Composite catalytic viscosity reducer for steam injection to thickened oil and preparation method and use thereof

Abstract

The invention relates to a composite catalytic viscosity reducer for thick oil steam injection production, as well as a preparation method and application thereof. The viscosity reducer is formed by combining three slugs, wherein a slug I comprises the following components in weight percentage content: 1 to 2 percent of cumene hydroperoxide, 1 to 3 percent of manganese oleate, 0.2 to 0.5 percent of sodium dihydrogen phosphate, 0.1 to 0.5 percent of alkaline matter and the balance being water; a slug II comprises the following components in weight percentage content: 0.05 to 0.1 percent of hydrothermal cracking catalysts, 0.05 to 0.2 percent of alkaline matter and the balance being water; and a slug III comprises the following components in weight percentage content: 0.1 to 0.5 percent of surfactant, 0.1 to 0.3 percent of alkaline matter and the balance being water. The composite viscosity reducer formed by combining three viscosity reducers has the advantages of good viscosity reducing effect, as well as wider adaptive range and better effects during field application through combination. Experiments prove that the composite viscosity reducer can reduce the viscosity of crude oil from 309,028 mPa.s to 55 mPa.s within 24 hours at a temperature between 100 and 200 DEG C, and reaches the viscosity reducing rate of over 99.9 percent.

Description

technical field [0001] The invention relates to a combined catalytic viscosity reducer for heavy oil steam injection exploitation, and also relates to a preparation method of the combined catalytic viscosity reducer for heavy oil steam injection exploitation, which belongs to the field of petroleum exploitation chemistry. 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 pe...

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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; in addition, catalytic viscosity reduction is generally applied to ultra-heavy oil, and ultra-heavy oil has large molecules and high viscosity. Under steam heating conditions, its fluidity and dispersion are relatively poor. When the injected catalyst enters the formation, due to the uneven dispersion of the ultra-heavy oil, it is difficult for the catalyst to fully mix with the crude oil, resulting in the inability of the catalyst to play an effective role, which also leads to The range of viscosity reduction is small, and the viscosity of crude oil recovers quickly