đăng nhập 188bet Potential of CO2-EOR associated with CCS in VietNam

Summary

CO2-EOR has a potential not only in enhancing oil recovery but also in CO2 storage. It is, however, necessary to understand đăng nhập 188bet technical, operational and economic uncertainties by conducting a pilot test for applying CO2-EOR to actual oil fields. This paper describes đăng nhập 188bet methods and procedures to design an inter-well CO2-EOR pilot test and discusses đăng nhập 188bet potential of CO2-EOR in offshore fields, Vietnam.

We devised screening criteria in terms of saturations and reservoir pressure to select locations for pilot tests based on đăng nhập 188bet reservoir model developed and calibrated with đăng nhập 188bet actual field data. đăng nhập 188bet number of pilot wells was determined to be one (1) injection well and two (2) production wells in order to estimate areal sweep efficiency during CO2 injection at a minimum cost. To confirm đăng nhập 188bet effects of CO2-EOR, well interval, cumulative CO2 injection volume and duration were determined to be 300m, 2,000 tons and twoweeks, respectively. đăng nhập 188bet oil production rate began to increase after 1 month from đăng nhập 188bet beginning of đăng nhập 188bet pilot test, and đăng nhập 188bet gas production rate and đăng nhập 188bet vapour phase CO2 mole fraction also began to increase at đăng nhập 188bet same time. Then, đăng nhập 188bet oil production rate reached đăng nhập 188bet peak, which corresponds to oil bank, after 1.5 months from đăng nhập 188bet beginning, and đăng nhập 188bet effect of CO2-EOR was confirmed clearly. If oil saturation is high at đăng nhập 188bet target reservoir, it would be difficult for confirming đăng nhập 188bet oil bank clearly. In such case, pre-water injection before CO2 injection is conducted to reduce đăng nhập 188bet oil saturation at đăng nhập 188bet target reservoir.

In parallel, a CO2 procurement and a new platform were designed through đăng nhập 188bet process optimisation study. Manufactured CO2 was selected as CO2 source for đăng nhập 188bet pilot test due to easy availability andminimumcost. đăng nhập 188bet packedmanufactured CO2 into tank containers was transported to đăng nhập 188bet injection site by trucks and supply vessels. From a CO2 impact study, đăng nhập 188bet potential risks related to corrosion and scale formation can bemanageable by suitable countermeasures such as corrosion resistant alloys (CRAs) and inhibitors.

We also estimated đăng nhập 188bet CO2 volume for storage in đăng nhập 188bet reservoir when CO2 injection was applied. Wefoundabouthalfofthe injected CO2 volume to remain in đăng nhập 188bet reservoir at đăng nhập 188bet normal operational conditions for CO2-EOR. Through this study we proposed a methodology to devise a pilot test plan of CO2-EOR in any offshore, remote oil field.

Key words: CO2-EOR, pre-water injection, CO2 injection.

1. Introduction

Enhanced oil recovery (EOR) by CO2 has a potential not only in enhancing oil recovery but also in CO2 storage. CO2 is a useful agent due to relatively high density and high solubility to crude oils. Because it is expected that sweep efficiency during CO2 injection is better than that in other gases i.e. hydrocarbon gases. It is also expected that miscible displacement by CO2 that enables to achieve high oil recovery is developed more readily in other gases.

In addition, CO2 is one of đăng nhập 188bet greenhouse gasses that address global warming and climate changes. Many efforts have been made to reduce CO2 produced from industrial processes for a decade. Carbon stored underground is an important candidate for preventing CO2 gas from entering đăng nhập 188bet atmosphere. đăng nhập 188bet potent underground is oil and gas reservoirs. This is because đăng nhập 188bet rock caps that are impermeable layer are integrity and đăng nhập 188bet volume is large enough to be stored.

To meet incremental oil recovery and carbon storage, CO2-EOR associated with carbon capture and storage (CCS) has been proposed by many organisations. Similar to applications of CO2-EOR, it is necessary to understand đăng nhập 188bet technical, operational and economic uncertainties by conducting a pilot test to actual oil fields.

đăng nhập 188bet Vietnam Oil and Gas Group (PVN) and JOGMEC conducted an international joint study on a design of inter- well CO2-EOR pilot test at an oil field in Vietnam offshore from 2013 to 2015 in order to understand đăng nhập 188bet applicability of CO2-EOR associated with CCS. đăng nhập 188bet objectives of this study are to understand đăng nhập 188bet CO2 injectivity, vertical sweep and areal sweep efficiency, incremental oil production, injected CO2 volume and cost/risks.

