Biological enzyme fracturing outlet liquid recovery oil displacement and plugging relief technology

Abstract

The invention relates to a biological enzyme fracturing outlet liquid recovery oil displacement and a plugging relief technology comprising the following steps: (1) after biological enzyme fracturing outlet liquid is subjected to gel breaking, a flocculating agent or an adhesive mud removing agent or a bactericide is added into the biological enzyme fracturing outlet liquid to accumulate suspended matters and sterilize the fracturing outlet liquid; (2) the sterilized biological enzyme fracturing outlet liquid is initially filtered and recovered by a well cleanout truck with a filtering function or a precise filter; (3) the recovered biological enzyme fracturing outlet liquid is finely filtered again from 2 microns to 150 microns by the precise filter according to requirements; and (4) after the recovered biological enzyme fracturing outlet liquid is finely filtered, a chemical agent is added into or compositely prepared with the biological enzyme fracturing outlet liquid. The recovery rate of the biological enzyme fracturing outlet liquid processed by the technology can reach more than 70 percent, the invention thoroughly solves the problem of the environment pollution of the biological enzyme fracturing outlet liquid, enhances the recovery ratio of crude oil by more than 6-18 percent, prevents incrustations being accumulated again and reduces the oil-water interfacial tension.

Description

technical field [0001] The invention relates to a waste liquid chemical recovery process, in particular to a bio-enzyme fracturing flowback liquid recovery oil displacement and block removal process. Background technique [0002] With the continuous development of hydraulic fracturing, various sand-carrying fluids have emerged. In water-based, emulsified and foam fracturing operations, the most used fracturing fluid is water-based gel fracturing fluid, in which thickeners are some high molecular polymers, such as boron cross-linked guar gum, hydroxypropyl fracturing fluid, etc. Base cellulose, polyacrylamide, etc. These polymers can basically meet the requirements for liquids in current on-site construction. However, due to the high molecular weight of the polymer and the large amount of water-insoluble matter, it is cross-linked with a cross-linking agent to form a supermacromolecule. The completely broken supermacromolecules stay in the cracks, which reduces the permeab...

AI Technical Summary

Problems solved by technology

However, due to the high molecular weight of the polymer and the large amount of water-insoluble matter, it is cross-linked with a cross-linking agent to form a supermacromolecule. The completely broken supermacromolecules stay in the cracks, which reduces the permeability of the formation and the construction effect is not good

In addition, in the whole fracturing process, there are many kinds of fracturing fluid admixtures, thickeners have slow dispersion and swelling speed, etc., which seriously affect the quality of fracturing fluid.

People have recognized this hazard, and made great improvements in the gel breaking system and additives, but there is still little effect on reducing residues and improving fracturing quality