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...

Examples

Embodiment 1

[0025] Example 1: According to the weight percentage, add 75.5% distilled water to the reaction kettle, then add 15% main agent 2,3-epoxypropyltrimethylammonium chloride, stir for 15min; heat up to 35°C, then add 4.0% Nonionic surfactant octylphenol polyoxyethylene ether, add 0.5% SR18Y fluorocarbon surfactant produced by Shaanxi Senrui Technology Co., Ltd., stir for 10 minutes; finally add 5.0% cationic surfactant double 8 / 10 alkyl dimethyl ammonium bromide, and stirred for 10 minutes to obtain a gas well water lock treatment agent.

Embodiment 2

[0026] Example 2: By weight percentage, add 64.2% distilled water to the reactor, add 20% main agent 2,3-epoxypropyltrimethylammonium chloride, stir for 20min; heat up to 40°C, then add 7.0% non- Ionic surfactant dodecylphenol polyoxyethylene ether, add 0.8% SR18Y fluorocarbon surfactant produced by Shaanxi Senrui Technology Co., Ltd., stir for 15 minutes; then add 8.0% cationic surfactant double 8 / 10 alkyl di Methyl ammonium bromide, stirred for 15 minutes to obtain a gas well water lock treatment agent.

Embodiment 3

[0027] Example 3: According to the weight percentage, add 70% distilled water to the reaction kettle, add 18% main agent 2,3-epoxypropyltrimethylammonium chloride, stir for 20min; heat up to 40°C, add 5.4% non-ionic Surfactant octylphenol polyoxyethylene ether, add 0.6% SR18Y fluorocarbon surfactant produced by Shaanxi Senrui Technology Co., Ltd., stir for 10 minutes; add 6.0% cationic surfactant tetradecyldimethylbenzyl ammonium chloride , and stirred for 15 minutes to obtain a gas well water lock treatment agent.

[0028] In the same block test, the conventional water-based fracturing fluid system was used for fracturing reconstruction in the early stage, the flowback period was long, and the single-layer unobstructed flow rate was 0-2000 cubic meters per day, which could not reach the industrial air flow. After the field test of the lock damage treatment agent, the flowback time was shortened by 62 hours, and the unimpeded flow rate of a single layer was 5,000 m3 / day, and t...

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...

Examples

Embodiment 1

[0025] Example 1: According to the weight percentage, add 75.5% distilled water to the reaction kettle, then add 15% main agent 2,3-epoxypropyltrimethylammonium chloride, stir for 15min; heat up to 35°C, then add 4.0% Nonionic surfactant octylphenol polyoxyethylene ether, add 0.5% SR18Y fluorocarbon surfactant produced by Shaanxi Senrui Technology Co., Ltd., stir for 10 minutes; finally add 5.0% cationic surfactant double 8 / 10 alkyl dimethyl ammonium bromide, and stirred for 10 minutes to obtain a gas well water lock treatment agent.

Embodiment 2

[0026] Example 2: By weight percentage, add 64.2% distilled water to the reactor, add 20% main agent 2,3-epoxypropyltrimethylammonium chloride, stir for 20min; heat up to 40°C, then add 7.0% non- Ionic surfactant dodecylphenol polyoxyethylene ether, add 0.8% SR18Y fluorocarbon surfactant produced by Shaanxi Senrui Technology Co., Ltd., stir for 15 minutes; then add 8.0% cationic surfactant double 8 / 10 alkyl di Methyl ammonium bromide, stirred for 15 minutes to obtain a gas well water lock treatment agent.

Embodiment 3

[0027] Example 3: According to the weight percentage, add 70% distilled water to the reaction kettle, add 18% main agent 2,3-epoxypropyltrimethylammonium chloride, stir for 20min; heat up to 40°C, add 5.4% non-ionic Surfactant octylphenol polyoxyethylene ether, add 0.6% SR18Y fluorocarbon surfactant produced by Shaanxi Senrui Technology Co., Ltd., stir for 10 minutes; add 6.0% cationic surfactant tetradecyldimethylbenzyl ammonium chloride , and stirred for 15 minutes to obtain a gas well water lock treatment agent.

[0028] In the same block test, the conventional water-based fracturing fluid system was used for fracturing reconstruction in the early stage, the flowback period was long, and the single-layer unobstructed flow rate was 0-2000 cubic meters per day, which could not reach the industrial air flow. After the field test of the lock damage treatment agent, the flowback time was shortened by 62 hours, and the unimpeded flow rate of a single layer was 5,000 m3 / day, and t...

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