Easily-degradable alkali-free viscosity reducer for thick oil and preparation method thereof

Abstract

The invention relates to an easily-degradable alkali-free viscosity reducer for thick oil and a preparation method thereof. The viscosity reducer consists of propylene glycol block polyether, fatty alcohol ammonium sulfate, fatty alcohol, a penetrating agent and water; and in terms of the total mass of the viscosity reducer, the sum of mass percent of propylene glycol block polyether, fatty alcohol ammonium sulfate, fatty alcohol and the penetrating agent is 45 to 60 wt%. The invention also provides the preparation method for the viscosity reducer, and the method comprises the following steps: successively adding propylene glycol block polyether, fatty alcohol ammonium sulfate, fatty alcohol and the penetrating agent into water at a temperature of 50 to 80 DEG C under normal pressure, wherein a mass ratio of the four above-mentioned raw materials to water is 15: 15: 5: 10: 55 to 25: 25: 4: 6: 40; and carrying out continuous stirring for 60 to 90 min at a rotating speed of 60 to 120 r/min while adding the four raw materials so as to obtain the easily-degradable alkali-free viscosity reducer for thick oil. Surfactant used in the viscosity reducer is nonionic and anionic surfactant, the structure of benzene rings is not included in a molecule, and therefore, the characteristics of easy degradability, no toxicity, greenness and environment friendliness are obtained.

Description

technical field [0001] The invention relates to a heavy oil viscosity reducer, in particular to an easily degradable alkali-free heavy oil viscosity reducer, which belongs to the technical field of petroleum exploitation. Background technique [0002] At present, two methods of mixing thin oil and electric heating have been used in the wellbore lifting process of heavy oil and ultra-heavy oil, and the surface pipeline adopts high-temperature heat-tracing transportation technology. The lifting process of heavy oil mixed with thin oil has the problems of loss of price difference between thin oil and heavy oil and the reduction of thin oil that can be mixed. The problem of high consumption has greatly increased the production cost per ton of oil. [0003] The use of heavy oil viscosity reducer in heavy oil production, lifting, gathering and transportation is an effective chemical viscosity reduction method with low cost and low energy consumption. Its main mechanism is to make...

AI Technical Summary

Problems solved by technology

Currently the most widely used viscosity reducer, its main component is basically non-ionic alkylphenol ether surfactant (OP or NP type) or anionic surfactant alkylbenzene sulfonate or petroleum sulfonate (AS or PS), and this type of surfactant has a very stable benzene ring structure in its molecular structure, and its disadvantages are difficult to degrade, high toxicity, and easy to pollute the environment; Containing inorganic alkali components, the pH value of most viscosity reducers is slightly alkaline. Although thick oil viscosity reducers containing alkaline substances have good emulsification and viscosity reduction effects, the biggest disadvantage is that the formed oil-water emulsion is too stable. It is not conducive to the demulsification and dehydration of the combined station in the later stage, that is, this kind of viscosity reducer is not compatible with the demulsifier, and it is easy to cause fouling and corrosion of oil well strings and oil pipelines.

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