Hollow PVA fiber as well as preparation method and application thereof

Abstract

Hollow PVA fiber is prepared from PVA with the polymerization degree being 1,000-3,500 and the alcoholysis degree being 99.0-99.9(mol)% through spinning, wherein the section of the PVA fiber adopts a hollow structure, and the diameter of the hollow part is 0.1-100 mu m. The hollow PVA fiber is added to an oil and gas field fracturing fluid, so that the fracturing fluid has very good sand-carrying capacity, flowback of the fracturing fluid is facilitated, the usage amount of guar gum and other components which are difficult to dissolve completely and difficult to discharge from the bottom of a well can be reduced, and damage to environment is reduced; the hollow PVA fiber can improve the strength and the toughness of a cementing material and can also perform a leakage prevention function after being added to an oil and gas field cementing agent; the hollow PVA fiber has good filtration reduction function after being added to a temporary plugging agent used during fracturing of an oil and gas field and can form a shielding layer at to-be-temporarily plugged part, so that smooth diversion of the fracturing fluid can be realized. Components remaining in the environment can be decomposed into non-toxic hydrocarbon finally and cannot damage to the environment.

Description

technical field [0001] The invention relates to PVA fibers, in particular to a hollow PVA fiber and its preparation method and application. Background technique [0002] my country's low-permeability oil and gas resources are huge, accounting for more than 70% of the total proven reserves, and are the main potential areas for increasing reserves and production in the future. This type of oil and gas resources has the characteristics of three lows, that is, low proven rate, low natural production rate, and low recovery rate. The practical application shows that in the exploitation of such oil and gas fields, there is an urgent need for well-functioning cementing agents, fracturing temporary plugging agents, and oil and gas field fracturing fluids that can play a good role in carrying sand. At the same time, it is necessary to minimize the damage to the environment . [0003] In recent years, researchers at home and abroad have carried out a lot of research on fracturing, ce...

AI Technical Summary

Problems solved by technology

Although domestic and foreign colleagues have made a lot of efforts, so far, the existing fracturing technology still cannot achieve the purpose of reducing the damage of fracturing fluid to the reservoir and improving the sand-carrying performance. The existing fiber Due to its degradable properties and limitations in high temperature, acid and alkali resistance, it is not well used in oil and gas fields.

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