Design And Characteristic Simulation Of Pipeline Sealing Hydrogel

Long-distance oil and gas pipeline leakage and explosion and other major safety incidents are caused by high load and harsh use environment.Pipeline plugging technology is the core technology to solve the problem of pipeline replacement and maintenance.Traditional mechanical plugging technology has heavy equipment and complex process,which makes it difficult to quickly complete pipeline plugging under harsh working conditions.Based on the characteristics of high strength,biodegradability and controllability of synthesis of polymer materials,we propose to use polymer materials for pipeline plugging.However,the process of polymer polymerization is complex,which is affected by many uncertainties such as the types of monomers and reaction conditions.The experimental research process takes a long time and has poor controllability.MC molecular simulation software was used to study the polymerization process,and the simulation results were used to further guide the design of the experiment.the model of polymerization was established and the molecular dynamics simulation of the polymerization process was carried out.The results show that the simulation results of the length distribution,the number of chain molecules,the average length of chain segments and the degree of number-average polymerization are in good agreement with the classical Flory polycondensation theory.When the reactivity of the monomers is similar,the simulation results are in good agreement with the theoretical results by changing the feed ratio of the monomers.It shows that the simulation process model accords with the characteristics of the second-order reaction theory,and further verifies the correctness of the polymerization model.Aiming at the selection of experimental monomers,the ratio of feeding materials and the design of temperature experimental parameters.The effects of different monomer activities on thelength of molecular chains in the process of polymerization were simulated by using the model of polymerization.The results show that when the activity of the added monomer is equal to or higher than that of the basic monomer,the length of the molecular chain increases,but when the activity is too high,it is difficult to form a polymer network structure.When the activity of the copolymer was the same,the crystallization of the copolymer was simulated at different temperatures.The results show that when the feed ratio of the two monomers is quite different,we find that the micro-monomers are mosaic in the main chain in the form of free dispersion,so the micro-copolymerization has little effect on the main chain sequence.The morphology of micelles formed by copolymers in solvents is influenced by the content of copolymer units and the sequence structure.Aiming at the complex rheological problem of hydrogel in pipeline,we compiled the flow simulation process of incompressible viscoelastic fluid in pipeline by C language.Based on ALE free surface tracing technique and iterative step-by-step algorithm,we simulated the flow of viscoelastic fluid in "Z" pipe.The results show that no deformed meshes appear in the simulation.In order to obtain high strength polymer hydrogels.Based on the simulation results of monomer activity,feed ratio and temperature,we chose acrylamide as the basic monomer.By changing the feed ratio of acrylic acid and acrylamide and the reaction temperature,we designed a single factor experiment of monomer feed ratio AM:AA=5:1,the reaction temperature was 25℃,50℃.The results show that the hydrogel has a higher pressure-bearing capacity at50℃,and the pressure-bearing value is 45 N.Furthermore,a single factor of 5:1,3:1 and 1:1 for acrylamide and acrylic acid was designed when the polymerization temperature was 50℃.The results show that the hydrogel with pressure-bearing property of 55 N can be obtained at the reaction temperature of50 ℃ and the feed ratio of 1:1.The optimal group is selected to simulate the pressure-bearing plugging of pipelines.The results show that the optimal group of hydrogels completes the pipeline plugging with 190 mm inner diameter and 1000 mm length.The pressure value is 0.2Mpa,the plugging time is 12 hours.