scholarly journals An experimental investigation of asphaltene stability in heavy crude oil during carbon dioxide injection

2019 ◽  
Vol 10 (3) ◽  
pp. 919-931 ◽  
Author(s):  
Sherif Fakher ◽  
Mohamed Ahdaya ◽  
Mukhtar Elturki ◽  
Abdulmohsin Imqam
Keyword(s):  
Carbon Dioxide ◽  
Crude Oil ◽  
Pore Size ◽  
Oil Recovery ◽  
Asphaltene Precipitation ◽  
Carbon Dioxide Injection ◽  
Oil Viscosity ◽  
Membrane Pore ◽  
Pore Sizes ◽  
Filter Membrane

Abstract Carbon dioxide (CO2) injection is one of the most applied enhanced oil recovery methods in the hydrocarbon industry, since it has the potential to increase oil recovery significantly and can help reduce greenhouse gases through carbon storage in hydrocarbon reservoirs. Carbon dioxide injection has a severe drawback, however, since it induces asphaltene precipitation by disrupting the asphaltene stability in crude oil that bears even the slightest asphaltene concentration. This can result in severe operational problems, such as reservoir pore plugging and wellbore plugging. This research investigates some of the main factors that impact asphaltene stability in crude oil during CO2 injection. Initially, asphaltene precipitation, flocculation, and deposition were tested using visual tests without CO2 in order to evaluate the effect of oil viscosity and temperature on asphaltene stability and content in the crude oil. The results obtained from the visualization experiments were correlated to the Yen–Mullins asphaltene model and were used to select the proper chemical to alter the oil’s viscosity without strongly affecting asphaltene stability. After performing the visual asphaltene tests, a specially designed filtration vessel was used to perform the oil filtration experiments using filter membranes with a micron and nanometer pore size. The effect of varying CO2 injection pressure, oil viscosity, filter membrane pore size, and filter membrane thickness on asphaltene stability in crude oil was investigated. The results were then correlated with the Yen–Mullins asphaltene model to characterize the asphaltene size within the oil as well. Results showed that as the oil viscosity increased, the asphaltene concentration in the oil also increased. Also, the asphaltene concentration and filter cake thickness increased with the decrease in filter membrane pore size, since the asphaltene particles either plugged up the smaller pores, or the asphaltene nanoaggregates were larger than the pore sizes, and thus the majority of them could not pass. This research studies asphaltene instability in crude oil during CO2 injection in different pore sizes, and correlates the results to the principle of the Yen–Mullins model for asphaltenes. The results from this research can help emphasize the factors that will impact asphaltene stability during CO2 injection in different pore sizes in order to help reduce asphaltene-related problems that arise during CO2 injection in hydrocarbon reservoirs.

A Laboratory Investigation of the Effect of Ethanol-Treated Carbon Dioxide Injection on Oil Recovery and Carbon Dioxide Storage

SPE Journal ◽  
2021 ◽  
pp. 1-17
Author(s):  
Saira ◽  
Emmanuel Ajoma ◽  
Furqan Le-Hussain
Keyword(s):  
Carbon Dioxide ◽  
Oil Recovery ◽  
Carbon Capture ◽  
Molar Fraction ◽  
Co2 Injection ◽  
Carbon Dioxide Injection ◽  
Treated Carbon ◽  
Carbon Dioxide Co2 ◽  
And Storage ◽  
Experimental Runs

