Development Of Water-soluble Rubber Materials

In recent years,with the research and in-depth development of oil and gas exploration technology,the number of unconventional oil and gas reservoirs has been discovered more and more.Conventional vertical wells have been unable to meet the exploitation of unconventional oil and gas reservoirs.Horizontal wells are widely used in the exploitation of unconventional oil and gas reservoirs due to their large oil drainage area,high single well production,high penetration and high reserves.Splitting is a relatively core technology in horizontal wells,and the core component is a bridge plug.Conventional bridge plugs require more drilling or salvage after fracturing,and soluble bridge plugs have been developed for this purpose.The soluble bridge plug can be degraded into a crushed or slag in the solution and discharged out of the well through the oil well returning system.The matrix material of the soluble bridge plug includes a soluble metal and a soluble polymer.The water-dissolving rubber material is a kind of soluble polymer material,and has the characteristics of high sealing,strong pressure bearing and convenient processing.These features will solve the problems of insufficient pressure bearing and difficult processing of soluble bridge plugs,and promote the application of soluble bridge plugs in LPG mining.In this paper,the dissolution mechanism of water-soluble polymer is mainly used,and then several rubber matrix materials are selected.Finally,one or several hydrolyzing agents which can dissolve the rubber material quickly are found.After the mixing process,the hydrolyzing agent is mixed with the rubber.Post-vulcanization sample preparation.To achieve the purpose of the rubber material can be dissolved in water.Finally,after a lot of experiments and theoretical verification,the following points are obtained:(1)The dissolution mechanism of the water-dissolved rubber material is mainly ester hydrolysis;(2)ACM(polyacrylate rubber)can be dissolved in sodium hydroxide solution(80 to 120 ° C).Auxiliary sodium aluminate in ACM compounding formula is a better hydrolyzing agent;(3)Polyester MPU(polyester-based polyurethane rubber)can be dissolved in pure water(80 ~ 120 ° C),metal oxides,especially calcium oxide is the best hydrolyzing agent;(4)Polyether MPU(polyether compounded urethane rubber)can be dissolved in critical water(170 ° C and above),and its water resistance can be lowered by changing the formulation.The dissolution of these three rubbers in water is different,specifically polyether MPU>ACM>polyester MPU,because the amount of ester groups and the position in the molecule are different.The amount of ester group in the polyether MPU molecule is very small,so it is difficult to hydrolyze;the ester group in the ACM molecule is on the side chain,so it can be hydrolyzed and can only be dissolved in the sodium hydroxide solution;for the polyester MPU molecule,the main The chain contains many ester groups,so it is most easily hydrolyzed.Finally,it is concluded that the metal oxide can rapidly hydrolyze the ester in the rubber molecule and eventually dissolve in water or an aqueous solution.