A kind of foam well washing fluid and preparation method thereof

Abstract

The invention discloses a foam well washing fluid and a preparation method thereof. The well flushing fluid includes the following components in weight percent: 0.1% to 0.5% of bactericide, 0.01% to 0.05% of ion stabilizer, 0.1% to 0.3% of foaming agent, 0.1% to 0.3% of thickener, and 0.02% of crosslinking agent %~0.045%, and the balance is oilfield sewage. The foam well-washing fluid prepared by using oilfield sewage in the present invention has excellent foaming performance and foam-stabilizing performance, meets the requirements of on-site construction, not only alleviates the demand for clean water resources in oilfield well-washing operations, but also solves the problem of oilfield produced formation water treatment; At the same time, it has low density, strong sand-carrying performance, good filtration loss reduction effect, and high well washing efficiency, which can reduce formation damage to low-pressure oil and gas wells; has good economic and environmental benefits, and is suitable for popularization in oil field low-pressure oil and gas well washing operations. application.

Description

Technical field: [0001] The invention relates to a foam well flushing fluid, which is mainly used for low-pressure oil and gas wells with serious leakage of well fluid during well flushing, so as to reduce pollution and damage to low-pressure oil and gas layers. Background technique: [0002] After the oil and gas field enters the middle and late stage of development, the formation deficit is serious due to sand production, resulting in a drop in formation pressure. After long-term exploitation of these low-pressure oil and gas wells, a lot of dirt such as sand and mud has accumulated in the wellbore, causing the oil and gas production layers to be clogged to varying degrees and reducing the production of oil and gas wells. In the past, clear water or sewage was generally used for well flushing operations. Because the formation pressure was lower than the hydrostatic column pressure, a large amount of well fluid leaked into the reservoir during the well flushing operation. ...

AI Technical Summary

Problems solved by technology

However, at present, in order to save water resources and liquid preparation costs, most of the foam well-flushing fluids are prepared on-site with high-salinity oilfield sewage, resulting in a significant decrease in the foaming volume and foam stability of the foam, which cannot meet the construction requirements of the foam well-flushing site

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