A high-efficiency foaming agent for acid CO2 foam fracturing system

Abstract

The invention discloses an acidic CO2 foam fracturing system high-efficiency foaming agent suitable for the CO2 foam fracturing system of gas wells in the Ordos Basin. It is characterized in that: the foaming agent is prepared from the following raw materials in mass percentage: 38- 42% zwitterionic surfactant A, 40-45% zwitterionic surfactant B, 5-8% amphoteric gemini surfactant, 0.3-0.5% polymer, and the balance is solvent. The invention has excellent foaming performance, good foam stabilizing effect, strong salt resistance, oil resistance, temperature resistance and acid resistance, and can meet the foaming requirements of gas well CO2 foam fracturing.

Description

technical field [0001] The invention relates to a gas well acidic CO 2 Formulation of blowing agents for foam fracturing, especially an acidic CO 2 High-efficiency foaming agent for foam fracturing systems. Background technique [0002] CO 2 Foam fracturing fluid is a high-quality and low-damage fracturing fluid system with high viscosity, strong ability to carry sand and suspend sand, low filtration loss, low friction, clean fracturing fractures, less damage to reservoirs, easy flowback, and fracturing It has the characteristics of high fracturing fluid efficiency, and is especially suitable for fracturing stimulation of low pressure, low permeability and water sensitive reservoirs. Foam quality is the effect of CO 2 One of the main factors of foam fracturing fluid performance, the effect of foam quality on CO 2 The viscosity of the foam system has a great influence, and the viscosity increases rapidly with the increase of the foam quality, and the quality of the foam ...

AI Technical Summary

Problems solved by technology

The foaming agents used in conventional fracturing are mostly anionic surfactant system or cationic surfactant system, the foaming agent of anionic surfactant system is incompatible with high salinity fracturing fluid and formation water, while The foaming agent of the cationic surfactant system is seriously absorbed by the sandstone formation rock, which affects the foaming ability and foam stabilization effect of the foam fracturing fluid

Moreover, the foaming agent used in conventional fracturing has poor acid resistance and temperature resistance, and is not suitable for acid CO2 in medium-high temperature gas well reservoirs. 2 foam fracturing

[0005] Chinese patent 89108127.5 discloses a foaming agent for preparing foam fracturing fluid. The foaming agent mainly uses anionic surfactant as the main raw material and is incompatible with acidic fracturing fluid and formation water. The viscosity is greatly reduced, which affects the cross-linking effect and sand-carrying performance of acidic fracturing fluid

[0006] Chinese patent 03104739.4 discloses a novel foaming agent for fracturing, which is composed of zwitterionic surfactants, anionic surfactants and low-molecular alcohols. The incompatibility of the acidic fracturing fluid system greatly reduces the viscosity of the acidic fracturing fluid, which affects the crosslinking effect and sand-carrying performance of the acidic fracturing fluid