Claims
- 1. A drilling fluid composition for mud wall formation which comprises 100 weight parts of an aqueous medium, 1-10 weight parts of an inorganic substance comprising bentonite, and 0.1-2 weight parts of a drilling fluid additive, wherein the drilling fluid additive is composed of a water-soluble copolymer (A) which has an average molecular weight of 1,000 to 50,000, said water-soluble copolymer (A) being obtained by polymerization of monomer components containing 40-99.5 mole % of an unsaturated carboxylic acid monomer of the formula I ##STR4## wherein A.sup.1 and A.sup.2 independently represents hydrogen, methyl or --COOX.sup.2, with the proviso that A.sup.1 and A.sup.2 cannot both be --COOX.sup.2 ; A.sup.3 represents hydrogen, methyl or --CH.sub.2 COOX.sup.3 and, in case where A.sup.3 is --CH.sub.2 COOX.sup.3, each A.sup.1 and A.sup.2 independently represents hydrogen or methyl; and X.sup.1, X.sup.2 and X.sup.3 independently represents hydrogen, monovalent metal, divalent metal, ammonium or an organic amine, and 0.5-60 mole % of an unsaturated (meth)allyl ether monomer of the formula II ##STR5## wherein R represents hydrogen or methyl and Z represents hydroxyl, a sulfonic acid group or its monovalent metal salt, divalent metal salt, ammonium salt or organic amine salt, a phosphoric or phosphorous acid group or its monovalent metal salt, divalent metal salt, ammonium salt or organic amine salt.
- 2. The drilling fluid composition of claim 1, wherein the monomer of the unsaturated carboxylic acid of the formula I are (meth)acrylic acid, maleic acid, salts thereof or mixture thereof.
- 3. The drilling fluid composition of claim 1, wherein the unsaturated monomer of the (meth)allyl ether is selected from the group consisting of glycerol monoallyl ether, 3-allyloxy-2-hydroxypropanesulfonic acid, salts thereof and mixtures thereof.
- 4. The drilling fluid composition of claim 1, further comprising at least one auxiliary additive selected from the group consisting of carboxymethylcellulose and aluminates.
- 5. The drilling fluid composition of claim 4 containing 1-10 weight parts of the inorganic comprising bentonite substance and 0.1-2 weight parts of the drilling fluid additive per 100 weight parts of the aqueous medium and 5-500 weight parts of the at least one auxiliary additive per 100 parts of the water-soluble copolymer (A).
Priority Claims (1)
Number |
Date |
Country |
Kind |
63-281262 |
Nov 1988 |
JPX |
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Parent Case Info
This application is a continuation of application Ser. No. 07/817,986, filed Jan. 8, 1992, now abandoned, which is a continuation of application Ser. No. 07/432,822, , filed Nov. 7, 1989, and now abandoned.
US Referenced Citations (9)
Foreign Referenced Citations (3)
Number |
Date |
Country |
0202995 |
Nov 1986 |
FRX |
0144140 |
Jun 1985 |
GBX |
0215565 |
Mar 1987 |
GBX |
Non-Patent Literature Citations (1)
Entry |
Grim, R. E. "Clays (Uses)" Kirk-Othmer Encyclopedia of Chemical Technology, 3rd Ed. 1979, N.Y. Wiley & Sons, pp. 207-223, Ref TP9 E68 1978. |
Continuations (2)
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Number |
Date |
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Parent |
817986 |
Jan 1992 |
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Parent |
432822 |
Nov 1989 |
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