Property evaluation and application of polyacrylamide for oil displacement

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2016-03-05 06:00:53

Polymer flooding in Daqing oilfield is mainly used for partially hydrolyzed polyacrylamide HPAM. It is generally believed that polyacrylamide can play an important role in mediating the rheological properties of the injected water, increasing the viscosity of the driving fluid, improving the efficiency of water flooding and so on. However, due to the difference of the content of ionic composition and content in the underground water, the molecular shape and molecular weight of the media are not the same. The comprehensive performance of polyacrylamide products will directly affect the quality of technical and economic effects of polymer flooding. Completely follow the conventional polymer eleven physicochemical properties index evaluation method has been unable to effectively identify and evaluate a variety of polymer products suitable for Daqing oilfield. Due to the ultra high molecular weight polymer and low molecular weight salt resistant polymer and other new polymer functional groups introduced into the molecule chain, compared with the conventional polymer, its solution properties appeared significant change. The resulting accuracy decreased and the adaptability of conventional detection method of variation.

The main purpose of this project is through static light scattering of polyacrylamide (PAM) and hydrolyzed polyacrylamide (HPAM) molecular weight test absolute method, based on research solution ion micro environment and field environment of poly acrylamide molecular size and GPC light scattering on-line detection of polymer molecular weight distribution of feasibility, and study the properties of different structure of aqueous polymer solutions. The main contents include: Light Scattering Determination of experimental conditions and evaluation of viscosity measurement results; effect of ion concentration in the solution of molecular dimensions, the second virial coefficient; explore the polymer solution of the theta condition; GPC light scattering combined with of injected and produced fluid in the polymer molecular weight distribution of evaluation. Low molecular weight polyacrylamide filter factors are mostly to meet the criteria of the original standard, so it does not make adjustments. For ultra high molecular weight polyacrylamide filtering factor index properly prevent wide, according to the research results, we believe that the polymer molecular weight between 1600 - 1900 million filter factor is relaxed to 3.0 is appropriate, 19 million is not defined for the molecular weight above. In different periods, different types (including hydrophobically associating polymer, ultra high molecular weight salt resistant polymer, low molecular weight salt resistant polymers, etc.) of the model salt resistant polymer products carried out solid content, shear 47 WP=53 Jilin University Master Thesis flooding by polyacrylamide of quality evaluation and application of viscosity retention rate of eleven physicochemical performance evaluation index, and with Daqing in molecular weight polymers for the performance comparison and the initial formulation of the a flooding with new high salt polymer performance requirements and test methods. Combined with advanced techniques such as infrared spectroscopy, mass spectrometry, chromatography and light scattering, the structure composition of various polymers were analyzed qualitatively, and the influence of structure composition on the properties of the solution was found. Then, according to the actual needs of the research and put forward a high degree of accuracy, wide range of detection methods. Through the comprehensive evaluation of different polymers, including physical and chemical properties, salt resistance, shear resistance, stability, resistance coefficient and residual resistance coefficient, the experimental results of core flooding, etc.. A new polymer product which is suitable for the preparation of polymer flooding is selected. The optimized salt resistant polymer showed good physical and chemical properties, salt resistance, shear resistance, viscoelasticity, stability and good performance in the laboratory. Salt resistance of ultra high molecular weight polymer molecules in the water and sewage has network structure, with the preparation of polymer solution with good elastic and high oil displacement effect, show that the molecular structure of mesh is beneficial to improving the viscoelasticity of polymer solution. Associating polymer and the molecular weight of polymer, the molecules in the aqueous solution dissolving and dispersing, the viscosity of the system does not like molecular weight polymer viscosity that quickly tends to a constant, but with the extension of time and gradually increased, the reason is intermolecular by associating need some time. In order to better utilization of sewage and high calcium and magnesium in water for preparation of low molecular weight salt resistant polymer, improvement in low permeability layer of polymer flooding oil effect, carried out, including physical and chemical properties, sewage system viscosity, flow properties, core flooding results, rheology characteristics and visco elastic, the comprehensive performance of indoor work, preliminary screening the two small field test test products at present, flooding with polymer performance index is more, it is necessary to accurately distinguish what characteristics are conducive to the actual displacement. Firstly, the different polymers should carry out comprehensive performance evaluation, evaluate the environmental conditions should be as far as possible with the field maintain a consistent, combined with multi core to simulate the whole flooding oil test results, of different polymers proposed main characteristic indexes and auxiliary performance index. Secondly, the single well and well group which is close to the geological condition are selected to inject different polymer, and the effect of different characteristic indexes on the effect of the actual displacement is further verified by the field application effect. 48 WP=54 master's thesis of Jilin University flooding polyacrylamide property evaluation and application of short before has yet to establish a unified and effective comprehensive performance evaluation method, the qualitative study of new polymer should be to drive performance of oil (oil displacement efficiency, liquidity and shunt steering, and compatibility of reservoir).