To design đăng nhập 188bet CO2-EOR pilot test, not only subsurface study but also surface study is important to implement a proper and safe operation. When đăng nhập 188bet injected CO2 is produced, potential risks related to CO2 such as corrosion and scale formation on đăng nhập 188bet surface facilities will be increased. This paper describes đăng nhập 188bet subsurface study including uncertainty analysis and countermeasure and đăng nhập 188bet surface study including required CO2 procurement method, optimised surface facility design, and corrosion/ scale formation studies.

2. Subsurface study

Site selection

• Reservoir pressure > 2,600psi
• Oil saturation > 0.2
• Gas saturation = 0

đăng nhập 188bet key factors to screen a pilot area for achieving đăng nhập 188bet miscible displacement are đăng nhập 188bet reservoir pressure in đăng nhập 188bet pilot area. MMP of oil in this field was estimated to be 2,950psig based on đăng nhập 188bet past laboratory studies such as slim-tube test and IFT measurement [1]. To observe đăng nhập 188bet sufficient effects of CO2-EOR, đăng nhập 188bet reservoir pressure during CO2 injection was set over 2,600psi based on đăng nhập 188bet simulation study. A potential hydrocarbon zone was identified by a rule of thumb that porosity multiplied by đăng nhập 188bet oil saturation is 0.05. We assume that đăng nhập 188bet average porosity around đăng nhập 188bet pilot test area is 0.25, thus, đăng nhập 188bet oil saturation is estimated to be 0.2 as a screening criterion. If free gas is liberated in đăng nhập 188bet reservoir, it leads to an undesirable oil displacement. Therefore, đăng nhập 188bet gas saturation is set to 0. Some candidate areas for đăng nhập 188bet pilot test were selected using đăng nhập 188bet criteria.

Thereafter, a certain area was selected as đăng nhập 188bet first option for đăng nhập 188bet following reasons. đăng nhập 188bet selected area is not close to đăng nhập 188bet current producing areas and đăng nhập 188bet large faults which may lead CO2 leaking from đăng nhập 188bet reservoir, and đăng nhập 188bet sufficient incremental oil was clearly estimated to confirm đăng nhập 188bet effects of CO2-EOR based on đăng nhập 188bet reservoir simulation results. Moreover, because đăng nhập 188bet operator has a plan to develop đăng nhập 188bet vicinity of this area, synergy between đăng nhập 188bet development and đăng nhập 188bet pilot test areas in terms of sharing đăng nhập 188bet new platform has been expected.

Base case simulation

We designed a pilot test of CO2-EOR based on a reservoir simulation study. A pilot well configuration was selected to be one injection well and two production wells because of đăng nhập 188bet minimum number of wells in order to understand CO2 areal sweep [4].

Some parameters such as well spacing, CO2 injection rate and total CO2 injection volume were determined based on đăng nhập 188bet sensitivity analysis of reservoir simulation.

For determining these parameters, CO2 utilisation factor (= cumulative incremental oil volume by CO2- EOR/cumulative CO2 injection volume) was used as a performance index. đăng nhập 188bet selected simulation settings for đăng nhập 188bet pilot test are summarised in Figure 1. For maintaining đăng nhập 188bet reservoir pressure, đăng nhập 188bet BHP control value in đăng nhập 188bet production wells is set so that đăng nhập 188bet voidage replacement ratio should be one. To save đăng nhập 188bet required CO2 volume for confirming đăng nhập 188bet effects of CO2-EOR, both injection well and production wells were perforated in đăng nhập 188bet limited zone of reservoir. đăng nhập 188bet horizontal grid was refined to investigate đăng nhập 188bet fluid advancement in detail.

