Prepn and application of alkyl aryl sulfonate

Abstract

The preparation process of alkyl aryl sulfonate includes the following main steps: adding C8-C26 straight chain alkylbenzene in 0-50 wt% to heavy alkylbenzene of average molecular weight of 310-370; sulfonation reaction of mixed alkylbenzene and fuming sulfuric acid in the weight ratio of 1 to 0.3-3 inside a sulfonation reactor, with the adding speed of fuming sulfuric acid being controlled to result in reaction temperature of 40-55 deg.c adding water in the amount of 5-25 % of total material weight through stirring at 30-80 deg.c; for 0.2-3 hr and stagnation to balance for 0.5-5 hr; and neutralizing the ractant mixture to pH 8-9 with 10-40% concentration NaOH solution. The alkyl aryl sulfonate is applied in tertiary oil extraction to compound oil displacing agent and may form stable superlow interface tension area in relatively low and wide alkali concentration range and relatively side surfactant concentration range.

Description

technical field [0001] The invention relates to a surfactant for oil field flooding, in particular to a preparation method of alkyl aryl sulfonate. [0002] The present invention also relates to the application of the above-mentioned alkylaryl sulfonate in tertiary oil recovery. Background technique [0003] Petroleum is an important resource of energy and chemical raw materials in my country. Since oil is naturally occurring and non-renewable, the quality of oil development is critical. [0004] At present, oil field development still adopts primary oil recovery and secondary oil recovery of water flooding. Applying the above oil recovery method, only 20-40% of the original reserves of the formation can be recovered, and 60% or more of the crude oil remains underground. In order to extract the residual oil in the ground, people have studied many tertiary oil recovery methods, among which the fastest developing speed and the best application prospect should be the surfact...

AI Technical Summary

Problems solved by technology

Therefore, the composition of petroleum sulfonate produced from crude oil distillate oil is complex, the equivalent distribution is wide, and the performance of sulfonate is not easy to control

In particular, the molecular structure of some components of sulfonate is similar to the molecular structure of certain components in the displaced oil, so it can be used for product application and related technical processing, such as mine scheme design, numerical simulation research, oil displacement process The determination and control of certain parameters (interfacial tension, adsorption capacity of different chemical agents, etc.), and the admission of relevant materials... have brought a lot of trouble

In addition, the content of sulfonated substances in crude oil fractions is low, so no matter what process is used to produce petroleum sulfonates, solvent extraction technology must be used to reduce the content of unsulfonated oil in the product and increase the content of effective active substances. Bring troubles on the process and increase the cost and power consumption to the production

[0008] 2. A large number of field tests and laboratory studies have shown that whether it is petroleum sulfonate or synthetic alkylaryl sulfonate, the process of forming an ultra-low interfacial tension between the oil displacement agent formulated with it and the displaced oil ( time) is long, so that when the residual oil in the formation contacts with the displacement agent, the ultra-low interfacial tension (10 -3 mN / m order of magnitude), is taken away by the oil-displacing agent and becomes the mobile phase, affecting the oil-displacement efficiency of the oil-displacing agent

[0009] 3. The surfactant-alkali binary system and surfactant-alkali-polymer ternary system formulated with the above-mentioned sulfonate can form ultra-low interfacial tension (10 -3 mN / m order of magnitude), but then the interfacial tension rises rapidly, so that the residual oil that becomes the mobile phase is trapped again and remains underground, which affects the oil displacement efficiency of the oil displacement agent.

[0011] Second, the process conditions

[0012] 1. At present, the production of petroleum sulfonates and many alkylaryl sulfonates (especially heavy alkylbenzene sulfonates) mostly adopts continuous membrane sulfonation. Due to the high viscosity of the raw material oil, it is often necessary to add some Organic solvents, some or all of these solvents will remain in the product, complicating the composition of the product and increasing the production cost of the product

[0013] 2. Membrane continuous sulfonation, with gas SO 3 is the sulfonating agent, SO 3 It reacts violently with alkylaromatics, and the depth of sulfonation is difficult to control

[0014] 3. Production of petroleum sulfonate and heavy alkylbenzene sulfonate by membrane sulfonation is easy to coke

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