Summary Carbon dioxide (CO2) enhanced oil recovery is the most economical technique for carbon capture, usage, and storage. In depleted reservoirs, full or near-miscibility of injected CO2 with oil is difficult to achieve, and immiscible CO2 injection leaves a large volume of oil behind and limits available pore volume (PV) for storing CO2. In this paper, we present an experimental study to delineate the effect of ethanol-treated CO2 injection on oil recovery, net CO2 stored, and amount of ethanol left in the reservoir. We inject CO2 and ethanol-treated CO2 into Bentheimer Sandstone cores representing reservoirs. The oil phase consists of a mixture of 0.65 hexane and 0.35 decane (C6-C10 mixture) by molar fraction in one set of experimental runs, and pure decane (C10) in the other set of experimental runs. All experimental runs are conducted at constant temperature 70°C and various pressures to exhibit immiscibility (9.0 MPa for the C6-C10 mixture and 9.6 MPa for pure C10) or near-miscibility (11.7 MPa for the C6-C10 mixture and 12.1 MPa for pure C10). Pressure differences across the core, oil recovery, and compositions and rates of the produced fluids are recorded during the experimental runs. Ultimate oil recovery under immiscibility is found to be 9 to 15% greater using ethanol-treated CO2 injection than that using pure CO2 injection. Net CO2 stored for pure C10 under immiscibility is found to be 0.134 PV greater during ethanol-treated CO2 injection than during pure CO2 injection. For the C6-C10 mixture under immiscibility, both ethanol-treated CO2 injection and CO2 injection yield the same net CO2 stored. However, for the C6-C10 mixture under near-miscibility,ethanol-treated CO2 injection is found to yield 0.161 PV less net CO2 stored than does pure CO2 injection. These results suggest potential improvement in oil recovery and net CO2 stored using ethanol-treated CO2 injection instead of pure CO2 injection. If economically viable, ethanol-treated CO2 injection could be used as a carbon capture, usage, and storage method in low-pressure reservoirs, for which pure CO2 injection would be infeasible.

scholarly journals Laboratory Studies of Carboniferous Reservoirs of High-Viscosity Oil Fields Using Carbondioxide

2020 ◽  
Vol 20 (4) ◽  
pp. 369-385
Author(s):  
Stanislav A. Kalinin ◽  
◽  
Oleg A. Morozyuk ◽  
Keyword(s):  
Carbon Dioxide ◽  
Heat Carrier ◽  
Oil Recovery ◽  
High Mobility ◽  
High Viscosity ◽  
Laboratory Studies ◽  
Carbon Dioxide Injection ◽  
Recovery Method ◽  
Matrix Blocks ◽  
High Viscosity Oil

It is of current concern for the Permian-Carboniferous reservior of the Usinskoye field to develop low-permeable matrix blocks of carboniferous reservoirs, which contain major reserves of high-viscosity oil. To increase effectiveness of the currently used thermal oil recovery methods, the authors suggest using carbon dioxide as a reservoir stimulation agent. Due to a high mobility in its supercritical condition, СО2 is, theoretically, able to penetrate matrix blocks, dissolve in oil and, additionally, decrease its viscosity. Thus, СО2 applications together with a heat carrier could increase effectiveness of the high-viscosity oil recoveries and improve production parameters of the Permian-Carboniferous reservior of the Usinskoye field. During carbon dioxide injections, including combinations with various agents, some additional oil production is possible due to certain factors. Determination of the influencing factors and detection of the most critical ones is possible in laboratory tests. So, laboratory studies entail the key stage in justification of the technology effectiveness. The paper deals with describing the laboratory facilities and methodologies based on reviews of the best world practice and previous laboratory researches. These aim at evaluating effectiveness of thermal, gas and combined oil recovery enhancement methods. In particular, the authors explore experimental facilities and propose methodology to perform integrated researches of the combined heat carrier and carbon dioxide injection technology to justify the effective super-viscous oil recovery method.

scholarly journals Experimental Study on Reducing CO2–Oil Minimum Miscibility Pressure with Hydrocarbon Agents

Energies ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1975 ◽  
Author(s):  
Junrong Liu ◽  
Lu Sun ◽  
Zunzhao Li ◽  
Xingru Wu
Keyword(s):  
Crude Oil ◽  
Petroleum Ether ◽  
Oil Recovery ◽  
Mass Concentration ◽  
Co2 Flooding ◽  
Oil Viscosity ◽  
Injection Wells ◽  
Boiling Range ◽  
Minimum Miscibility Pressure ◽  
Soluble Surfactants

CO2 flooding is an important method for improving oil recovery for reservoirs with low permeability. Even though CO2 could be miscible with oil in regions nearby injection wells, the miscibility could be lost in deep reservoirs because of low pressure and the dispersion effect. Reducing the CO2–oil miscibility pressure can enlarge the miscible zone, particularly when the reservoir pressure is less than the needed minimum miscible pressure (MMP). Furthermore, adding intermediate hydrocarbons in the CO2–oil system can also lower the interfacial tension (IFT). In this study, we used dead crude oil from the H Block in the X oilfield to study the IFT and the MMP changes with different hydrocarbon agents. The hydrocarbon agents, including alkanes, alcohols, oil-soluble surfactants, and petroleum ethers, were mixed with the crude oil samples from the H Block, and their performances on reducing CO2–oil IFT and CO2–oil MMP were determined. Experimental results show that the CO2–oil MMP could be reduced by 6.19 MPa or 12.17% with petroleum ether in the boiling range of 30–60 °C. The effects of mass concentration of hydrocarbon agents on CO2–oil IFT and crude oil viscosity indicate that the petroleum ether in the boiling range of 30–60 °C with a mass concentration of 0.5% would be the best hydrocarbon agent for implementing CO2 miscible flooding in the H Block.

