Nano-emulsion type efficient cleanup additive

Abstract

The invention discloses a nano-emulsion type efficient cleanup additive and a preparation method thereof and belongs to the technical field of petrochemicals. The nano-emulsion type efficient cleanupadditive is prepared from components in percentage by weight as follows: 20%-25% of a Gemini surfactant, 3%-5% of a solubilizer, 15%-20% of an oil phase, 40%-57% of an aqueous phase and 5%-10% of an inorganic electrolyte. The method comprises the following steps: the Gemini surfactant as a main reagent as well as the solubilizer and the oil phase is added to a reactor; the materials are mixed uniformly, temperature in the reactor is kept at 60-70 DEG C by heating, and then water and the inorganic electrolyte are added; a reaction is performed for 1-2 h under stirring, and a faint yellow transparent liquid is obtained. The nano-emulsion type efficient cleanup additive has a function of repairing reservoir permeability, and compared with the conventional cleanup additive systems, the nano-emulsion type efficient cleanup additive has the advantage that 30% or more of formation damage degree caused by water blocking and residues of immediate vicinity of wellbore and incompatibility of formation fluids in a fracture acidizing process of an oil / gas well can be reduced.

Description

technical field [0001] The invention relates to a nano-emulsion type high-efficiency drainage aid and its preparation method and application, belonging to the technical field of petrochemical industry. Background technique [0002] The proportion of unconventional energy gas (including shale gas, coalbed methane, and tight sandstone gas) in the energy structure is increasing year by year. The development of unconventional energy gas in my country is also in full swing. As an important part of unconventional energy gas, shale gas has achieved a series of achievements but also faces many development problems. my country has huge shale gas reserves. Shale gas reservoirs are characterized by low porosity and low permeability, and the diffusion and migration of gas are slow. Fracturing is a necessary link in the development and production of shale gas wells. However, fracturing will introduce a large amount of fracturing fluid into the shale formation. Due to the low porosity an...

AI Technical Summary

Problems solved by technology

However, fracturing will introduce a large amount of fracturing fluid into shale formations. Due to the characteristics of low porosity and low permeability of shale formations, the problem of liquid phase retention of fracturing fluid is very serious. The liquid will hinder the desorption of shale gas and the migration of gas, reduce the relative permeability of gas phase, and lead to production reduction in wells treated by fracturing

At present, surfactants are mainly used to reduce interfacial tension to solve the flowback problem, but the flowback rate is relatively low, basically below 50%.

Images