Polyacrylamide (PAM) and its derivatives has been applied in oil, water treatment, paper making, mineral processing, and other fields, uses a wide range of water soluble polymer, as the paper with additives, adhesives, leather retanning agent and flocculant and filter loss reducing agent. Added crosslinking agent PAM polymer has excellent swelling, water and water performance, as "diapers" material, soil water holding agent, oil field water plugging agent. So the research of this paper has a good practical value and broad application prospects. In this paper, we study the synthesis of core-shell structure polyacrylamide polymer, core-shell structure of PAM derivatives than ordinary PAM derivatives have better performance. In this paper, through of monomer, emulsifier system, trigger system, temperature and other factors in the regulation of, control of polymer emulsion stability and monomer conversion and by transmission electron microscopy (TEM) and scanning electron microscopy (SEM) characterization of polymer microspheres morphology; at the same time the also to PAM derivatives by infrared spectroscopy, solid content, degree of hydrolysis, intrinsic viscosity, swelling ratio, the glass transition temperature (TG), plugging performance of determination. Polyacrylamide (PAM) polymer was synthesized by inverse emulsion polymerization with acrylamide as the main body. The best conditions for the stability of polymer emulsion are discussed, including the reaction temperature, the heating method, the oil phase dispersion method, the type of emulsifier and the amount of the emulsifier. Then the single factor experiment, the effects of initiator agent, acrylamide content, 2 - methyl - 2 - acrylamido propane sulfonic acid dosage, crosslinking agent on the monomer conversion rate of polymer microspheres and the swelling of the effect of, and to determine the optimal conditions of polymer emulsion polymerization. Finally, the best experimental conditions are verified by the parallel experiment of the optimal conditions, and the monomer conversion rate is maintained at more than 90%. The infrared spectrum, water absorption ratio, solid content and hydrolysis degree of the polymer microspheres were determined. On the basis of, in the monomer added soluble starch modification of polymer microspheres, through the orthogonal experiment of four factors and three levels on the polymer monomer conversion rate, solid content, degree of hydrolysis, plugging performance were discussed, with better comprehensive properties of starch polyacrylamide core-shell microspheres, determined the optimal conditions of polymerization of polyacrylamide starch modified. At the same time, the PAM polymer microspheres were prepared by inverse emulsion polymerization with styrene and acrylamide as the main body and the oil and water phase as the reaction. On the basis of the second chapter by single factor method of kinds and amounts of emulsifiers, emulsifier, oil phase trigger agent and adding way, oil phase monomer adding time and amount of, and through the five factor and four level orthogonal experimental method of polymer monomer conversion rate, solid content, degree of hydrolysis, plugging performance are discussed, with good comprehensive properties that swelling, salt, resistance to temperature and better polystyrene - polyacrylamide microspheres with core / shell structure, determined the optimum technological conditions of the polymerization. The above research lays the foundation for the industrial production and application.