Composition of microemulsion and method for advanced recovery of heavy oil
AssigneePetroleo Brasileiro S.A. - Petrobras
InventorsMarcia Cristina Khalil Oliveira, Gaspar Gonzalez Maldonado
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Abstract
A composition of a microemulsion including a mixture of a combination of surfactants and co-surfactants, an oil phase and an aqueous phase is described. In addition, a method for the advanced recovery of heavy oils is described which includes the steps of injecting a bank containing a microemulsion composition, injecting a bank of a polymer solution, and injecting water. The microemulsion composition can be applied in arenitic and carbonatic reservoirs, containing oils with API below 22.3° API, in both onshore and offshore fields.
Claims10
A microemulsion composition comprising a mixture of:
- a) between 15% and 30% by volume based on the total volume of the microemulsion composition of a combination of surfactants and co-surfactants wherein the mass ratio between the co-surfactant and the surfactant vary from 0.5 to 1.0;
- b) between 10% and 30% by volume based on the total volume of the microemulsion composition of an oil phase;
- and
- c) an aqueous phase sufficient to complete 100% by volume of the microemulsion composition;
A method for the advanced recovery of heavy oil, comprising the steps of:
- a) Making contact between a heavy oil contained in a reservoir and a microemulsion composition by means of injection in injector wells drilled in the reservoir from a bank containing the microemulsion composition which comprises a mixture of:
- i. A combination of surfactants and co-surfactants representing between 15% and 30% by volume of the total volume of the composition of microemulsion, where the mass ratio between the co-surfactants and the surfactants is between 0.5 and 1.0;
- ii. An oil phase representing between 10% and 30% by volume of the total volume of the microemulsion composition;
- and
- iii. An aqueous phase sufficient to complete 100% by volume of the composition of microemulsion;
- b) Displacing the bank containing the microemulsion composition by means of a subsequent injection of a bank of a polymer solution;
- c) Moving the bank of polymer solution by means of a subsequent injection of water;
- d) Recovering the heavy oil by means of producer wells drilled in the reservoir.
Dependencies are inferred from the claim text.