scholarly journals Studies on a Foam System of Ultralow Interfacial Tension Applied in Daqing Oilfield after Polymer Flooding

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Hong-sheng Liu ◽  
Jing-qin Wang ◽  
Li Yang ◽  
Dong-yang Jiang ◽  
Chang-sen Lv ◽  
...  

In order to study the effects of oil displacement by a foam system of ultralow interfacial tension, the interfacial activities and foam properties of a nonionic gemini surfactant (DWS) were investigated under Daqing Oilfield reservoir conditions. Injection methods and alternate cycle of the foam system were discussed here on the basis of results from core flow experiments. It was obtained that the surface tension of DWS was approximately 25 mN/m, and ultralow interfacial tension was reached between oil and DWS with a surfactant concentration between 0.05wt% and 0.4wt%. The binary system showed splendid foam performances, and the preferential surfactant concentration was 0.3wt% with a polymer concentration of 0.2wt%. When gas and liquid were injected simultaneously, flow control capability of the foam reached its peak at the gas-liquid ratio of 3 : 1. Enhanced oil recovery factor of the binary foam system exceeded 10% in a parallel natural cores displacement after polymer flooding.

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1046 ◽  
Author(s):  
Saeed Akbari ◽  
Syed Mohammad Mahmood ◽  
Hosein Ghaedi ◽  
Sameer Al-Hajri

Copolymers of acrylamide with the sodium salt of 2-acrylamido-2-methylpropane sulfonic acid—known as sulfonated polyacrylamide polymers—had been shown to produce very promising results in the enhancement of oil recovery, particularly in polymer flooding. The aim of this work is to develop an empirical model through the use of a design of experiments (DOE) approach for bulk viscosity of these copolymers as a function of polymer characteristics (i.e., sulfonation degree and molecular weight), oil reservoir conditions (i.e., temperature, formation brine salinity and hardness) and field operational variables (i.e., polymer concentration, shear rate and aging time). The data required for the non-linear regression analysis were generated from 120 planned experimental runs, which had used the Box-Behnken construct from the typical Response Surface Methodology (RSM) design. The data were collected during rheological experiments and the model that was constructed had been proven to be acceptable with the Adjusted R-Squared value of 0.9624. Apart from showing the polymer concentration as being the most important factor in the determination of polymer solution viscosity, the evaluation of the model terms as well as the Sobol sensitivity analysis had also shown a considerable interaction between the process parameters. As such, the proposed viscosity model can be suitably applied to the optimization of the polymer solution properties for the polymer flooding process and the prediction of the rheological data required for polymer flood simulators.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Ru-Sen Feng ◽  
Yong-Jun Guo ◽  
Xin-Min Zhang ◽  
Jun Hu ◽  
Hua-Bing Li

Hydrophobically modified associating polyacrylamide (HAPAM) has good compatibility with the Daqing heavy alkylbenzene sulfonate surfactant. The HAPAM alkali/surfactant/polymer (ASP) system can generate ultralow interfacial tension in a wide range of alkali/surfactant concentrations and maintain stable viscosity and interfacial tension for 120 days. The HAPAM ASP system has good injectivity for the Daqing class II reservoirs (100–300 × 10−3 μm2) and can improve oil recovery by more than 25% on top of water flooding. In the presence of both the alkali and the surfactant, the surfactant interacts with the associating groups of the polymer to form more micelles, which can significantly enhance the viscosity of the ASP system. Compared with using HPAM (Mw = 2.5 MDa), using HAPAM can reduce the polymer use by more than 40%.


2020 ◽  
Vol 20 (6) ◽  
pp. 1382
Author(s):  
Tengku Amran Tengku Mohd ◽  
Shareena Fairuz Abdul Manaf ◽  
Munawirah Abd Naim ◽  
Muhammad Shafiq Mat Shayuti ◽  
Mohd Zaidi Jaafar

Polymer flooding could enhance the oil recovery by increasing the viscosity of water, thus, improving the mobility control and sweep efficiency. It is essential to explore natural sources of polymer, which is biologically degradable and negligible to environmental risks. This research aims to produce a biodegradable polymer from terrestrial mushroom, analyze the properties of the polymer and investigate the oil recovery from polymer flooding. Polysaccharide biopolymer was extracted from mushroom and characterized using Fourier Transform Infrared Spectrometer (FTIR), while the polymer viscosity was investigated using an automated microviscometer. The oil recovery tests were conducted at room temperature using a sand pack model. It was found that polymer viscosity increases with increasing polymer concentration and decreases when increase in temperature, salinity, and concentration of divalent ions. The oil recovery tests showed that a higher polymer concentration of 3000 ppm had recovered more oil with an incremental recovery of 25.8% after waterflooding, while a polymer concentration of 1500 pm obtained incremental 22.2% recovery of original oil in place (OOIP). The oil recovery from waterflooding was approximately 25.4 and 24.2% of the OOIP, respectively. Therefore, an environmentally friendly biopolymer was successfully extracted, which is potential for enhanced oil recovery (EOR) application, but it will lose its viscosity performance at certain reservoir conditions.


