| The plugging agents of exploiting fractured-vuggy reservoirs should meet the following technical requirements,which are the size of plugging agents from 0.5 to 1 mm,the oil solubility of the temporary plugging agents over 50 weight percent,plugging agents with a certain delay bonding time,and plugging agents with strong self-adhesive capability at high temperature,etc.In view of the above challenges,four new self-adhesive plugging agents had been prepared in this thesis.The temporary plugging feasibility for the four plugging agent materials was discussed.1.Preparation and properties of self-adhesive polyacrylate resin were studied in the first part.Polyacrylate resins were synthesized by suspension polymerization,based on the mixture of butyl methacrylate(BMA),octadecyl methacrylate(SMA)and styrene(St)as monomer,dibenzoyl peroxide(BPO)as initiator,N,N-methylenebisacrylamide(MBA)as crosslinking agent.The effect of the content for St and MBA on the oil solubility,self-adhesion and thermal stability of the resin were studied respectively,the comparison on above properties of traditional resins such as thermoplastic polyethylene(TPE),thermoplastic styrene-butadiene resin(SBS)and ethylene propylene rubber(EPDM)had been made also.The results showed that the oil-solubility and self-viscosity of the self-made polyacrylate resin were better than those of TPE,SBS and EPDM,and showed the features of strong self-adhesion and high oil-solubility at high temperature.2.Preparation and properties of polyacrylate resin coated rubber blocking agent were explored in the second part.Resin-coated rubber plugging agent particles were prepared by coating polyacrylate resin on nitrile rubber(NBR)particles.The oil-solubility,self-adhesion and thermal stability of the resin-coated plugging agent were studied,and compared with resin plugging agent and NBR plugging agent.The coated rubber plugging agent showed strong adhesive capability and higher performance.3.Preparation and properties of self-adhesive compound initiated rubber plugging agents were carried out in the third part.Using NBR,natural rubber(NR)and EPDM as matrix,BPO,sulfur(S)and dicumyl peroxide(DCP)as mixed vulcanizing agents,three kinds of composite rubber plugging agents were prepared by physical blending in miller.The effect of vulcanization temperature on the properties of rubber plugging agents were studied.The oil solubility,self-viscosity and thermal stability of the three rubber plugging agents were compared.The results showed EPDM plugging agents vulcanized at 80 ? or 120 ? had high oil solubility,a certain delay bonding time at room temperature,and good bonding property at 130 ?.EPDM plugging agent is suitable for application in fractured-vuggy reservoirs.4.Preparation and properties of self-adhesive agents of polyacrylate resin composite rubber were discussed in the fourth part.The synthetic resin was used as modifier to modify the rubber plugging agents by physical blending.The effect of vulcanizing temperature on the properties of the resin modified rubber plugging agents were studied,and the effect of resin on the properties of the rubber plugging agents were analyzed.The results showed that the lipophilicity and self-adhesion of NBR and EPDM plugging agents were improved,the plugging agents was optimized,and EPDM plugging agents vulcanized at 80 ? or 120 ? are more suitable for plugging Tahe oilfield after resin modification. |
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