US 12,760,214 B2 · Viscoelastic foam system for acidic gas switch, and method and use for improving the recovery factor using the same

Abstract

A viscoelastic foam system for an acidic gas switch improves the recovery factor. The viscoelastic foam system for an acidic gas switch has a pH-switch surfactant, a hydrocarbyl anionic surfactant and water. The pH-switch surfactant is at least one of long-chain hydrocarbyl amines. After the viscoelastic foam system meets the acidic gas, the interaction between the pH-switch surfactant and the hydrocarbyl anionic surfactant is enhanced, the viscosity increases, and the formed foam has better stability and plugging performance. When the viscoelastic foam system is injected at 1.0 PV, the apparent viscosity of the foam formed in the rock core is ≥270 mPa·s, which can increase the recovery factor by more than 20%, and the long-chain hydrocarbyl amine improves the salt tolerance of the single anionic surfactant, so that the applicable mineralization range of the system is increased to 10-200 g/L.

Claims19

Dependent claims

A viscoelastic foam system for an acidic gas switch, comprising a pH-switch surfactant, and a hydrocarbyl anionic surfactant and water,

wherein the pH-switch surfactant is at least one of long-chain hydrocarbyl amines selected from compounds of formula (1), formula (Ia), formula (Ib), and formula (Ic):
wherein R1 is each independently selected from C11-C24 aliphatic hydrocarbyls;
R2 is each independently selected from C1-C5 aliphatic hydrocarbyls;
R3, R4 and R5 are each independently selected from H, C1-C3 aliphatic hydrocarbyls, and substituted C1-C3 aliphatic hydrocarbyls;
m+n+p is 1-30, q is 1 or 2;
and
L is a bivalent linking group selected from —CO—, —CO—NH—, —CO—NH—CO—, —CO—NH—COO—, —CO—NH—OCO—, —COO—, —COO—NH—, —COO—NH—CO—, —COO—NH—COO—, —NHCO—, —NHCONH—, —NHCOO—, —NHOCO—, —OCONH—, —OCO—NH—CO—, —OCO—NH—OCO—, —OCOO—, —O—SO2—, —SO2—, and —O—.

4 more elements

Dependencies are inferred from the claim text.

Viscoelastic foam system for acidic gas switch, and method and use for improving the recovery factor using the same

Life of this patent

Viscoelastic foam system for acidic gas switch, and method and use for improving the recovery factor using the same

Life of this patent

Abstract

Claims19