Preparation method of oil displacement type water-based fracturing fluid

Abstract

The invention provides the preparation method of the oil displacement type water-based fracturing fluid, the oil displacement type water-based fracturing fluid has dual effects of fracturing fluid and an oil displacement agent, the problem of adsorbability damage of a conventional cationic VES clean fracturing fluid in the oil and gas reservoir exploitation process is solved, the single well fracturing oil increasing efficiency is improved, and the oil displacement type water-based fracturing fluid has good actual operability. The oil displacement type water-based fracturing fluid is prepared from a nonionic surfactant, an amphoteric surfactant, an anionic surfactant, a chelating agent, inorganic salt, water and a nano material. The nonionic surfactant is one of palm oil diethanolamide or coconut oil diethanolamide; the ampholytic surfactant is one or two of hydroxysulfobetaine or carboxyl betaine; the anionic surfactant is one or two of triethanolamine petroleum sulfonate, dodecylbenzene sulfonic acid or sodium dodecyl sulfate; the chelating agent is sodium ethylene diamine tetracetate; the inorganic salt is potassium chloride or ammonium chloride; and the particle size of the nano material is 10-50nm.

Description

technical field [0001] The invention belongs to the technical field of fracturing stimulation in oil and gas fields, and in particular relates to a method for preparing an oil-displacement water-based fracturing fluid. Background technique [0002] Fracturing is one of the main means of oil and gas reservoir development, fracturing fluid is the working fluid of fracturing construction, and its performance directly affects the efficiency of fracturing construction. The third-low reservoir has the characteristics of "low pressure, low permeability and low porosity". Generally, vegetable gum fracturing fluid has defects such as large residue, difficult gel breaking at low temperature, and low flowback efficiency, so it is difficult to adapt to the fracturing of this type of reservoir. . VES cationic clean fracturing fluid has the advantages of small residue and fast gel breaking, and is especially suitable for fracturing in this type of reservoir. However, the low flowback eff...

AI Technical Summary

Problems solved by technology

The third low oil reservoir has the characteristics of "low pressure, low permeability and low porosity". Generally, vegetable gum fracturing fluid has defects such as large residue, difficult gel breaking at low temperature, and low flowback efficiency, so it is difficult to adapt to the fracturing of this type of reservoir.

However, the patent still has the following deficiencies: (1) Since the fracturing fluid uses a hydrophobic polymer as the thickener of the fracturing fluid, a gel breaker must be added to achieve the gel breaking of the fracturing fluid, so it is difficult to solve the low temperature environment (2) Amphoteric surfactants (betaine or amine oxide) are used as oil displacement agents to make the fracturing fluid have oil displacement effect, but its salt resistance is poor, and it is very difficult in the reservoir environment. It is difficult to automatically form worm-like micelles with a certain viscoelasticity, which reduces the sweeping range of the fracturing glue-breaking fluid and the effect of oil displacement, and it is difficult to meet the requirements of new technologies for on-site construction

Images