Asphaltene Deposition Induced by Carbon Oxide and its Influence on Displacement Efficiency

2012 ◽  
Vol 594-597 ◽  
pp. 2451-2454
Author(s):  
Feng Lan Zhao ◽  
Ji Rui Hou ◽  
Shi Jun Huang
Keyword(s):  
Crude Oil ◽  
Oil Recovery ◽  
Carbon Oxide ◽  
Viscosity Reduction ◽  
Core Flooding ◽  
Displacement Efficiency ◽  
Oil Composition ◽  
Oil Viscosity ◽  
Asphaltene Deposition ◽  
Total Oil

CO2is inclined to dissolve in crude oil in the reservoir condition and accordingly bring the changes in the crude oil composition, which will induce asphaltene deposition and following formation damage. In this paper, core flooding device is applied to study the effect of asphaltene deposition on flooding efficiency. From the flooding results, dissolution of CO2into oil leads to recovery increase because of crude oil viscosity reduction. But precipitated asphaltene particles may plug the pores and throats, which will make the flooding effects worse. Under the same experimental condition and with equivalent crude oil viscosity, the recovery of oil with higher proportion of precipitated asphaltene was relatively lower during the CO2flooding, so the asphltene precipitation would affect CO2displacement efficiSubscript textency and total oil recovery to some extent. Combination of static diffusion and dynamic oil flooding would provide basic parameters for further study of the CO2flooding mechanism and theoretical evidence for design of CO2flooding programs and forecasting of asphaltene deposition.

Correlation of Crude Oil Steam Distillation Yields With Basic Crude Oil Properties

1983 ◽  
Vol 23 (06) ◽  
pp. 937-945 ◽  
Author(s):  
Ching H. Wu ◽  
Robert B. Elder
Keyword(s):  
Crude Oil ◽  
Oil Recovery ◽  
Boiling Point ◽  
Steam Distillation ◽  
Recovery Process ◽  
Steam Injection ◽  
Steam Pressure ◽  
Oil Viscosity ◽  
Simulated Distillation ◽  
Distillation Yield

Abstract Steam distillation can occur in reservoirs during steam injection and in-situ combustion processes. To estimate the amount of vaporized oil caused by steam distillation, we established correlations of steam distillation yields with the basic crude oil properties. These correlations were based on steam distillation tests performed on 16 crude oils from various pans of the U.S. The gravity of oils varied from 12 to 40 deg. API [0.99 to 0.83 g/cm3]. The viscosity of oil ranged from 5 to 4,085 cSt [5 to 4085 mm /s] at 100 deg. F [38 deg. C]. The steam distillations were performed at a saturated steam pressure of 220 psia [1.5 MPa]. One oil sample was used in experiments to investigate the effect of steam pressure (220 to 500 psia [1.5 to 3.4 MPa]) on the steam distillation yield. The experiments were carried out to a steam distillation factor (Vw/Voi) of 20, with the factor defined as the cumulative volume of condensed steam used in distillation, Vw, divided by the initial volume of oil, Voi. At a steam distillation factor of 20, the distillation yields ranged from 13 to 57% of the initial oil volume. Several basic crude oil properties can be used to predict steam distillation yields reasonably well. A correlation using oil viscosity in centistokes at 100 deg. F [38 deg. C] can be used to predict the steam distillation yield within a standard error of 4.3 %. The API gravity can be used to estimate wields within 5.6%. A gas chromatographic analysis was made for each crude oil to obtain the component boiling points (simulated distillation temperatures). A correlation parameter was selected from the simulated distillation results that can be used to estimate the steam distillation yields within 4.5%. Introduction Steamflooding has been used commercially to recover heavy oils for several decades. Although it is considered a heavy-oil recovery process, it has been demonstrated to be an effective and commercially feasible process for recovering light oils. To enhance the effectiveness of the oil recovery process, it is important to fully understand and utilize the basic steamflooding mechanisms. Willman et al. investigated the mechanisms of steamflooding. They concluded that oil viscosity reduction, oil volume expansion, and steam distillation are the major mechanisms for oil recovery. Since then, more research has been done on all phases of steam injection. However, steam distillation and its ramifications on recovery have not been quantified fully because of lack of experimental data. Steam distillation can lower the boiling point of a water/oil mixture below the boiling point of the individual components. SPEJ P. 937^

