A slippery water system with low adsorption damage

Abstract

The invention discloses a low-absorption-damage slick water system. The low-absorption-damage slick water system is prepared from the following components in percent by mass: 0.05-0.1% of resistance reducing agent, 0.1-0.5% of discharging aiding agent, 0.1-0.3% of desorbing agent and the balance of water, wherein the resistance reducing agent is linear polyacrylamide commonly-used in an oil field,and the weight-average molecular weight is 5-8 million; the discharging aiding agent is anion fluorocarbon surfactant; the desorbing agent is prepared from the following components in percent by mass: 8-15% of urea, 1-2% of SiO2 nanoparticle, 3-5% of cetyl sodium sulfate, 20-30% of ethylene glycol and the balance of water. The low-absorption-damage slick water system disclosed by the invention has the beneficial effects that the absorbing amount of the polyacrylamide in the slick water on the surface of shale rock can be obviously reduced, the yield-increasing effect after fracturing is improved; after the desorbing agent is added into the slick water system, the cost is increased by less than 10%, and the construction process is not changed, so that the market application prospect is wide.

Description

technical field

[0001] The invention relates to a slick water system used for fracturing stimulation in the shale gas development process, in particular to a slick water system with low adsorption damage. Background technique

[0002] Shale gas, as an efficient, clean and unconventional natural gas resource with great potential, has become a key energy source for development in my country. my country has a total of 54 shale gas exploration rights blocks, with an area of ​​about 17×10 4 km 2 . Shale gas reservoirs must be fractured to generate industrial gas flow. Shale fracturing needs to break the rock by injecting high-volume fluid, forming a large number of network fractures and carrying proppant with small particle size into the fractures. Slippery water with good drag-reducing performance is the first choice for large-volume construction . Slick water fracturing not only reduces the fracturing cost by 65% ​​compared with large-scale hydraulic fracturing in the same...

Examples

Embodiment 1

[0017] Add 40g of water to the small mixing tank, then add 8g of urea and 1g of SiO 2 Add 20g of ethylene glycol to the nanoparticles, stir evenly, then add 3g of sodium cetyl sulfate, add 28g of water and stir for 30min to obtain the desorbent.

[0018] Preparation of slippery water system with low adsorption damage: put 99.52kg of water into the mixing tank, add 0.08kg of linear polyacrylamide, 0.2kg of desorbent, stir evenly, then add 0.2kg of perfluorotetradecyl sodium sulfate, and stir for 20min .

Embodiment 2

[0020] Add 40g of water to the small mixing tank, then add 15g of urea and 2g of SiO 2 Add 30g of ethylene glycol to the nanoparticles, stir evenly, then add 5g of sodium cetyl sulfate, add 8g of water and stir for 30min to obtain the desorbent.

[0021] Preparation of slippery water system with low adsorption damage: put 99.55kg of water into the mixing tank, add 0.05kg of linear polyacrylamide, 0.1kg of desorbent, stir well, then add 0.3kg of perfluorotetradecyl sodium sulfate, and stir for 20min .

Embodiment 3

[0023] Add 40g of water to the small mixing tank, then add 10g of urea and 1.5g of SiO 2 Add 25g of ethylene glycol to the nanoparticles, stir evenly, then add 4g of sodium cetyl sulfate, add 8g of water and stir for 30min to obtain the desorbent.

[0024] Preparation of slippery water system with low adsorption damage: put 99.3kg of water into the mixing tank, add 0.1kg of linear polyacrylamide, 0.3kg of desorbent, stir evenly, then add 0.3kg of perfluorotetradecyl sodium sulfate, and stir for 20 minutes .

[0025] Viscosity, resistance reduction rate and injury rate of comparative example and embodiment are tested in laboratory. The damage rate test uses shale outcrop, and the damage performance is tested based on the standard "Water-based Fracturing Fluid Performance Evaluation Method", as shown in the table below. It can be seen from the table that the viscosity and drag-reducing performance have no effect, but under the same formula, the damage rate of slick water to th...

technical field

[0001] The invention relates to a slick water system used for fracturing stimulation in the shale gas development process, in particular to a slick water system with low adsorption damage. Background technique

[0002] Shale gas, as an efficient, clean and unconventional natural gas resource with great potential, has become a key energy source for development in my country. my country has a total of 54 shale gas exploration rights blocks, with an area of ​​about 17×10 4 km 2 . Shale gas reservoirs must be fractured to generate industrial gas flow. Shale fracturing needs to break the rock by injecting high-volume fluid, forming a large number of network fractures and carrying proppant with small particle size into the fractures. Slippery water with good drag-reducing performance is the first choice for large-volume construction . Slick water fracturing not only reduces the fracturing cost by 65% ​​compared with large-scale hydraulic fracturing in the same...

Examples

Embodiment 1

[0017] Add 40g of water to the small mixing tank, then add 8g of urea and 1g of SiO 2 Add 20g of ethylene glycol to the nanoparticles, stir evenly, then add 3g of sodium cetyl sulfate, add 28g of water and stir for 30min to obtain the desorbent.

[0018] Preparation of slippery water system with low adsorption damage: put 99.52kg of water into the mixing tank, add 0.08kg of linear polyacrylamide, 0.2kg of desorbent, stir evenly, then add 0.2kg of perfluorotetradecyl sodium sulfate, and stir for 20min .

Embodiment 2

[0020] Add 40g of water to the small mixing tank, then add 15g of urea and 2g of SiO 2 Add 30g of ethylene glycol to the nanoparticles, stir evenly, then add 5g of sodium cetyl sulfate, add 8g of water and stir for 30min to obtain the desorbent.

[0021] Preparation of slippery water system with low adsorption damage: put 99.55kg of water into the mixing tank, add 0.05kg of linear polyacrylamide, 0.1kg of desorbent, stir well, then add 0.3kg of perfluorotetradecyl sodium sulfate, and stir for 20min .

Embodiment 3

[0023] Add 40g of water to the small mixing tank, then add 10g of urea and 1.5g of SiO 2 Add 25g of ethylene glycol to the nanoparticles, stir evenly, then add 4g of sodium cetyl sulfate, add 8g of water and stir for 30min to obtain the desorbent.

[0024] Preparation of slippery water system with low adsorption damage: put 99.3kg of water into the mixing tank, add 0.1kg of linear polyacrylamide, 0.3kg of desorbent, stir evenly, then add 0.3kg of perfluorotetradecyl sodium sulfate, and stir for 20 minutes .

[0025] Viscosity, resistance reduction rate and injury rate of comparative example and embodiment are tested in laboratory. The damage rate test uses shale outcrop, and the damage performance is tested based on the standard "Water-based Fracturing Fluid Performance Evaluation Method", as shown in the table below. It can be seen from the table that the viscosity and drag-reducing performance have no effect, but under the same formula, the damage rate of slick water to th...