Author(s):  
Oluwaseun Taiwo ◽  
Kelani Bello ◽  
Ismaila Mohammed ◽  
Olalekan Olafuyi

Surfactant flooding, a chemical IOR technique is one of the viable EOR processes for recovering additional oil after water flooding. This is because it reduces the interfacial tension between the oil and water and allows trapped oil to be released for mobilization by a polymer.In this research, two sets of experiments were performed. First, the optimum surfactant concentration was determined through surfactant polymer flooding using a range of surfactant concentration of 0.1% to 0.6% and 15% of polymer. Secondly, another set of experiments to determine the optimum flow rate for surfactant flooding was carried out using the optimum surfactant concentration obtained. Lauryl Sulphate (Sodium Dodecyl Sulphate, SDS), an anionic surfactant, was used to alter the interfacial tension and reduce capillary pressure while Gum Arabic, an organic adhesive gotten from the hardened sap of the Acacia Senegal and Acacia Seyal trees, having a similar molecular structure and chemical characteristics with Xanthan Gum, was the polymer used to mobilize the oil.The results show that above 0.5%, oil recovery decreases with increase in concentration such that between 0.5 and 0.6%, a decrease of (20% -19%) is recorded. This suggests that it would be uneconomical to exceed surfactant concentration of 0.5%. It is shown in the result of the first set of experiments that a range of oil recovery of 59% to 76% for water flooding and a range of 11.64% to 20.02% additional oil recovery for surfactant Polymer flooding for a range of surfactant flow rate of surfactant concentration of 0.1% to 0.6%. For the second sets of experiments, a range of oil recovery of 64% to 68% for water flooding and a range of 15% to 24% additional oil recovery for surfactant flooding for a range of surfactant flow rate of surfactant flow rate of 1cc/min to 6cc/min. The Optimum surfactant flow rate resulting in the highest oil recovery for the chosen core size is 3cc/min. It's highly encouraged that the critical displacement rate is maintained to prevent the development of slug fingers.In summary, an optimum Surfactant flow rate is required for better performance of a Surfactant flooding.


2013 ◽  
Vol 807-809 ◽  
pp. 2607-2611
Author(s):  
Byung In Choi ◽  
Moon Sik Jeong ◽  
Kun Sang Lee

Water salinity and hardness have been regarded as main limitation for field application of polymer floods. It causes not only reduction of polymer concentration, but also injectivity loss in the near wellbore. Based on the mathematical and chemical theory, extensive numerical simulations were conducted to investigate performance of polymer floods in the high-salinity reservoirs. According to results from simulations, the high salinity reduces the viscosity of polymer in contacting area. That causes a poor sweep efficiency of polymer flooding. Moreover, the presence of divalent cations makes the project of polymer flooding worse. That is because of excessively increased bottom-hole pressure in injection well by the precipitation of polymer. The quantitative assessment of polymer floods needs to be required before field application. Therefore, the results in this paper are helpful for optimal polymer flooding design under harsh reservoir conditions.


2021 ◽  
pp. 91-107
Author(s):  
E. A. Turnaeva ◽  
E. A. Sidorovskaya ◽  
D. S. Adakhovskij ◽  
E. V. Kikireva ◽  
N. Yu. Tret'yakov ◽  
...  

Enhanced oil recovery in mature fields can be implemented using chemical flooding with the addition of surfactants using surfactant-polymer (SP) or alkaline-surfactant-polymer (ASP) flooding. Chemical flooding design is implemented taking into account reservoir conditions and composition of reservoir fluids. The surfactant in the oil-displacing formulation allows changing the rock wettability, reducing the interfacial tension, increasing the capillary number, and forming an oil emulsion, which provides a significant increase in the efficiency of oil displacement. The article is devoted with a comprehensive study of the formed emulsion phase as a stage of laboratory selection of surfactant for SP or ASP composition. In this work, the influence of aqueous phase salinity level and the surfactant concentration in the displacing solution on the characteristics of the resulting emulsion was studied. It was shown that, according to the characteristics of the emulsion, it is possible to determine the area of optimal salinity and the range of surfactant concentrations that provide increased oil displacement. The data received show the possibility of predicting the area of effectiveness of ASP and SP formulations based on the characteristics of the resulting emulsion.


Processes ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 176 ◽  
Author(s):  
Yangang Bi ◽  
Zhi Tan ◽  
Liang Wang ◽  
Wusong Li ◽  
Congcong Liu ◽  
...  

Polymer flooding emulsions and microemulsions caused by tertiary oil recovery technologies are harmful to the environment due to their excellent stability. Two cationic hyperbranched polyamidoamines (H-PAMAM), named as H-PAMAM-HA and H-PAMAM-ETA, were obtained by changing the terminal denotation agents to H-PAMAM, which was characterized by 1H NMR, FT-IR, and amine possession, thereby confirmed the modification. Samples (300 mg/L) were added to the polymer flooding emulsion (1500 mg/L oil concentration) at 30 °C for 30 min and the H-PAMAM-HA and H-PAMAM-ETA were shown to perform at 88% and 91% deoil efficiency. Additionally, the increased settling time and the raised temperature enhanced performance. For example, an oil removal ratio of 97.7% was observed after dealing with the emulsion for 30 min at 60 °C, while 98.5% deoil efficiency was obtained after 90 min at 45 °C for the 300 mg/L H-PAMAM-ETA. To determine the differences when dealing with the emulsion, the interfacial tension, ζ potential, and turbidity measurements were fully estimated. Moreover, diametrically different demulsification mechanisms were found when the samples were utilized to treat the microemulsion. The modified demulsifiers showed excellent demulsification efficiency via their obvious electroneutralization and bridge functions, while the H-PAMAM appeared to enhance the stability of the microemulsion.


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