Production profile predicted by reservoir simulation is shown in Figure 2. đăng nhập 188bet oil production rate began to increase 1 month after đăng nhập 188bet beginning of đăng nhập 188bet pilot test. In addition, đăng nhập 188bet gas production rate and đăng nhập 188bet vapour phase CO2 mole fraction also began to increase at đăng nhập 188bet same time. Then, đăng nhập 188bet oil production rate reached đăng nhập 188bet peak after 1.5 months from đăng nhập 188bet beginning, and đăng nhập 188bet effect of CO2-EOR can be confirmed clearly. As a result, đăng nhập 188bet cumulative CO2 injection volume is 36,791Mscf (1,948 tons), and 52.8% amount of CO2 is stored in đăng nhập 188bet reservoir (19,437Mscf, 1,029 tons). We also simulated đăng nhập 188bet stored CO2 with various injection scenarios in đăng nhập 188bet full field. đăng nhập 188bet ratio of đăng nhập 188bet stored CO2 to đăng nhập 188bet injected CO2 during CO2-EOR is around 50% and 80% without and with recycling of produced CO2, respectively. Figure 3 shows đăng nhập 188bet simulation results in đăng nhập 188bet 2nd layer. CO2 sweeps mainly in this layer because đăng nhập 188bet permeability is đăng nhập 188bet highest in đăng nhập 188bet other layers. Reservoir pressure near đăng nhập 188bet injection well is higher than MMP during đăng nhập 188bet simulation period. These simulation outputs also indicate practical aspects of CO2 flooding as follows. đăng nhập 188bet interfacial tension in đăng nhập 188bet CO2 swept area is very low (less than 1.0 dyne/cm). In addition, đăng nhập 188bet oil viscosity in đăng nhập 188bet CO2 swept area except for đăng nhập 188bet vicinity of injection well becomes less than that in đăng nhập 188bet unswept area. Oil saturation is decreased near đăng nhập 188bet injection well, and an oil bank is seen at đăng nhập 188bet downstream side of CO2 front. Residual oil saturation after đăng nhập 188bet pilot test is small (less than 0.1) near đăng nhập 188bet injection well.

Uncertainty analysis

đăng nhập 188bet uncertainties of reservoir characteristic in đăng nhập 188bet pilot test area are relatively high because it is an undeveloped area. For evaluating đăng nhập 188bet uncertainties, based on đăng nhập 188bet previous study [2, 3], sensitivity analysis using reservoir simulation and Monte Carlo simulation was conducted to address đăng nhập 188bet key geological uncertainties which have significant impacts on đăng nhập 188bet pilot performance, and make suitable countermeasures for a successful pilot implementation. In đăng nhập 188bet sensitivity study, six geological parameters involving oil saturation, reservoir pressure, horizontal permeability, Kv/ Kh, Sorw and Sorg were selected. For each parameter, low and high cases were set based on đăng nhập 188bet representative values from đăng nhập 188bet reservoir characteristics. This sensitivity analysis was conducted by changing đăng nhập 188bet parameter one by one while keeping đăng nhập 188bet other parameters same as đăng nhập 188bet base case. Figure 4 shows đăng nhập 188bet sensitivity results for CO2 breakthrough

timing and cumulative production oil volume. đăng nhập 188bet bar chart shows đăng nhập 188bet difference over đăng nhập 188bet base case. If đăng nhập 188bet horizontal permeability or reservoir pressure is lower than đăng nhập 188bet base case, đăng nhập 188bet CO2 breakthrough timing delayed about 1 month. If đăng nhập 188bet oil saturation is higher than đăng nhập 188bet base case, đăng nhập 188bet cumulative oil production volume increases significantly.

Monte Carlo simulation was conducted to estimate đăng nhập 188bet range of pilot performance. In order to apply đăng nhập 188bet Monte Carlo simulation for evaluating đăng nhập 188bet range of đăng nhập 188bet pilot performance, đăng nhập 188bet response surface equation (RSE) and đăng nhập 188bet probability distributions were constructed. đăng nhập 188bet modelling of response surface equation for đăng nhập 188bet cumulative oil production (COP) and đăng nhập 188bet CO2 breakthrough timing (BTT) were conducted based on đăng nhập 188bet regression of đăng nhập 188bet sensitivity analysis results. đăng nhập 188bet following equations were modelled as a function of geological uncertainties.

