Research Of Alkyl Naphthalene Sulfonate Of Flooding Oil System

In this paper, Dioctyl methyl naphthalene was synthesized by using anhydrous aluminium trichloride as catalyst and 1-octene, methyl naphthalene as raw material. Dioctyl methyl naphthalene sulfonate was synthesized, chlorosulfonic acid as sulfonating agent.The emulsibility and adsorbability of dioctyl methyl naphthalene sulfonate were invesrigated.Alkylation of 1-octene and methyl naphthalene to synthesize Dioctyl methyl naphthalene. Influences of catalyst dosage, reaction temperature, reaction time and dropping time on conversion rate of octane, methyl naphthalene and yield of by-products were discussed, respectively. Optimal alkylation conditions were obtained as follows: 1:2 molar ratio of methylnaphthalene to 1-octene, 8% of catalyst dosage, the reaction temperature 40℃, reaction time 30 min, 1-octene dropping time 40 min, the conversion rate of octane and methyl naphthalene were above 95%, the yield of by-products was the lowest.Sulfonation of dioctyl methyl naphthalene to synthesize dioctyl methyl naphthalene sulfonate. Influences of the ratio of chlorosulfonic acid to oil, sulfonation temperature, sulfonation time on the balance interfacial tension were discussed. Optimal sulfonation conditions were obtained as follows: 1:2 molar ratio of chlorosulfonic acid to oil, the sulfonation temperature 50~70℃, the sulfonation time 50 min, interfacial tension of ternary system of dioctyl methyl naphthalene sulfonate can reach 10-3mN/m.Emulsibility of dioctyl methyl naphthalene sulfonate was invesrigated by using bleeding ratio as evaluation index. Influences of chemical type and concentration on the emulsion stability were discussed. Particle size distribution of droplets in the initial state emulsion was analyzed. <2μm particle of emulsion reached 60% and bleeding ratio of emulsion changed slowly, in ASP composed of 0.1% of dioctyl methyl naphthalene sulfonate, 0.6% of sodium carbonate and 1800mg/L of HPAM. In ternary systems, the lower of alkali concentration, the smaller of the average particle size, the more stability of emulsion.The mineral composition and pore structure character of the first and second reservoir were analyzed. The static adsorption capacity and dynamic retention of dioctyl methyl naphthalene sulfonate on a single mineral were investigated. The adsorbability of dioctyl methyl naphthalene sulfonate was evaluated. The results showed clay mineral adsorption was obviously greater than the matrix mineral adsorption, the adsorption isotherms of dioctyl methyl naphthalene sulfonate on the oil sand corresponded well with the Langmuir type; the core properties had great influence on the saturated adsorption.