.5.2 Urea as a gas generating agent………….27
2.6 TRANSPORT AND STORAGE OF CO2 ……….28
2.6.1 CO2 flooding ………..28
2.6.2 Molecular Diffusion Governed Mass Transport…..29
2.7 Mass Transfer of CO2-Crude Oil Systems…….30
2.7.1 Mass Transfer without Reaction (Physical Absorption)…………34
2.7.1.1 Film Theory ………34
2.7.2 Mass Transfer with Chemical Reaction…………37
2.7.1 Prediction of Diffusion Coefficient………..39
CHAPTER THREE………..40
RESERVOIR SIMULATION MODELING ……….40
3.1 INTRODUCTION TO ECLIPSE 300………40
3.2 Data description and Model used………..40
3.2.1 The phase behavior of the fluid composition ……….41
3.2.2 3-parameter Peng-Robinson Equation of State Model………41
3.3 Estimating Minimum Miscibility Pressure (MMP) ……43
3.4 Urea Reaction and CO2 Generation Kinetics……..44
3.5 CO2 Swelling Factor ……..46
3.5.1 CO2 swelling factor for different API oil ……….46
3.6 CO2-Oil Viscosity Reduction ………..47
3.7 Lohrenz, Bray and Clark Viscosity Reduction Correlation…………48
3.8 Reservoir Model and Rock Properties ………….49
3.8.1 Grid System…………..49
3.8.2 Computational Process…….50
3.8.3 Simulation Model……….50
CHAPTER FOUR ……….52
RESULTS AND DISCUSSION………..52
4.1 Grid sensitivity Analysis. …………52
4.2 Simulation Result and Discussion ……………54
4.3 Sensitivity Analysis…….67
CHAPTER FIVE …………72
CONCLUSIONS AND RECOMMENDATIONS………..72
5.2 Recommendations………73
REFERENCES……….80

 

BACKGROUND STUDY

Only some fraction about (10%) of the initial hydrocarbon in place in a petroleum reservoir can be recovered by primary production using the reservoir’s natural energy drive.

In the turbidite system in the deepwater Wilcox formation of the Northwest Gulf of Mexico, there is a potential of 15Bbbl that covers over 34,000 mi2 (54,740 km2 ) (Meyer, Zarra, Rains, Meltz, & Hall, 2005).

This formation is characterized by high pressure and high temperature and a water depth of 3000-7000 feet, and the formation has an average permeability of about 15mD.

Furthermore, the porosity is about 18%, crude gravity of 250 API, and viscosity of 6cP. The majority of the remaining oil is trapped by capillary forces, bypassed due to reservoir heterogeneity and mobility of the injected fluid to displace reservoir oil.

Therefore, a significant fraction of the remnant oil is available as a target for Enhanced Oil Recovery (EOR) processes.

This oil can be an energy source for years to come. However, as of date, there are new EOR technologies for producing the resource which includes Chemical, Water, Polymer, thermal flooding, and Gas Injection.

REFERENCES

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immiscible and miscible condensate displacements by SC CO2 injection: experimental
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Al-Menhali, A. S., & Krevor, S. (2016). Capillary trapping of CO2 in oil reservoirs: Observations in a
mixed-wet carbonate rock. Environmental science & technology, 50(5), 2727-2734.

Alston, R., Kokolis, G., & James, C. (1985). CO2 minimum miscibility pressure: a correlation for
impure CO2 streams and live oil systems. Society of Petroleum Engineers Journal, 25(02), 268-274.

Altunina, L. K., & Kuvshinov, V. A. (2007). Physicochemical methods for enhancing oil recovery
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Bai, H., & Yeh, A. C. (1997). Removal of CO2 greenhouse gas by ammonia scrubbing. Industrial &
engineering chemistry research, 36(6), 2490-2493.

Bakhtiyarov, S. I., Shakhverdiev, A. K., Panakhov, G. M., & Abbasov, E. M. (2007). Effect of
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Operations Symposium.