Oxidative thinner for heavy oil exploitation via steam injection and preparation thereof

Abstract

The invention relates to an oxidization viscosity reducer for viscous oil recovery by steam injection and a preparation method thereof. The oxidization viscosity reducer comprises components by weight percentage: 0.5 to 10 percent of component A, 0.5 to 10 percent of component B, 0.1 to 8 percent of component C, 0.1 to 5 percent of component D, and the balance being water, wherein the component A is peroxide, the component B is transition metal salt of an organic acid, the component C is inorganic salt with the acidity shown in a hydrolysate, and the component D is an alkaline substance. The oxidization viscosity reducer can oxidize gelatine and asphaltine in viscous oil, reduce the viscosity of crude oil by changing a structure of the viscous oil through chain termination, oxidize to generate an acid substance at the same time, ensure that the viscous oil becomes a substance with the effect of a surfactant by adding the alkaline substance, and also play a role in viscosity reduction. The experiments show that the viscosity reduction rate can reach 99.9 percent when the viscosity reducer reacts with the crude oil for 24 hours at the temperature of 100 DEG C. The viscosity reducer has higher viscosity reduction rate, is applicable to the viscosity reduction of oil well stratums with high steam injection temperature, and also has good effect under relatively lower temperature conditions.

Description

technical field [0001] The invention relates to an oxidative viscosity reducer for steam injection of heavy oil, and also relates to a preparation method of the oxidative viscosity reducer for steam injection of heavy oil, which belongs to the chemical field of petroleum exploitation. Background technique [0002] The methods of steam injection huff and puff or steam flooding are commonly used in the production of heavy oil. Although the method of injecting heat medium can reduce the viscosity of crude oil, which is beneficial to the production of heavy oil, but after a short period of production after steam injection, the formation temperature will drop greatly, and the viscosity of heavy oil will decrease. increase again; therefore, in order to further improve the flowability of crude oil in the formation, it is often necessary to add active agents and other methods to reduce the viscosity of crude oil to prolong the thermal recovery period. However, for super heavy oil and...

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Problems solved by technology

[0005] Since the 1990s, domestic research on heavy oil underground upgrading based on hydrothermal cracking has been carried out. By adding transition metal salt catalysts, heavy oil viscosity reduction, gas generation comparison, heavy oil composition comparison, heavy oil component etc., studied the effect of the catalyst in detail and achieved certain results, but both hydrothermal hydrogenation and hydrogen supply by hydrogen donors require a temperature above 240°C, but the range of formation reaching this temperature under steam injection conditions is relatively small. Small catalyst radius and short production cycle are the most important factors restricting underground catalytic viscosity reduction, especially for heavy oil in shallow and thin layers such as Henan Oilfield, where the steam injection temperature is low and the formation temperature drops rapidly. The use of hydrothermal cracking or hydrogen supply modification requires a high reaction temperature, resulting in the catalyst not being able to effectively play a catalytic role and effectively improving the mining effect.