Drag reducer with high stability as well as preparation method and application thereof

Abstract

The invention provides a drag reducer with high stability. The drag reducer is prepared from the following raw materials in parts by weight: 40-60 parts of an acrylamide monomer, 1-5 parts of a cross-linking agent, 1-5 parts of a dispersing agent, 30-50 parts of water, 40-70 parts of an oil solvent, 30-60 parts of a surfactant and 0.5-0.9 part of an initiator, wherein the cross-linking agent adopts a glycidyl ether type cross-linking agent and a polyamine type cross-linking agent. The drag reducer provided by the invention is convenient to use on site, high in dissolving speed and good in saltresistance, and the product stability can reach 7 months. Compared with a common emulsion drag reducer, the product performance is improved, and long-term storage and long-distance transportation canbe better met.

Description

technical field [0001] The application relates to the technical field of oilfield chemicals, in particular to a highly stable drag reducer and its preparation method and application. Background technique [0002] Fracturing is an important technology in the field of oil and gas field development, and fracturing fluid plays a decisive role in the process of fracturing. With the development of fracturing technology and the research and development of fracturing fluid, slick water fracturing fluid has been widely used because of its low viscosity and low friction. [0003] Drag reducer is a key component in slick water fracturing fluid, which largely determines the performance of slick water fracturing fluid, especially for shale reservoirs with low porosity and low permeability. The amount of the drag reducer is large, and it needs to flow back after pressure, so the performance of the drag reducer is also required. At present, polyacrylamide drag reducing agents have become...

AI Technical Summary

Problems solved by technology

[0004] However, the existing polyacrylamide drag reducers still have the following problems: when formulated into slick water for use in low-porosity and low-permeability shale reservoirs, the sand-carrying capacity is limited, which is not conducive to the dispersion of proppant; Contains a large amount of salt ions, such as Na + , Mg 2+ , Ca 2+ , while the drag reduction rate of existing polyacrylamide-based drag reducers drops significantly in the flowback liquid containing salt ions, that is, the salt resistance is poor; while the existing polymers with good salt resistance or good sand-carrying ability The drag reducer has a large molecular weight and viscosity, and is prone to adsorption and retention in the rock fracture wall and matrix pores, thereby causing great damage to the shale reservoir; the emulsion drag reducer that has not been formulated into slick water has a short stability time at room temperature. Delamination usually occurs in about 2 months, greatly weakening its drag reduction ability, which is not conducive to long-term storage and long-distance transportation. If it is directly made into slippery aquatic products, the selectivity is small, and it is not convenient for on-site preparation and use. Limitations its application

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