Study On The Rapid Preparation Of Gel System And Its Application

To enhance the utilization efficiency of offshore platforms and to solve problems including the increased heterogeneity and water content in Chengdao offshore oil fields in Shengli and inefficient passing of particle profile control agents due to the seabed sand filter.A gel system with good shear resistance can fast configuration was studied.The author conducted a laboratory comparison between emulsion polymer and dry powder polymer products.The molecular weight,effective content were determined.With polymer's quick dissolving as the prerequisite and its stable gelling property as the condition.The bottle test was used to determine the gelling properties.Finally,a emulsion polymer which can rapidly dissolve and has stable gel forming properties is selected.The author combined it with a lab-made organic chrome cross-linking agent and obtained a profile control system supporting quick configuration.With lab tests,the author further studied the effect of concentration of each component therein and stratigraphic environmental factors on its gelling performance.The breakthrough vacuum strength method was used to determine the gel strength.Determination of gelation time by bottle test.On the basis of the results of a series of indoor experiments,the profile control system have been further analyzed and optimized.The author has evaluated the thermal stability and shear stability of the selected formula and looked into the dynamic and static gelling process of the system.After that,the author designed an simulated offshore online injection experiment and a lab physical model profile experiment,on which basis a pilot test was run at well CACB11NB-7 in Chengdao offshore oil fields and the construction results tracked and evaluated.The result show the emulsion can be completely dissolved in about 25 min under the condition of mine.The formula was obtaining through laboratory test and its applied range:1.6%-1.8% emulsion polyacrylamide,0.3%-0.5% organic chrome cross-linking agent,gelation time for 9-20 h,gel strength of 0.06-0.07 MPa,system gelation temperature at60-80?,the highest salinity must be less than 40000 mg/L,and the p H tolerance ranges from6 to 8.The results show that the system has stable gelling property,good thermal stability and good salt and acid and alkali resistance under reservoir conditions.On-site monitoring indicated effective improvement of the injection profile after profile control;injection pressure at the wellhead increased by 4 MPa;daily yield of the corresponding oil well increased by 3.7 t and water content reduced by 1.2%.This shows that the research in this paper has achieved certain results in the field,and has a certain guiding value for the future work of improving oil recovery at sea.