Process for mineral oil production from mineral oil deposits with high deposit temperature

摘要

A two-stage process for mineral oil production from mineral oil deposits with a deposit temperature of more than 70° C. and a salinity of 20 000 ppm to 350 000 ppm, in which an aqueous formulation comprising at least one glucan with a β-1,3-glycosidically linked main chain, and side groups β-1,6-glycosidically bonded thereto and having a weight-average molecular weight Mw of 1.5*106 to 25*106 g/mol, are injected into a mineral oil deposit through at least one injection borehole and crude oil is withdrawn from the deposit through at least one production borehole. The aqueous formulation is prepared in two stages, by first preparing an aqueous concentrate of the glucan, and diluting the concentrate on site with water to the use concentration.

主权项

1. A process for mineral oil production from a deposit with a deposit temperature TL of at least 70° C., wherein the process comprises at least the following process steps:
(1) providing a concentrate (K) of at least one glucan with a β-1,3-glycosidically bonded main chain, and side groups β-1,6-glycosidically bonded thereto and having a weight-average molecular weight Mw of 1.5*106 to 25*106 g/mol, in water with a concentration of more than 3 g/l to 30 g/l, (2) preparing an aqueous formulation (F) comprising the at least one glucan by diluting the concentrate (K) provided in step (1) on site with water to a glucan concentration of 0.05 g/l to 3 g/l, with the proviso that the concentration is selected such that the viscosity ηF measured at 7 s−1 and TL of the aqueous formulation (F) is at least 3 mPa*s, the viscosity ηF being selected in comparison to the viscosity ηoil measured at TL such that ηF≦ηoil, and (3) injecting the aqueous formulation (F) into the mineral oil formation through at least one injection borehole and withdrawing crude oil from the deposit through at least one production borehole,
wherein said deposit comprises oil and deposit water with a salinity of 20 000 ppm to 350 000 ppm, and wherein said oil has a viscosity ηoil measured at TL of at least 3 mPa*s.