Self-cleaning or self-degrading temporary plugging agent and preparation method thereof

Abstract

The invention discloses a self-cleaning or self-degrading temporary plugging agent and a preparation method thereof. The self-cleaning or self-degrading temporary plugging agent is prepared from the following raw materials by weight: 40%-50% of polylactic acid, 25%-35% of a biodegradation agent, 2%-4% of glycerol, 4%-6% of polycaprolactone, 5%-7% of a thickening agent, 1%-3% of an alkaline solution and 0.1%-0.5% of a cross-linking agent, with the balance being water. According to the self-cleaning or self-degrading temporary plugging agent and the preparation method thereof, the temporary plugging agent can be degraded within 48 h, can absorb water to expand and crack at a formation temperature so as to realize loss of mechanical strength, and is finally degraded into water and carbon dioxide along with time increase; and the temporary plugging agent can be automatically degraded under a reservoir temperature condition, and can be automatically degraded after operation for high-water-content oil wells and water wells.

Description

Technical field

[0001] The invention belongs to the field of oilfield chemical technology, in particular a self-cleaning or self-deteriorating dismissal agent and a preparation method thereof. Background technique

[0002] At present, the use of extensive sewers can be classified from the interpolation, which can be divided into water-soluble temporary plug, oil-soluble suspected agent, acid-soluble tubing, and the oil-soluble temporary blocker can be degraded by crude oil due to the operation. It is widely used. However, with the development of oilfield, most of my country's land oil field has gradually increased, and the average oil well water content is more than 70%, and some oil wells have more than 90%, and the oil-soluble temporary agent degradation rate obviously decased. In addition, the pressure is unbalanced between the layers of injection wells. During the operation of repairing, matting, sand sand, the flow of the in-well fluid is serious, and there are many wells th...