Figure 5 showsthecorrelationsbetweentheprediction results by RSE and đăng nhập 188bet reservoir simulation output. đăng nhập 188bet figure suggests that đăng nhập 188bet predicted value by RSE is high correlation with that of đăng nhập 188bet reservoir simulation.Figure 6 shows representative probability distributions of đăng nhập 188bet geological parameters in đăng nhập 188bet pilot area based on đăng nhập 188bet simulation model. Figure 7 shows đăng nhập 188bet output of Monte Carlo simulation for CO2 breakthrough timing and cumulative oil recovery for each probability. It is predicted that more than 41,000bbl oil will be recovered with 90% probability. In other words, đăng nhập 188bet probability to be less than 41,000bbl is only 10%. Those results depend on đăng nhập 188bet assumed probability distribution significantly. Table 1 shows đăng nhập 188bet estimated geological parameters for each probability based on đăng nhập 188bet most likely scenario.

đăng nhập 188bet pilot production performance for each probability was predicted by reservoir simulation based on đăng nhập 188bet estimated geological parameters. Figure 8 shows đăng nhập 188bet oil production rate and CO2 concentration in production gas for P10, P50 and P90 cases, respectively. đăng nhập 188bet left figures show đăng nhập 188bet prediction results of đăng nhập 188bet base

case. They indicate a wide range of đăng nhập 188bet performance. It means that pilot production performance has a high uncertainty. Furthermore, it is found that đăng nhập 188bet incremental oil production is not confirmed clearly in P10 case because of đăng nhập 188bet shortage of CO2 injection volume over đăng nhập 188bet large amount of oil in đăng nhập 188bet reservoir.

Countermeasure for successful pilot test

If a large amount of CO2 can be prepared, we will confirm đăng nhập 188bet oil bank readily even in P10 case. CO2 procurement volume is, however, limited in đăng nhập 188bet offshore field.We consider pre-water injection before CO2 injection as an effective countermeasure for a successful pilot test implementation. đăng nhập 188bet right figures in Figure 8 show đăng nhập 188bet prediction results based on đăng nhập 188bet base case scenario plus pre-water injection for 5 months. If pre-water injection is applied, not only đăng nhập 188bet range of uncertainty decreases but also incremental oil by CO2-EOR is confirmed readily. If đăng nhập 188bet actual oil saturation is higher than đăng nhập 188bet expected oil saturation around đăng nhập 188bet newly drilled pilot wells, đăng nhập 188bet pre-water injection will be conducted for understanding đăng nhập 188bet effects of CO2-EOR.

3. Surface study

CO2 procurement

We purchase liquefied CO2 which is đăng nhập 188bet enough CO2 volume required for CO2-EOR pilot test from đăng nhập 188bet supplier.

It is assumed that liquefied CO2 in đăng nhập 188bet tank containers is transported to đăng nhập 188bet offshore platform by trucks and vessels. Manufactured CO2 is filled up into đăng nhập 188bet tank containers and carried by trucks to temporary storage area in đăng nhập 188bet nearby port. đăng nhập 188bet tank containers are moved to đăng nhập 188bet supply vessels on đăng nhập 188bet sea and transported to đăng nhập 188bet pilot test area.

Surface facility design

Because đăng nhập 188bet pilot test area is undeveloped, it is necessary to build a new platform for đăng nhập 188bet pilot test as well as treatment of production liquid, water injection and gas lift pipeline. As shown in Figure 9, liquid CO2 supplied from a supply vessel is send to đăng nhập 188bet injection pump through đăng nhập 188bet CO2 header, and injected into đăng nhập 188bet reservoir from injection well via heater. Liquid CO2 heater is to prevent cracking of pipe and degradation of equipment materials. Injection water is supplied from đăng nhập 188bet existing platform when water is injected after CO2 injection. đăng nhập 188bet volume of produced gas and liquid from each production well is measured with đăng nhập 188bet test separator.

CO2 breakthrough impact

đăng nhập 188bet CO2 impact study for all đăng nhập 188bet related facilities was conducted and divided into đăng nhập 188bet following steps:

- Process simulation for all đăng nhập 188bet related facilities;

- Corrosion and scaling formation estimation study for đăng nhập 188bet related facilities;
- Material selection study based on process simulation and estimation results of corrosion and scaling formation.

Process simulation has been conducted to confirm how much CO2 is distributed to đăng nhập 188bet related facilities. Corrosion rates and scaling formation potentials were estimated with a corrosion/electrolyte/scaling simulator, based on a “new fresh” carbon steel corroding surface.

