Borehole treating substance containing ether carboxylic acids

A well servicing composition flowable and pumpable at 5° to 20° C. comprising a continuous oil phase in admixture with a quantity of a disperse aqueous phase of a w/o invert type which optionally contains at least one dissolved auxiliary, dispersed auxiliary, or combinations thereof selected from the group consisting of thickeners, fluid loss additives, wetting agents, fine-particle weighting agents, salts, alkali reserves and biocides, wherein, the composition contains the ether carboxylic acid of compound of formula:

• RO(CH2CH2O)x(CH2CHR1O)yCH2—COOX (I)
• wherein, R is a saturated or unsaturated, branched or unbranched alkyl or alkenyl group containing 6 to 22 carbon atoms, x is a number from 1 to 20 and y is 0 or a number from 1 to 20, provided that the sum of x and y is at least 1 and at most 25, R1 is an alkyl group containing 1 to 4 carbon atoms and X comprises at least one member selected from the group consisting of a hydrogen atom, monovalent cations and polyvalent cations wherein the oil phase comprises at least one member selected from the group consisting of
• (a) carboxylic acid esters of formula:
• R′—COO—R″ (II) where R′ is a saturated or unsaturated, linear or branched alkyl group containing 5 to 23 carbon atoms and R″ is an alkyl group containing 1 to 22 carbon atoms, which may be saturated or unsaturated, linear or branched,
• (b) α-olefins, internal olefins, poly-α-olefins, or combinations thereof,
• (c) water-insoluble, symmetrical or nonsymmetrical ethers of monohydric alcohols of natural or synthetic origin which contain 1 to 24 carbon atoms,
• (d) water-insoluble alcohols of formula:
• R″′—OH (III) where R″′ is a saturated, unsaturated, linear or branched alkyl group containing 8 to 24 carbon atoms,
• (e) carbonic acid diesters,
• (f) paraffins, and
• (g) acetals.