Papers by Keyword: Polymer Flooding

Abstract: Polymer flooding, an improved oil recovery technique, is a well-established method for improving oil production. Although numerous polymers have been suggested in the literature, identifying suitable ones for applications in high-temperature and high-salinity carbonate reservoirs remains a challenging task. The viscosity of polymer solutions depends on various parameters, including polymer concentration, temperature, and shear rate. Therefore, screening polymers for these demanding conditions necessitates meticulous experimental work. In this experimental study, polymer solutions' physical property—viscosity—was measured as a function of polymer concentration, temperature, and shear rate. Subsequently, the generated rheological data were used to develop empirical models capable of predicting the viscosity of polymer solutions under various conditions. An acceptable match was achieved between the experimental and model-predicted data. Furthermore, a validation was conducted for the empirical models, yielding a root mean square error of 1.75. These models will significantly reduce the number of experiments required for the screening process and prove valuable for optimization procedures.

Abstract: Polymer flooding has became one of the most important oil recovery technologies with Chinese oilfields coming into tertiary recovery, which lays a solid foundation for high and stable yields in oilfields. But with it’s large-scale industrial production, polymer flooding technology also brings difficulties for the disposal and treatment of polymer flooding wastewater. Compared with conventional water flooding wastewater technology, polymer flooding wastewater not only contains oil but also lots of polymer. “Old three sets” process cannot meet the national discharge standard or the injection water quality standard. Relied on HeNan oilfield united station, this paper studied on the treatment of polymer flooding wastewater, a kind of efficient flocculant was selected for the treatment of polymer flooding wastewater and a set of reasonable technological process was recommended, making the wastewater after disposal meet the injection water quality standard.

Abstract: In this study, local isolated Xanthomonas campestries has been used from local cabbage for xanthan gum production via fermentation in shake flask. The product was then recovered with isopropanol and dried. Meanwhile, for extraction and purification of mushroom polysaccharide, we use dead edible mushroom has been used. Polysaccharide mushroom was extracted with NaOH solutions at 100 ͦ C for 24 hrs. Next, polysaccharide was precipitated separately by the addition of ethanol and the resulting polysaccharide extract were dissolved in distilled water. In the present study, different type of biopolymers was used in order to determine the oil recovery with different concentrations. Biopolymers used in this experiment are xanthan gum and mushroom polysaccharide. The properties of both biopolymers were tested for 3000 ppm and 10000 ppm of concentration. The results shown higher oil recovery factor obtained from the mushroom polysaccharide, which is 84.14%. Meanwhile, the highest recovery obtained by xanthan is about 67.44% only. As a conclusion, increasing polymer concentration will increase the oil recovery factor.

Abstract: At present the development of Daqing Oilfield has entered the water pick-up period, and the polymer separate injection technology for the injection well is urgent needed. However, the difficulty of selecting well and lever for the separate injection of the injection well is relatively large due to the complexity of the Class II reservoir of geological conditions. So for The limits of technology of the geological features, the limits of technology injection of stratified polymer injection for the Class II reservoir provides a scientific basis for the development of oil fields.In this paper, taking Daqing Oilfield Sabei Development Zone as example, establish the mathematical model of polymer flooding. Determine the well and layer selection principles of layered polymer injection wells in the ClassIIreservoir timing. According to the current development situation, give the decrease in water content and the improvement value in recovery under a given measure.Through this paper, we have got production effect of layered polymer injection in the Class II reservoir of Sabei area and given quantified layered polymer injection technology limits.

Abstract: By using polymer solution with high viscosity, polymer flooding can enhance oil recovery by reducing the mobility ratio of displacing fluid and oil in formation. Therefore, the core of polymer flooding's ground transportation is to keep the viscosity of polymer solution unchanged. According to the process layout of polymer ground transportation, the experimental device was designed and manufactured to determine viscosity loss of pipelines and elbow. We obtained the viscosity loss variation law of the polymer solutions of different concentrations at different flow velocities when they flow through the pipeline and elbow. The experimental results showed that the viscosity of polymer solution will decrease after the polymer solution flow through pipelines and elbow, due to the shear effect. The higher the velocity, the more significant the viscosity loss.

