In recent years, the extraction of shale gas has developed rapidly, and the recovery efficiency can be improved through transforming the reservoir by hydraulic fracturing technology. A large amount of slickwater will be discharged back to the ground as produced water after reservoir transformation. If the high-salinity produced water is reused and reformulated into slickwater, the environmental pollution and treatment cost can be reduced. As the main part of slickwater, friction reducer plays an important role in reducing construction friction. At present, it is still difficult to make up slickwater by repeated use of high salinity produced water. While ordinary friction reducers are hard to play the friction reducing role in high salinity produced water, and a large number of metal ions make friction reducers curl together through electrostatic compression, which causes the difficulty in forming linear polymer fluid by stretching and hydrating.
Ordinary polyacrylamide emulsion friction reducers also have certain requirements for dissolution water. Recently there emerged a high brine HVFR, which can meet the requirements of flow-back liquid for high salinity liquid preparation. With the good properties of instant dissolution, shear resistance, heat resistance, salt resistance and the drag reduction effect, the product performs good drag-reducing characteristic in the application tests carried out by several customers and can be used as the friction reducer for slickwater.
The high brine HVFR breaks through the limitations of the existing powder products, such as slow dissolution rate, high dosage and low drag reduction efficiency, and also solves the problem that ordinary friction reducers cannot meet the requirements of flow-back liquid for high salinity liquid preparation, which is of great significance for reducing the cost of fracturing construction and saving fresh water resources.