Patent ID: 11891562
Assignee: EQUUS UK TOPCO LTD
Field: Basic materials chemistry (Chemistry)
Classification: CPC C  E | IPC C  E

Claim 17:
18. A method comprising lubricating a drill bit with a drilling fluid comprising:
a) an aqueous brine phase;
b) a particulate solid phase;
c) a compound comprising a dimer and/or trimer fatty residue and an alkyleneoxy chain comprising a first ethyleneoxy section, a second ethyleneoxy section, and a propyleneoxy section located between the first ethyleneoxy section and the second ethyleneoxy section, wherein the propyleneoxy section comprises from 1 to 20 propyleneoxy groups; and
d) optionally, one or more additives selected from rheology modifiers, fluid loss control agents, shale inhibitors, gas hydrate inhibitors and dispersants;
wherein the drilling fluid is suitable for lubricating a drill bit during drilling in a geological formation, and
wherein the compound c) is a compound of the formula (I):

RI[(EO)p(PO)q(EO)r]nR2  (I)

wherein:
R1 is a residue of at least one of: a dimer fatty diacid, a trimer fatty triacid, a dimer fatty diol and/or a trimer fatty triol;
R2 is H or (CO)xR3 where x is 0 or 1 and R3 is a C1 to C6 aliphatic hydrocarbyl group;
EO is an ethyleneoxy group;
PO is a propyleneoxy group;
p is from 1 to 20;
q is from 1 to 20;
r is from 1 to 20;
n is from 1 to 3;
a weight ratio of R1 to total ethyleneoxy and propyleneoxy groups in compound c) is 0.2:1 to 0.6:1; and
wherein the ratio of (p+r) to q is from 0.5 to 8:1.