Corrosion

Figure 10 shows đăng nhập 188bet total predicted corrosion amount for each production equipment/flowline for carbon steel, for đăng nhập 188bet duration of đăng nhập 188bet CO2-EOR project life. It was calculated by integrating đăng nhập 188bet corrosion rate for each time. It shows that there is a very high total corrosion of 1.3mm of đăng nhập 188bet production well tubulars downhole, with a reduced total corrosion of 0.31mm at đăng nhập 188bet production wellhead once combined with lift gas, which further reduces to 0.28mm once combined

with đăng nhập 188bet produced fluids from other well at đăng nhập 188bet inlet to đăng nhập 188bet flowline. đăng nhập 188bet high predicted total corrosion depth for đăng nhập 188bet well tubulars over đăng nhập 188bet duration of đăng nhập 188bet CO -EOR project for carbon steel is not deemed acceptable. It is noted that total corrosion of 1.35mm is predicted at đăng nhập 188bet hydrocarbon gas compressor if đăng nhập 188bet carbon steel is used. As high corrosion resistance alloy is used, đăng nhập 188bet actual total amount of this equipment should become smaller and be negligible. Scaling
đăng nhập 188bet predicted potential of BaSO4 and CaCO3 scales in đăng nhập 188bet production system is presented in Figure 11.

This shows how đăng nhập 188bet scale potential changes through đăng nhập 188bet process, for đăng nhập 188bet baseline simulation (before CO2 breakthrough) and đăng nhập 188bet predicted peak breakthrough of CO2. Only đăng nhập 188bet 2 cases have been plotted as đăng nhập 188bet extreme cases. All of đăng nhập 188bet simulated scale formation potentials for BaSO4 in đăng nhập 188bet production process train are less than 2mg/L,

and so are manageable by suitable scale inhibitors. đăng nhập 188bet breakthrough of CO2 into đăng nhập 188bet production wells eliminates đăng nhập 188bet scaling formation potential of CaCO3 in đăng nhập 188bet front end of đăng nhập 188bet production process train from đăng nhập 188bet new well bottoms through to đăng nhập 188bet inlet to đăng nhập 188bet 1st heater inlet. This is probably due to đăng nhập 188bet addition of CO2, shifting đăng nhập 188bet pH of đăng nhập 188bet produced fluids downwards (more acidic conditions) and therefore keeping đăng nhập 188bet scaling ions in solution. With CO2 breakthrough, there is an increase in scaling potential of CaCO3 at đăng nhập 188bet outlet of đăng nhập 188bet 1st heater, but this level of CaCO3 scale is manageable by a suitable scale inhibitor. At đăng nhập 188bet water outlet of đăng nhập 188bet 2nd separator and all vessels downstream, there is very little change in đăng nhập 188bet scaling potential for CaCO3, with only a 10% increase in đăng nhập 188bet predicted amount of CaCO3 scale from đăng nhập 188bet baseline simulation to đăng nhập 188bet predicted peak breakthrough of CO2. This level of scale increase can easily be managed through đăng nhập 188bet existing scale inhibitors used in this oil field.

đăng nhập 188bet predicted scale formation potential for đăng nhập 188bet produced water handling system is presented by scale type in Figure 12. It does not change significantly from đăng nhập 188bet baseline simulation to đăng nhập 188bet predicted peak breakthrough of CO2. This level of scale in đăng nhập 188bet produced water handling system can be easily managed through đăng nhập 188bet existing scale inhibitors used in this oil field.

Material selection

Corrosion rate simulation was made using high corrosionresistancealloysasindicatedbelowtodetermine their suitability:

• 13Cr steel alloy;
• Stainless steel 316;
• Duplex stainless 2205;

đăng nhập 188bet simulated corrosion rates across đăng nhập 188bet process for these higher steel grades are presented in Figure 13. It is seen that all of đăng nhập 188bet corrosion simulated high corrosion resistance alloys offer a vast improvement in đăng nhập 188bet corrosion rate in đăng nhập 188bet case of CO2 concentration peak. đăng nhập 188bet corrosion rate at đăng nhập 188bet well bottom for carbon steel at 10.37mm/year reduces to < 0.03mm/year when 13Cr steel alloy is used. This decrease in corrosion rate indicates đăng nhập 188bet permissible corrosion limits that can be easily managed through đăng nhập 188bet use of corrosion inhibitors. đăng nhập 188bet corrosion rate can be further reduced through đăng nhập 188bet use of either stainless steel 316 or duplex stainless 2205, as has been used in some oil fields to successfully mitigate corrosion. It should be noted that both stainless steel 316 and duplex stainless 2205 are very expensive for oil field process equipment. 

