scholarly journals The effectiveness of computed tomography for the experimental assessment of surfactant-polymer flooding

Author(s):  
Fabián Andrés Tapias Hernández ◽  
Rosângela Barros Zanoni Lopes Moreno

The Surfactant-Polymer (SP) process is a type of Chemical Enhanced Oil Recovery (CEOR) method. They are still a challenge for the petroleum oil industry mainly because of the difficulty in designing and forecasting the process behavior on the field scale. Therefore, understanding of the phenomena associated with a CEOR process is of vital importance. For these reasons, this work discusses the benefits of Computed Tomography (CT) uses for the experimental assessment of a SP process. The research includes a literature review that allows identifying the main CT usages for petroleum engineering and a discussion concerning the effectiveness of mathematic expressions proposed for the tomography images treatment of two-phase flow displacement. The conducted experimental methodology can be reproduced to assess the benefits of any chemical Enhanced Oil Recovery (EOR) process with CT. Thus, this paper assesses the conventional waterflooding (WF) and SP flooding as secondary and tertiary oil recovery methods. The developed study allowed us to evaluate through CT images the porosity and the saturation profiles along the rock sample. Also, CT processed data enabled checking the volumetric material balance and determine the oil Recovery Factor (RF). The doubled checked SP data showed an RF increase of 17 and 10 percentage points for secondary and tertiary chemical injection schemes respect to conventional waterflooding. Finally, comparative results of the water cut (Wcut) evidenced the mobility ratio improvement and reduction on the remaining oil saturation.

Energies ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 6520
Author(s):  
Pablo Druetta ◽  
Francesco Picchioni

The traditional Enhanced Oil Recovery (EOR) processes allow improving the performance of mature oilfields after waterflooding projects. Chemical EOR processes modify different physical properties of the fluids and/or the rock in order to mobilize the oil that remains trapped. Furthermore, combined processes have been proposed to improve the performance, using the properties and synergy of the chemical agents. This paper presents a novel simulator developed for a combined surfactant/polymer flooding in EOR processes. It studies the flow of a two-phase, five-component system (aqueous and organic phases with water, petroleum, surfactant, polymer and salt) in porous media. Polymer and surfactant together affect each other’s interfacial and rheological properties as well as the adsorption rates. This is known in the industry as Surfactant-Polymer Interaction (SPI). The simulations showed that optimum results occur when both chemical agents are injected overlapped, with the polymer in the first place. This procedure decreases the surfactant’s adsorption rates, rendering higher recovery factors. The presence of the salt as fifth component slightly modifies the adsorption rates of both polymer and surfactant, but its influence on the phase behavior allows increasing the surfactant’s sweep efficiency.


Geophysics ◽  
2013 ◽  
Vol 78 (5) ◽  
pp. E261-E269 ◽  
Author(s):  
Jeffrey Heenan ◽  
Abigail Porter ◽  
Dimitrios Ntarlagiannis ◽  
Lily Y. Young ◽  
Dale D. Werkema ◽  
...  

The demand for more efficient and economic oil recovery techniques has driven research into novel extraction approaches, including microbial enhanced methods. Microbial enhanced oil recovery (MEOR) is an underutilized technology that could significantly enhance tertiary oil recovery. Previous research has shown the spectral induced polarization (SIP) method to be sensitive to microbial degradation of hydrocarbons, so the method should therefore be sensitive to MEOR treatments. To test this hypothesis, heavy-oil-containing sands were monitored for a period of approximately six months while undergoing MEOR treatment. SIP monitoring showed significant sensitivity to biodegradation induced changes. Increases in phase and imaginary conductivity, with a polarization peak centered on approximately 3–8 Hz, were observed for the two MEOR active columns. Similarly, the normalized chargeability, an integrated parameter of a Debye decomposition analysis of the spectra, showed a linear increase in time. Chromatographic methods confirmed oil biodegradation in the active columns. The SIP responses are likely the result of microbial processes and the changes they promote to oil properties, such as altering wettability, or possibly the effect of organic acid production. The results of this experiment indicate that SIP may be a viable method of monitoring MEOR processes.


