Anti -resistant agent and its preparation method, and slippery water pressure cracks and applications

Abstract

The invention relates to the technical field of fracturing fluids, and discloses a drag reducer, a preparation method thereof, and slick water fracturing fluids and applications. The drag reducer contains a structural unit shown in formula (1) and a structural unit shown in formula (2) or formula (3); m is 20000-28000, n 1 90‑130, n 2 50-80; the weight-average molecular weight of the drag reducer is 1.5 million-2 million; the slick water fracturing fluid has good temperature resistance and shear resistance, and has a good drag reduction effect;

Description

Drag reducing agent and preparation method thereof, and slick water fracturing fluid and application technical field The present invention relates to fracturing fluid technical field, be specifically related to a kind of drag reducing agent and preparation method thereof and slick water fracturing fluids and applications. Background technique [0002] As a high-efficiency energy source, petroleum plays an important role in the development of the national economy. Ultra-low permeability, tight reservoir The pore structure is complex, the physical properties of the reservoir are poor, most of the reservoirs are micro-nano-scale pore throats, and it is difficult to produce matrix reserves. The recovery rate of flooding development is low, and most oilfields are developed by fracturing. The type selection of fracturing fluid often depends on reservoir properties, and the more commonly used water-based fracturing fluid systems in oil fields are mainly water-based fracturin...

AI Technical Summary

Problems solved by technology

At present, the research on slick water fracturing fluid mainly lies in the optimization of drag reducer. Take the emulsion type polyacrylamide drag reducer which is easy to mix as an example. Although the dissolution rate is fast, the shear resistance effect is poor. Under continuous shearing for 20 minutes, the drag reduction rate drops from 75% to below 60%

Conventional powder-type pure polyacrylamide drag reduction agent can achieve a drag reduction rate of 70% or even more than 75% at high displacement, but the temperature resistance effect is poor, and the polymer chain is severely sheared when it exceeds 90°C. Resistivity less than 50%

At present, the slick water fracturing fluid is limited by factors such as drag reduction effect, temperature resistance and shear resistance, and there is no relatively mature slick water fracturing fluid that can take into account both drag reduction and temperature resistance and shear resistance.

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