A high-temperature-resistant, low-friction, aggravated clean fracturing fluid and its preparation method

Abstract

The invention discloses a high-temperature-resistance low-friction weighted clean fracturing fluid which is suitable for high-temperature and high-pressure reservoir reconstruction at 170 DEG C and a preparation method thereof.The fracturing fluid is prepared from, by weight, 0.2%-0.8% of high-temperature-resistance thickening agent, 0.1%-0.8% of system synergist, 0.1%-0.3% of high temperature stabilizer, 0%-42% of weighting agent and the balance fresh water.The high-temperature-resistance low-friction weighted clean fracturing fluid has the following functions and advantages that the weighting agent can be adopted for weighting, and the density is adjustable between 0 and 1.32 g / cm<3>; good temperature-resistance and anti-shearing properties are achieved, and the requirement of high-temperature deep well fracturing construction at 170 DEG C can be met by adjusting a formula; a good resistance reduction property is achieved, pipeline friction resistance can be effectively reduced, and the resistance reduction rate can reach 70%; the fracturing fluid is a fluid with a reversible structure, and the structure damage after high shearing is small; the residue content of the fracturing fluid is decreased to below 10 mg / L, damage to a reservoir and supporting cracks is reduced, the fracturing effect is improved, and the reservoir productivity is increased.

Description

technical field [0001] The invention relates to the technical field of increasing production of oil and gas reservoirs, in particular to a high-temperature-resistant, low-friction aggravated clean fracturing fluid that can be applied to high-temperature deep well reservoir reconstruction. Background technique [0002] Fracturing fluid is one of the keys to fracturing low-permeability reservoirs. With the continuous development of fracturing to deep wells and ultra-deep wells, the characteristics of high temperature, high pressure, and abnormal fracture pressure have also become challenges that fracturing fluid technology must face. Therefore, new requirements are put forward for fracturing fluid technology. [0003] For high-temperature, deep-well and high-pressure reservoirs, due to the tight development of oil and gas reservoirs, strong structural stress, high formation pore pressure and serious reservoir damage, high formation fracture pressure and fracture extension pres...

AI Technical Summary

Problems solved by technology

But so far, the commonly used weighted fracturing fluids also have many problems. First, although ordinary guar gum weighted fracturing fluids have good temperature resistance, they have high residue content, difficult control of cross-linking time, and high pipeline friction , not anti-shear and other shortcomings can not be ignored; secondly, the VES viscoelastic surfactant fracturing fluid, which is considered to be clean and residue-free, can significantly reduce the damage, but its temperature resistance is poor, the use temperature is limited, and it is not compatible with the weighting agent. The compatibility is poor, and it cannot meet the fracturing requirements of high temperature, high pressure and deep well reservoirs

[0005] At present, relevant enterprises at home and abroad have also conducted some research on fracturing fluid and achieved certain results, such as "Clean Fracturing Fluid and Its Application" with application number 200910013666.X, "Clean Fracturing Fluid" with application number 201210077974.0, application No. 201310189229.X "Heavy Fracturing Fluid", etc., but these fracturing fluids still have certain problems in realizing the functions of reducing friction, increasing density, and cleaning recovery, especially the inability to decompose and recover without residue. There is still some pollution

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