1981 ◽  
Vol 103 (4) ◽  
pp. 285-290 ◽  
Author(s):  
K. I. Kamath ◽  
S. J. Yan

The theory of enhanced oil recovery by surfactant flooding (micellarpolymer and “low-tension” floods) is based on three premises: that the chemical slug is 1) less mobile than the crude oil, 2) miscible with the reservoir fluids (oil and brine), and 3) stable over long periods of time (years) in the reservoir environment. We report here a rather simple process in which none of these expensive and exacting requirements have to be met. In this process, relatively small amounts of “EOR-active” substances present in certain petroleum-based sulfonates are found to recover 15–20 percent of the residual oil from waterflooded Berea sandstone cores. The chemicals are injected in the form of slugs of their aqueous solutions. If the chemical slugs are followed with similar slugs of additives such as partially hydrolyzed polyacrylamide, acrylamide monomer, urea, EDTA, or anions such as P2O7‴‴‴‴ and PO4‴‴‴, the oil recovery is increased 30–40 percent of the in-place residual oil. The concentrations of the “active” sulfonate and additive in their respective slugs appear to be of the order of 500 ppm or less. Extrapolation of the laboratory data to field conditions indicate that chemical requirements for the recovery of a barrel of tertiary oil are about 0.5–2 lb of sulfonate and a like amount of additive. The main features of the displacement process are: 1) Oil recovery is independent of oil viscosity in the tested range of 0.4–100 cps. 2) The process is essentially an immiscible displacement in which oil recovery depends on the amount of active chemical in the slug and not its concentration. 3) Tertiary oil is produced in the form of a clean “oil bank” and the buildup of a residual oil saturation at the producing end of linear cores occurs during the flood. From the data on hand, it is apparent that the oil recovery mechanism differs basically in character from the conventional Buckley-Leverett-type immiscible displacement. The low level concentrations of sulfonate and additive involved, and the independence of oil recovery with respect to oil viscosity suggest that the recovery mechanism is possibly actuated by certain specific functional groups in the structure of the EOR-active molecule or its anion, and of the additive. The results hold great potential for developing a simple and economical tertiary oil recovery process that can recover, very substantially, more oil (light as well as moderately viscous) than is now considered possible by conventional chemical floods.


Author(s):  
Mehrdad Sepehri ◽  
Babak Moradi ◽  
Abolghasem Emamzadeh ◽  
Amir H. Mohammadi

Nowadays, nanotechnology has become a very attractive subject in Enhanced Oil Recovery (EOR) researches. In the current study, a carbonate system has been selected and first the effects of nanoparticles on the rock and fluid properties have been experimentally investigated and then the simulation and numerical modeling of the nanofluid injection for enhanced oil recovery process have been studied. After nanofluid treatment, experimental results have shown wettability alteration. A two-phase flow mathematical model and a numerical simulator considering wettability alteration have been developed. The numerical simulation results show that wettability alteration from oil-wet to water-wet due to presence of nanoparticles can lead to 8–10% increase in recovery factor in comparison with normal water flooding. Different sensitivity analyses and injection scenarios have been considered and assessed. Using numerical modeling, wettability alteration process and formation damage caused by entrainment and entrapment of nanoparticles in porous media have been proved. Finally, the net rate of nanoparticles’ loss in porous media has been investigated.


2019 ◽  
Vol 9 (3) ◽  
pp. 186
Author(s):  
Yukie Tanino ◽  
Amer Syed

We designed a hands-on laboratory exercise to demonstrate why injecting an aqueous polymer solution into an oil reservoir (commonly known as “polymer flooding”) enhances oil production. Students are split into three groups of two to three. Each group is assigned to a packed Hele–Shaw cell pre-saturated with oil, our laboratory model of an oil reservoir, and is given an aqueous solution of known polymer concentration to inject into the model reservoir to “push” the oil out. At selected intervals, students record the oil produced, take photos of the cell using their smartphones, and demarcate the invading polymer front on an acetate sheet. There is ample time for students to observe the experiments of other groups and compare the different flow patterns that arise from different polymer concentrations. Students share their results with other groups at the end of the session, which require effective data presentation and communication. Both the in-session tasks and data sharing require team work. While this experiment was designed for a course on Enhanced Oil Recovery for final year undergraduate and MSc students in petroleum engineering, it can be readily adapted to courses on groundwater hydrology or subsurface transport by selecting different test fluids.


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