Method of concurrent oil extraction and carbon dioxide mineralization

1 . A method of concurrent oil extraction and carbon dioxide (CO 2 ) mineralization, comprising:

injecting a solution comprising seawater and hexamethylenediamine (HMDA) into a wellbore bored in an underground geological formation comprising basalt rocks,

wherein HMDA is present in the solution at a weight percentage of 0.1 to 1.0 wt. % based on a total weight of the solution;

flowing a CO 2 -containing gas into the solution to form a carbonated solution submerged in the underground geological formation, wherein the CO 2 -containing gas comprises mainly CO 2 ;

injecting a basic solution into the carbonated solution to precipitate a plurality of carbonate minerals and form a treated water,

wherein the basic solution comprises sodium hydroxide at a weight percentage of 1 to 2 wt. % based on a total weight of the basic solution, and

wherein the carbonate minerals comprise calcite and halite and are in the form of particles;

flooding the underground geological formation with the treated water under an ambient pressure, wherein the underground geological formation further comprises crude oil; thereby

extracting the crude oil from the underground geological formation.

2 . The method of claim 1 , wherein the seawater comprises a total dissolved solid at a concentration of 50,000 to 80,000 ppm and a plurality of ions comprising:

sodium ions (Na + ), at a concentration of 15,000 to 25,000 ppm;

calcium ions (Ca 2+ ), at a concentration of 500 to 1,500 ppm;

magnesium ions (Mg 2+ ), at a concentration of 2,000 to 4,000 ppm;

sulfate ions (SO 4 2− ), at a concentration of 2,000 to 5,000 ppm;

chloride ions (Cl − ), at a concentration of 30,000 to 50,000 ppm; and

bicarbonate ions (HCO 3 − ), at a concentration of 100 to 500 ppm.

3 . The method of claim 1 , wherein HMDA is present in the solution at a weight percentage of 0.1 to 0.5 wt. % based on the total weight of the solution.

4 . The method of claim 3 , wherein the carbonated solution comprises a total inorganic carbon at an amount of 1000 to 1500 mg/L, and the carbonated solution uptakes CO 2 at an amount of 4.0 to 5.0 g/L.

5 . The method of claim 3 , wherein the carbonate minerals are precipitated in an amount of 10 to 15 grams per 1 liter of the carbonated solution, comprising:

calcite, at a weight percentage of 45 to 65 wt. %; and

halite, at a weight percentage of 50 to 60 wt. %, based on the total weight percentage of the carbonate minerals, and

wherein the carbonate minerals comprise porous globular aggregates having an irregular shape and a particle size of 2 to 10 μm.

6 . The method of claim 3 , wherein the treated water exhibits a zeta potential over a limestone rock of −5 to −1 mV, a zeta potential over oil of −30 to −25 mV and an interfacial tension of 6.0 to 6.5 mN/m.

7 . The method of claim 3 , wherein the submerging of the underground geological formation in the treated water forms an aged underground geological formation having a water contact angle of 15° to 20°.

8 . The method of claim 3 , having an oil recovery rate of 45 to 50% after 20 to 30 days.

9 . The method of claim 1 , wherein HMDA is present in the solution at a weight percentage of 0.5 to 0.7 wt. % based on the total weight of the solution.

10 . The method of claim 9 , wherein the carbonated solution comprises a total inorganic carbon at an amount of 1500 to 2000 mg/L, and the carbonated solution uptakes CO 2 at an amount of 7.0 to 8.0 g/L.

11 . The method of claim 9 , wherein the carbonate minerals are precipitated at a weight of 15 to 20 grams per 1 liter of the carbonated solution, comprising:

halite, at a weight percentage of 85 to 99 wt. %; and

calcite, at a weight percentage of 1 to 5 wt. %, based on the total weight percentage of the carbonate minerals, and

wherein the carbonate minerals comprise a faceted and angular morphology having a layered structure, wherein the particles have a bimodal size distribution with a particle size of 10 to 20 μm.

12 . The method of claim 9 , wherein the treated water exhibits a zeta potential over a limestone rock of −6.0 to −5.0 mV, a zeta potential over oil of −15 to −10 mV and an interfacial tension of 4.5 to 6.0 mN/m.

13 . The method of claim 9 , wherein the submerging of the underground geological formation in the treated water forms an aged underground geological formation having a water contact angle of 25° to 35°.

14 . The method of claim 9 , having an oil recovery rate of 45 to 50% after 20 to 30 days.

15 . The method of claim 1 , wherein HMDA is present in the solution at a weight percentage of 0.7 to 1.0 wt. % based on the total weight of the solution.

16 . The method of claim 15 , wherein the carbonated solution comprises a total inorganic carbon at an amount of 3000 to 4000 mg/L, and the carbonated solution uptakes CO 2 at an amount of 10 to 15 g/L.

17 . The method of claim 15 , wherein the carbonate minerals are precipitated at a weight of 7.0 to 10.0 grams per 1 liter of the carbonated solution, comprising:

halite, at a weight percentage of 75 to 95 wt. %;

calcite, at a weight percentage of 10 to 15 wt. %, based on the total weight percentage of the carbonate minerals, and

wherein the carbonate minerals comprise a plurality of amorphous particles having a particle size of 15 to 50 μm.

18 . The method of claim 15 , wherein the treated water exhibits a zeta potential over a limestone rock of −0.5 to −0.1 mV, a zeta potential over oil of −10 to −5 mV and an interfacial tension of 3.5 to 5.0 mN/m.

19 . The method of claim 15 , wherein the submerging of the underground geological formation in the treated water forms an aged underground geological formation having a water contact angle of 40° to 50°.

20 . The method of claim 15 , having an oil recovery rate of 35 to 40% after 20 to 30 days.