Mitigation plan

đăng nhập 188bet mitigation plan for corrosion risk and scale formation risk is summarised in Figure 14. It is quite evident that in đăng nhập 188bet case of CO2 concentration peak đăng nhập 188bet well completions in carbon steel are not appropriate. It is said that 13Cr steel alloy has typically been used for high CO2 gas wells. Stainless steel 316 appears to have a higher corrosion resistance than 13Cr steel alloy. It will, however, be prone to chloride stress corrosion cracking in higher temperature environments > 50°C in đăng nhập 188bet presence of chloride ions. Duplex 2205 should provide even better corrosion resistance, but with very significant cost rise. đăng nhập 188bet use of 13Cr steel alloy is suitable for đăng nhập 188bet new production wells. It is effective to use also a variety of corrosion and scale inhibitors. As for test separator that will be installed on đăng nhập 188bet pilot test platform, lining inside đăng nhập 188bet separator by polymers such as polyethylene resin is desirable because fluid containing high CO2 concentration will flow into đăng nhập 188bet separator although CO2 partial pressure decreases compared to wellhead and well bottom. In addition, it is necessary that regular pigging of đăng nhập 188bet subsea flowlines and flaring of đăng nhập 188bet associated produced gas at đăng nhập 188bet pilot test platform reduce đăng nhập 188bet corrosion potential in đăng nhập 188bet topside process equipment and flowlines.

4. Conclusions

đăng nhập 188bet CO2-EOR inter-well pilot test in đăng nhập 188bet offshore oil field was designed to achieve đăng nhập 188bet aim in all situations as follows;

• đăng nhập 188bet number of pilot well is determined to be 1 injection well and 2 production wells because of đăng nhập 188bet minimum number of wells in order to estimate CO2 areal effective countermeasure.
• To reduce đăng nhập 188bet procurement cost of required CO2 for đăng nhập 188bet pilot test, CO2 was determined to be secured from a CO2 manufactory.
• New platform was designed through đăng nhập 188bet process optimisation study.
• There will be increased potential risk of corrosion and scale formation. đăng nhập 188bet high predicted total corrosion depth for đăng nhập 188bet well tubulars over đăng nhập 188bet duration of đăng nhập 188bet CO2- EOR project for carbon steel is not deemed acceptable, so đăng nhập 188bet use of CRA’s in đăng nhập 188bet production wells are essential. In addition, inside lining at đăng nhập 188bet test separator, pigging and corrosion/scale inhibitors are necessary.

When đăng nhập 188bet CO2-EOR pilot test will be planned in any oil field, it will be possible to make đăng nhập 188bet test design with đăng nhập 188bet same procedure as this study.

Acknowledgements

This study was implemented as a part of đăng nhập 188bet joint study between đăng nhập 188bet Vietnam Oil and Gas Group (PVN) and JOGMEC, financially supported by đăng nhập 188bet Ministry of Economy, Trade and Industry (METI) in Japan. We would like to thank Petrovietnam and METI for providing permission to publish this paper.

References

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• We also simulated đăng nhập 188bet stored CO2 with various injection scenarios in đăng nhập 188bet full field. đăng nhập 188bet ratio of đăng nhập 188bet stored CO2 to đăng nhập 188bet injected CO2 during CO2-EOR is around 50% and 80% without and with recycling of produced CO2, respectively.
• Uncertainty analysis indicates that there is a possibility đăng nhập 188bet oil bank becomes smeared if đăng nhập 188bet oil saturation is high. For confirming đăng nhập 188bet effect of CO2-EOR clearly, pre-water injection before CO2 injection is an

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3. Ali Rawahi, Hafez H.Hafez, Arafat Al-Yafei, Saleem G.Ghori, Kevin L.Putney, Timonthy R.Matthews. Maximize đăng nhập 188bet ultimate recovery by designing and optimising a CO2 miscible gas injection pilot in a giant carbonate oil reservoir, Abu Dhabi. International Petroleum Conference and Exhibition, Abu Dhabi, UAE. 11 - 14 November, 2012.

4. Gary F.Teletzke, Robert C.Wattenbarger, John R.Wilkinson. Enhanced oil recovery pilot testing best practices. SPE Reservoir Evaluation & Engineering. 2010; 13(1).