Water-based drilling fluid with cyclodextrin shale stabilizer

Patent metadata

Field	Value
Publication number	US-9267069-B2
Application number	US-201213670636-A
Country	US
Kind code	B2
Filing date	Nov 7, 2012
Priority date	Nov 7, 2012
Publication date	Feb 23, 2016
Grant date	Feb 23, 2016

Abstract

Well fluids and methods are provided that can be used for stabilizing a shale formation, especially during drilling of a well into or through a shale formation. The well fluids include: (i) a continuous water phase; (ii) a viscosity-increasing agent, wherein the viscosity-increasing agent comprises water-soluble hydrophilic polymer; (iii) a fluid loss control agent; and (iv) a cyclodextrin-based compound. The methods of drilling include the steps of: (A) introducing the well fluid into a zone of a subterranean formation; and (b) drilling the zone.

First claim

What is claimed is:

1. A method of drilling a zone of a well, the method comprising the steps of:
(A) introducing a water-based drilling fluid into the zone, the water-based drilling fluid comprising:
(i) a continuous water phase;
(ii) a viscosity-increasing agent, wherein the viscosity-increasing agent comprises a water-soluble hydrophilic polymer;
(iii) a fluid-loss control agent; and
(iv) a cyclodextrin-based compound; and

(B) drilling in the zone,
wherein the water-based drilling fluid does not include a hydrophobically-modified hydrophilic polymer.

2. The method according to claim 1 , wherein the cyclodextrin-based compound does not interact with the viscosity-increasing agent to increase or decrease the viscosity of the water-based drilling fluid by more than 10 cP.

3. The method according to claim 1 , wherein the water-based drilling fluid has less than a sufficient concentration of a viscoelastic surfactant to increase the viscosity of the water-based drilling fluid by more than 10 cP.

4. The method according to claim 1 , wherein the water-based drilling fluid contains less than 0.01% by weight of the water of a viscoelastic surfactant.

5. The method according to claim 1 , wherein the continuous water phase comprises a source of water selected from the group consisting of freshwater, seawater, brine, or any combination thereof.

6. The method according to claim 1 , wherein the water-based drilling fluid additionally comprises a weighting agent.

7. The method according to claim 6 , wherein the weighting agent is in at least a sufficient concentration such that the continuous water phase has a density of at least 9 ppg.

8. The method according to claim 6 , wherein the weighting agent comprises a water-soluble inorganic salt.

9. The method according to claim 6 , wherein the weighting agent comprises barium sulfate.

10. The method according to claim 6 , wherein the weighting agent is a solid particulate selected from the group consisting of: hematite, calcium carbonate, and any combination thereof.

11. The method according to claim 6 , wherein the weighting agent is a solid particulate having a particle size distribution anywhere in the range of 400 US mesh to 100 US mesh.

12. The method according to claim 1 , wherein the water-based drilling fluid includes less than 10% of any combination of dissolved alkali metal halide salts by weight of the water.

13. The method according to claim 1 , wherein the viscosity-increasing agent comprises a cellulosic polymer, a polyacrylic polymer, or natural gum polymer.

14. The method according to claim 1 , wherein the fluid-loss control agent is selected from the group consisting of: bentonite particulate, an organic colloidal-sized solid particulate; a filter cake bridging material, a lost-circulation particulate, and any combination thereof; and wherein the fluid-loss control agent does not comprise a hydrophobically-modified hydrophilic polymer.

15. The method according to claim 1 , wherein the fluid-loss control agent is a particulate selected from the group consisting of bentonite, a biopolymer, cellulose polymer, modified cellulose, starch, modified starch, polyanionic cellulose, plant tannin, a polyphosphate, a lignitic material, a lignosulfonate, a synthetic polymer, calcium carbonate, asphalt, gilsonite, walnut shells, and mica; and wherein the fluid-loss control agent does not include a hydrophobically-modified hydrophilic polymer.

16. The method according to claim 1 , wherein the fluid-loss control agent is selected from the group consisting of polyanionic cellulose, modified starch, and any combination thereof in any proportion; and wherein the fluid-loss control agent does not include a hydrophobically-modified hydrophilic polymer.

17. The method according to claim 1 , wherein the fluid-loss control agent is in a concentration of at least 1 ppg of the continuous water phase.

18. The method according to claim 1 , wherein the cyclodextrin-based compound is a cyclodextrin.

19. The method according to claim 1 , additionally comprising the step of: forming the water-based fluid.

20. The method according to claim 1 , wherein the zone penetrates or is in a subterranean formation of shale.

21. The method according to claim 1 , wherein the cyclodextrin-based compound stabilizes a shale formation.

22. A method of drilling a zone of a well, the method comprising the steps of:
(A) introducing a water-based drilling fluid into the zone, the water-based drilling fluid comprising:
(i) a continuous water phase;
(ii) a viscosity-increasing agent, wherein the viscosity-increasing agent comprises a water-soluble hydrophilic polymer;
(iii) a fluid-loss control agent; and
(iv) a cyclodextrin-based compound, wherein the cyclodextrin-based compound does not interact with the viscosity-increasing agent to increase or decrease the viscosity of the water-based drilling fluid by more than 10 cP; and

(B) drilling in the zone,

wherein the water-based drilling fluid does not contain a hydrophobically-modified hydrophilic polymer.

Assignees

• Halliburton Energy Services Inc

Inventors

• Wagle Vikrant Bhavanishankar
• Kulkarni Dhanashree Gajanan
• Muthusamy Ramesh

Classifications

• C09K2208/12

  Swell inhibition, i.e. using additives to drilling or well treatment fluids for inhibiting clay or shale swelling or disintegrating · CPC title

• C09K8/08 Primary

  containing natural organic compounds, e.g. polysaccharides, or derivatives thereof · CPC title

• C09K8/032

  Inorganic additives · CPC title

• C09K8/10 Primary

  Cellulose or derivatives thereof · CPC title

• C09K8/5758 Primary

  of natural origin, e.g. polysaccharides, cellulose (C09K8/5756 takes precedence) · CPC title