Prediction of Recovery in Unstable Miscible Flooding

1972 ◽  
Vol 12 (02) ◽  
pp. 143-155 ◽  
Author(s):  
E.L. Claridge
Keyword(s):  
Economic Evaluation ◽  
Crude Oil ◽  
Oil Recovery ◽  
Pore Space ◽  
Vertical Direction ◽  
Oil Reservoirs ◽  
Oil Reservoir ◽  
Oil Viscosity ◽  
Recovery Processes ◽  
First Choice

Abstract A new correlation bas been developed for estimating oil recovery in unstable miscible five-spot pattern floods. It combines existing methods of predicting areal coverage and linear displacement efficiency and was used to calculate oil recovery for a series of assumed slug sizes in a live-spot CO2 slug-waterflood pilot test. The economic optimum slug size varies with CO2 cost; at anticipated CO2 costs the pilot would generate an attractive profit if performance is as predicted Introduction Selection of good field prospects for application of oil recovery processes other than waterflooding is often difficult. The principal reason is that other proposed displacing agents are far more costly proposed displacing agents are far more costly than water and usually sweep a lesser fraction of the volume of an oil reservoir (while displacing oil more efficiently from this fraction). Such agents must be used in limited amounts as compared with water; and this amount must achieve an appreciable additional oil recovery above waterflooding recovery. For these reasons, there is in general much less economic margin for engineering error in processes other than waterflooding. The general characteristics of the various types of supplemental recovery processes are well known, and adequate choices can be made of processes to be considered in more detail with respect to a given field. Comparative estimates must then be made of process performance and costs in order to narrow the choice. A much more detailed, definitive process-and-economic evaluation is eventually process-and-economic evaluation is eventually required of the chosen process before an executive decision can be made to commit large amounts of money to such projects. It is in the area between first choice and final engineering evaluation that this work applies. A areal cusping and vertical coning into producing wells. These effects can be seated by existing "desk-drawer" correlation which can confirm or deny the engineer's surmise that he has an appropriate match of recovery process and oil reservoir characteristics is of considerable value in determining when to undertake the costly and often manpower-consuming task of a definitive process-and-economic evaluation. process-and-economic evaluation. An examination of the nature of the developed crude oil resources in the U.S. indicates that the majority of the crude oil being produced is above 35 degrees API gravity and exists in reservoirs deeper than 4,000 ft. The combination of hydrostatic pressure on these oil reservoirs, the natural gas usually present in the crude oil in proportion to this pressure, the reservoir temperatures typically found, and the distribution of molecular sizes and types in the crude oil corresponding to the API gravity results in the fact that, in the majority of cases, the in-place crude oil viscosity was originally no more than twice that of water. A large proportion of these oil reservoirs have undergone pressure decline, gas evolution and consequent increase in crude oil viscosity. However, an appreciable proportion are still at such a pressure and proportion are still at such a pressure and temperature that miscibility can be readily attained with miscible drive agents such as propane or carbon dioxide, and the viscosity of the crude oil is such that the mobility of these miscible drive agents is no more than 50 time s that of the crude oil. Under these circumstances, a possible candidate situation for the miscible-drive type of process may exist. process may exist. Supposing that such a situation is under consideration, the next question is: what specific miscible drive process, and how should it be designed to operate? In some cases, the answer is clear: when the reservoir has a high degree of vertical communication (high permeability and continuity of the permeable, oil-bearing pore space in the vertical direction), then a gravity-stabilized miscible flood is the preferred mode of operation; and the particular drive agent or agents can be chosen on the basis of miscibility requirements, availability and cost. SPEJ P. 143