Abstract: This paper research the hydrolysis law of BH heat-resistant polymer in distilled water, oil field clear water and oil field waste water, and inspect its long-term thermal stability in the waste water. The results showed that there is few difference about hydrolysis degree between the ZIIordinary polymer and BH heat-resistant polymer in distilled water. BH heat-resistant polymer will hydrolyze faster in the waste water than in the clear water. The hydrolysis degree of different concentrations of BH of polymer solution under the same temperature increases with the increase of aging time, the higher the polymer concentration, the higher the viscosity of the solution, the smaller the hydrolysis degree. BH heat-resistant polymer hydrolysis under high temperature will increase, caused the increase of hydrolysis degree from 95°C to 120°C. AMPS group of BH heat-resistant polymer will not hydrolyze under 95°C.

Abstract: In order to apply the technique of polymer flooding to the offshore oilfield, some contraventions (the large well spacing, the high salinity formation water, the narrow production platform space, the limited load capacity, the slow dissolution of hydrophobically associating polymer, the voluminous existing polymer injection equipment) must be faced. In order to resolve the problems, a study on the efficient polymer dissolving technology for hydrophobically associating polymer flooding on offshore platform was conducted. The principle of polymer rapid dissolution was analyzed on its restrictive factors. By comprehensive utilization of multi-disciplinary angle of studying from polymer materials, fluid mechanics, et al, the efficient polymer dissolving technology was formed by means of compulsory stretching and water logging for polymer molecular chains, and break through the "bottlenecks" of polymer rapid dissolution. The designed dispersing & dissolving equipment cut down the polymer dissolution time from 60 min to 40 min. Meanwhile, the auto-unloading device, metering device, curing system, injection system, and automatic control system were optimized. Compared with the original equipment, the novel one’s occupied area and operating weight decreased by 21% and 37%, respectively. The efficient injection allocation technology was applied to the polymer flooding pilot testing in Bohai bay so as to provide key technology and equipment support for cumulative incremental oil 395×10⁴ m³ (up to June, 2014), incremental output value 12 billion yuan (estimated by the barrel oil price $90).

Abstract: The displacement performance of heat-resistant polymer is evaluated with the artificial cores and natural cores under 95°C. The best concentration of BH heat-resistant polymer is 1500 mg/L, and the best slug is 0.6 PV on the condition of the average permeability is 600×10^-3μm² of the homogeneous core and the oil viscosity is 2.3mPa • s. Under the best concentration and the PV size, BH heat-resistant polymer solution has better displacement effect for the artificial double core whose permeability ratio is less than 4. When permeability ratio exceed 4, the displacement affect no longer increase. When the mobility ratio increase from 0.05 to 0.2, for the artificial cores, the recovery of polymer flooding reduce by 3.17%, and for the natural cores, the recovery of polymer flooding reduce by 2.26%. The recovery of BH polymer that is aged for 90 days after vacuumed is 32.29%. Comparing with the fresh BH polymer, it is lower by 6.56%. That is to say that the aged BH polymer still has good oil displacement efficiency.

Abstract: The experiments on microscopic displacement of flowing gel flooding after water and polymer flooding were carried out with the sand-packing model. The experimental results of the microscopic displacement indicate that oil recovery can be further enhanced using flowing gel after water and polymer flooding, and the enhanced range is about 15 percent. Flowing gel flows preferentially through the largerchannels occupied previously by injected water in flowing gel injection process, improves sweep efficiency of injected water. Because of its viscoelastic, it can be stretched through the narrow pore deformation. The strength was reduced by the shear, dilution, and it would be driven out by the water from the pores and continue to move forward. Therefore, the main function of flowing gel is flooding, while profile modification is temporary effect. Flowing gel flooding can significantly reduce the cost of chemicals. From the development of tertiary oil recovery trend, flowing gel flooding is a technology that is being developed and perfected, with high technology-economic feasibility.

Abstract: Aiming at the design goal of the highest efficiency of the electric submersible pump of polymer flooding and basing on the coordination of the production system of the electric submersible pump well of polymer flooding and taking oil well productivity and parameters of electric submersible pump (displacement, lift, power) of the electric submersible pump as the design parameters, a mathematical model of the optimization design method for the production parameters of the electric submersible pump well of polymer flooding using the nodal system analysis method was established, and through the mathematical model mentioned above, the optimization design method for the production parameters of the electric submersible pump well of polymer flooding was given. The optimization design method mentioned above, taking the electric submersible pump well B1-D4-71 of Daqing Oilfield as an example, was applied. The results indicate that the method mentioned above can make the electric submersible pump work in the high efficiency area after the electric submersible pump well B1-D4-71’s being put into production.