Development of controllable cross-linking agent for methanol-based fracturing fluid

Abstract

The invention relates to a cross-linking agent for alcohol-based fracturing fluids, in particular to the development of a controllable cross-linking agent for methanol-based fracturing fluid, and the cross-linking time of the controllable cross-linking agent can be adjusted. For certain natural gas wells or oil wells with low formation pressure, low permeability and strong water-locking characteristic, the controllable cross-linking agent for methanol-based fracturing fluid can be used in the fracturing stimulation process. Inorganic zirconium or zirconate ester is adopted as a raw material, isopropanol or water or the mixture of isopropanol and water is adopted as solvent, suitable ligand is added, the materials react according to a certain material proportion under certain conditions for 4 hours, neutralizer is then added for neutralization, and finally, a moderate amount of diluent is added, so that the controllable cross-linking agent for methanol-based fracturing fluid is prepared. The cross-linking agent can be cross-linked with polymer with 60 to 100 percent of methanol content, the application range is wide, the dosage is little, and the controllable cross-linking agent cannot harm the environment. The biggest difference between the cross-linking agent disclosed by the invention and organic zirconium series cross-linking agents sold on the market is that mixed diluent formed by low-molecular weight sodium polyacrylate and low-molecular weight polyacrylic acid is adopted as the diluent of the controllable cross-linking agent.

Description

technical field [0001] The invention relates to an alcohol-based fracturing fluid cross-linking agent, in particular to the development of a methanol-based fracturing fluid controllable cross-linking agent with adjustable cross-linking time, which can be used as a cross-linking agent for some formations with low pressure, low permeability and strong Alcohol-based fracturing fluid cross-linking agent for oil and gas field stimulation with water-locking characteristics. Background technique [0002] At present, more than 90% of the fracturing fluids used in gas field fracturing are water-based fracturing fluids with water as the dispersion medium. It is a highly water-sensitive gas layer. Because the formation pressure coefficient is much lower than the pressure coefficient of water in the wellbore, it is easy to cause difficulty in liquid flowback; due to the water locking effect of the formation, it is easy to cause blockage of formation pores and make fracturing stimulation...

AI Technical Summary

Problems solved by technology

[0002] At present, more than 90% of the fracturing fluids used in gas field fracturing are water-based fracturing fluids with water as the dispersion medium. It is a highly water-sensitive gas layer. Since the formation pressure coefficient is much lower than the pressure coefficient of water in the wellbore, it is easy to cause difficulty in liquid flowback; due to the water locking effect of the formation, it is easy to cause blockage of the formation pores and make the fracturing treatment invalid.