An environmentally friendly anionic fracturing fluid and preparation method thereof

Abstract

The invention discloses environmental-friendly type negative ion fracturing fluid which is prepared by the following ingredients by weight percentage of 7% to 10% of anionic surfactant, 0.02% to 0.05% of methylene phosphonic acid, 4% to 7% of countra-ion salt, 0% to 0.4% of cosurfactant and the balance water. The pH value of the ion fracturing fluid is adjusted to 8 to 10 by a pH conditioning agent. The environmental-friendly type negative ion fracturing fluid is all prepared by micromolecule, good in water solubility, simple to prepare, capable of removing aging, short in preparation period, capable of achieving complete gel breaking with water or oil, quick in gel breaking, free of residue, free of affecting in-place permeability and capable of greatly improving fracturing reforestation effects. The used anionic surfactant avoids wetting transition and has no harm to stratums.

Description

technical field

[0001] The invention relates to the field of fracturing reconstruction of oil and gas wells, in particular to anion-cleaning fracturing fluid. Background technique

[0002] At present, all water-based fracturing fluids have residues without exception. These residues will inevitably cause serious blockage to the formation and filling layers and greatly reduce the permeability (the cumulative damage can reach more than 90%), thereby greatly reducing the hydraulic pressure. The effect of fracturing (especially for low-pressure, low-permeability oil and gas reservoirs, often resulting in complete failure of fracturing).

[0003] Therefore, under the current situation that oil and gas field development has higher and higher fracturing effects, eliminating residues and their damage has become a major technical problem that needs to be solved urgently. It is also a frontier topic in this industry - clean fracturing fluid (VES) and its application.

[0004] Most of...

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