ROLE OF GEOMICROBIOLOGY IN ENHANCED RECOVERY OF OIL: STATUS QUO

1978 ◽  
Vol 18 (1) ◽  
pp. 161
Author(s):  
B. Bubela
Keyword(s):  
Biological Activity ◽  
Crude Oil ◽  
Oil Recovery ◽  
Field Experiments ◽  
Enhanced Recovery ◽  
Reservoir Rock ◽  
Oil Viscosity ◽  
Reservoir Water ◽  
Composite Effect ◽  
General Terms

The forthcoming decrease in availability of known, presently economical deposits of crude oil in the foreseeable future, makes it imperative that the search for new oil deposits be intensified and the present methods of oil recovery be improved or new ones introduced. From the work reported in the literature it is obvious that microbiology may play a significant role in both cases. Among many parameters influencing oil recovery, viscosity of the oil and the surface tension between the rock, oil and water are of great importance. Microorganisms growing in the reservoir produce gases and surfactants, which may, to some extent, regenerate the endogenous energy of the reservoir and facilitate movement of the crude oil to the well. The composition of the crude oil may become altered by biodegradation of asphaltic, napthenic and/or paraffinic components of the oil. The fraction being biodegraded varies according to the microbiological population present. In general terms mixed populations are more effective in biodegradative processes and production of surfactants. A combination of sewage microorganisms and reservoir microorganisms adapted to 95°C and high pressure, was found satisfactory. Molasses is a suitable supplementary substrate for the growth of such a mixed population. A decrease of viscosity of oil, resulting from biological degradation, may be a composite effect of degradation of highly polymerised hydrocarbons, precipitation of asphaltenes and solution of biologically produced gases in the oil. Such biogenic gases dissolved in the reservoir water may, in combination with biologically produced acids, contribute to the slow solution of the sedimentary rock, thus increasing the rock's permeability and facilitating migration of the oil through the reservoir.The biological activity in the reservoir is influenced by a number of parameters (pH, Eh, temperature, pressure, oil-water dispersion, mineralisation). The permeability of the reservoir rock is of primary importance. Rocks of permeability less than 150 md are not suitable for biologically enhanced recovery. Field tests indicate that biological activity in a reservoir may result in a drop of 50 per cent in the oil viscosity, a three-fold increase of oil production over several months, increase in water acidity and additional production of gas with a recorded pressure increase from 2 atm to 27 atm. The area affected by the biological activity depends on the mineralogy and permeability of the reservoir rock, sandstone and limestone of permeability higher than 600 md being most suitable.Further properly controlled and documented laboratory and field experiments are urgently required before the feasibility of microbiologically enhanced oil recovery can be firmly established.

Carbon Sequestration: an Answer to the World’s Carbon Dioxide Emission Problem

2017 ◽  
Author(s):  
Curtis Wettstein
Keyword(s):  
Carbon Dioxide ◽  
Carbon Sequestration ◽  
Oil Recovery ◽  
Carbon Dioxide Emissions ◽  
Carbon Dioxide Emission ◽  
The United States ◽  
Oil Well ◽  
Carbon Dioxide Injection ◽  
Oil Companies ◽  
Reduce Emissions

As of November 2007, 174 parties had ratified the Kyoto protocol signifying a large part of the solution to one of the worlds primary environmental problems; carbon dioxide emissions. Although the United States refused to sign the protocol, their neighbours in Canada were eager to address the issue and sign. However with oil being a major Canadian export, carbon dioxide emission reduction was arguably improbable and unprofitable. With the pressure of reducing carbon dioxide emissions an imminent, carbon sequestration may be the symbiotic solution in satisfying Kyoto, saving the environment and even increasing profitability. Carbon sequestration is the process where carbon dioxide is injected into an oil well in order to increase recovery. With tertiary oil recoveries driving much of the oil business, cheap and efficient recovery methods are invaluable. Presently there is a Canadian operation in Wayburn, Saskatchewan which employs the technique. In addition, Texas and Scandinavian oil companies are using Carbon dioxide injection. If carbon sequestration increases oil recovery it has to be the preferred method. By purchasing carbon dioxide from external sources and recycling their own, companies can reduce emissions while increasing profits. Finally it may be profitable to save the environment. 

Sign in / Sign up

Export Citation Format

Share Document