NANOFIBRILLATED CELLULOSE FOR USE IN FLUIDS FOR ENHANCED OIL RECOVERY
The present invention relates to nanofibrillated cellulose (NFC) for use as viscosity modifier in fluids for enhanced oil recovery. The fluids contain NFC with an aspect ratio of less than 1000 where the nanofibrils have a diameter between 5 and 50 nanometer and a length of less than 10 μm.
1 - 6 . (canceled)
7 . A fluid for use in enhanced oil recovery, wherein the fluid contains, as viscosity modifier, nanofibrillated cellulose (NFC) with an aspect ratio of less than 1000 where the nanofibrils have a diameter between 5 and 50 nanometer and a length of less than 10 μm, wherein the NFC has a surface charge of carboxyl groups in a concentration of less than 0.5 mmol per gram of NFC.
8 . A fluid as claimed in claim 7 , wherein the aspect ratio of NFC is less than 500 where the nanofibrils have a diameter between 5 and 30 nanometer and a length of less than 5 μm.
9 . A fluid as claimed in claim 7 , wherein the NFC is nanofibrillated lignocellulose having a lignin content of up to 25 wt % based on dry matter.
10 . A fluid as claimed in claim 9 , wherein the NFC is nanofibrillated lignocellulose having a lignin content of up to 10 wt % based on dry matter.