Gas well water blocking damage treating agent

Abstract

The invention belongs to a fracturing fluid additive, and in particular relates to a gas-well water-lock damage treating agent. The agent is characterized in that the treating agent is formed by the following components in weight percentage: 15.0 to 20.0 percent of 2, 3-epoxypropyltrimethylammonium chloride as a main agent, 4.0 to 7.0 percent of nonionic surfactant, 0.5 to 0.8 percent of fluorocarbon surfactant, 5.0 to 8.0 percent of cationic surfactant, and the balance being distilled water. The nonionic surfactant is octylphenol polyoxyethylene ether or dodecyl phenol polyoxyethylene ether.The fluorocarbon surfactant is SR18Y fluorocarbon surfactant which is a product of Shaanxi Senrui Science and Technology Co.,Ltd. The cationic surfactant is di-8 / 10 alkyl dimethyl ammoniumbromide or tetradecyl dimethyl benzyl ammonium. The gas-well water-lock damage treating agent has the advantages of reducing gas-well water-lock damage, lowering starting pressure, improving the gas phase permeability of rock cores and protecting reservoirs.

Description

technical field [0001] The invention belongs to fracturing fluid additives, in particular to a gas well water lock damage treatment agent for reducing gas well water lock damage, reducing start-up pressure, improving rock core gas phase permeability and protecting reservoirs. Background technique [0002] Water lock damage seriously affects the development effect of gas reservoirs, and has become one of the main damages of low-permeability tight gas reservoirs. payback period, etc. [0003] The degree of water lock damage is related to the size and distribution of reservoir pore throats, reservoir permeability, pressure and time of interaction between external fluid and rock, original water saturation, formation pressure, contact angle and fluid viscosity and other factors. For low-permeability reservoirs, as the permeability decreases, although the amount of foreign fluid entering the reservoir decreases under the same pressure difference, the capillary radius decreases, t...

AI Technical Summary

Problems solved by technology

For low-permeability reservoirs, as the permeability decreases, although the amount of foreign fluid entering the reservoir decreases under the same pressure difference, the capillary radius decreases, the self-absorption increases, and this part of self-absorption water is less likely to flow back come out

If the low pressure of the reservoir is added, the degree of water lock damage will increase significantly, but when the permeability decreases to a certain level, the degree of water lock damage will decrease again when the external fluid cannot enter the formation by self-priming

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