System for treating an underground formation

1. A method of treating an underground formation of an oil reservoir, comprising the sequential steps of

a) contacting the formation with an aqueous medium,

b) contacting the underground formation with a hydrocarbon fluid,

c) contacting the underground formation with a solvent in the form of a glycol ether,

d) contacting the underground formation with a first consolidation constituent solution, mainly comprising a poly epoxy resin derived from bisphenols, or a poly phenolic resin (novolac resins), in a solvent mainly comprising a glycol ether, in an epoxy resin concentration of from 25 to 75% (mass) and having a viscosity in the range of from 10 to 100 mPa.s,

e) contacting the underground formation with second consolidation constituent substantially homogenous solution mainly comprising a curing agent in a solvent mainly comprising a hydrocarbon fluid, said curing agent occurring in a concentration in the range of from 0.5 to 20% (mass), and the solution having a viscosity such, that the ratio between the viscosity of the solution in step (d) and of the solution in step (e) is in the range of from 1.0 to 5.

2. The method of claim 1 , wherein the epoxy resin solution is selected from a solid or liquid at 23° C., epoxy-novolac resin.

3. The method of claim 2 , wherein the epoxy resin solution is a solid epoxy novalac resin.

4. The method of claim 1 , wherein the curing agent is selected from aliphatic polyamines, alkyl-aryl polyamines and more preferably diethylene toluene diamine (DETDA).