Evaluation And Modification Of Resin Gel Plugging Materialsmaterial In Fracture Zone

The fracture zone formation is a complex formation commonly found in deep hole drilling.The stratigraphy and stratification of the stratum are developed.The rock or upper body is uneven in hardness and hardness.Faults and fractures often occur in the stratum.Due to its complex geological conditions and composition,frequent leakages occur during the drilling process.Methyl methacrylate(MMA)is a low-viscosity fluid before gelatinization.After gelatinization,the rubber block has high strength,and its own performance is stable and easy to trigger.So introducing MMA into the stratum,Initiating and indirectly controlling the gel formation time through the formation temperature and additives can block the formation loss channel and consolidate the formation to improve the bearing capacity of the formation.In this paper,by evaluating the influence of different factors on the polymerization reaction of MMA,the polymerization conditions were optimized,the preparation of MMA prepolymer was studied,the change rule of viscosity was explored,and the performance of prepolymer was systematically evaluated.Mainly carried out the following four aspects of work:1.The polymerization reaction conditions of polymethyl methacrylate are preferably: within the reaction temperature of 70-90?,the gel forming time gradually becomes shorter with the temperature increasing,and the compressive strength of the rubber block gradually decreases.Under the dosage of 50ppm-1000 ppm initiator,the gelling time can be adjusted from 10 min to 300 min.During the polymerization reaction initiated by dibenzoyl peroxide(BPO),the gelation time is shorter than AIBN under the same molar mass fraction,and the compactness of the rubber block is worse.2.The preferred conditions for the slow polymerization of polymethyl methacrylate: phenothiazine(PTZ)and tetramethylpiperidine oxynitride(TEMPO)within a 100 ppm dosage range have a significant delay effect on the MMA gel time,at the same temperature With the amount of initiator added,the gel forming time isproportional to the amount of inhibitor added;under the same molar mass,the inhibitory effect of tetramethylpiperidine nitrogen oxide is better than phenothiazine.3.The reaction conditions of the polymethyl methacrylate prepolymer are preferred: a redox initiation system composed of sodium bisulfite(SBS)and potassium peroxodisulfate,the viscosity-raising rate is slow during the preparation of the prepolymer,and the viscosity can be prepared to 2mpa · Prepolymer of s-2600mpa·s.4.The polymerization reaction conditions of polymethyl methacrylate prepolymer are preferred: as the reaction temperature increases,the gel forming time gradually decreases,and the compressive strength of the rubber block gradually decreases.The higher the amount of initiator added,the shorter the gel time,and the worse the compressive strength of the rubber block.The prepolymer is suitable for the reaction temperature of 75-85 ?,the amount of initiator should be less than 500 ppm.