Patent ID: 6242389
Filing Date: 2001-06-05
Classification: C07C,C09K

Abstract:
An aqueous drilling fluid which comprises a composition comprising a mixture of glycol ether block copolymer wherein said mixture has an average formula IR--O--[[--R.sup.1 O].sub.m [--R.sup.11 O].sub.n [--R.sup.111 O].sub.p ]H Iwherein either the --R.sup.1 O or the --R.sup.11 O groups are directly bonded to the R--O group, and the R.sup.111 O group is spaced from the RO group by the R.sup.11 O group and the R.sup.1 O group, and is different from the group R.sup.11 O or R.sup.1 O group to which it is bonded directly, R is an organic group, R.sup.1 is an ethylene group, R.sup.11 is selected from the group consisting of a propylene and butylene groups, R.sup.111 is selected from the group consisting of an ethylene, propylene and butylene groups, m is an average of 1.0-10, n is an average of 1.0-10, p is either 0 or an average of 0.5-5.0, and the sum of m and n is at least 3.0, a water soluble calcium salt and water.