In situ generation of nano-clay drilling fluid

Patent metadata

Field	Value
Publication number	US-2017275519-A1
Application number	US-201615077656-A
Country	US
Kind code	A1
Filing date	Mar 22, 2016
Priority date	Mar 22, 2016
Publication date	Sep 28, 2017
Grant date	—

Abstract

A method includes adding a clay to water to form a suspension of clay in water, the clay including pieces of clay having an average diameter of at least 2 μm; adding a dispersant to the suspension of clay in water to form a drilling fluid; and injecting the drilling fluid into a well. In the drilling fluid, the dispersant interacts with the clay to form nanoscale particles of clay having an average diameter of less than 500 nm.

First claim

What is claimed is:

1 . A method comprising:
adding a clay to water to form a suspension of clay in water, the clay including pieces of clay having an average diameter of at least 2 μm; adding a dispersant to the suspension of clay in water to form a drilling fluid; and injecting the drilling fluid into a well; wherein in the drilling fluid, the dispersant interacts with the clay to form nanoscale particles of clay having an average diameter of less than 500 nm.

2 . The method of claim 1 , comprising soaking the clay in water for at least about 2 hours.

3 . The method of claim 1 , wherein the clay comprises bentonite.

4 . The method of claim 1 , wherein the dispersant comprises an anionic polymer.

5 . The method of claim 1 , wherein the dispersant comprises chrome lignosulfonate or a chrome-free lignosulfonate.

6 . The method of claim 1 , wherein the dispersant comprises a polyacrylamide.

7 . The method of claim 1 , wherein the dispersant comprises one or more of anionic polyacrylates, polymers of allyloxybenzenesulfonate monomers, sulfonated isobutylene maleic anhydride copolymers, polymers containing maleic anhydride, complexes of aluminum and citric acid, sulfonated napthol compounds, azolignosulfonates, sodium acid pyrophosphate, and complexes of tetravalent zirconium and ligands of an organic acid.

8 . The method of claim 1 , wherein the pH of the drilling fluid is between about 8 and about 12.5.

9 . The method of claim 1 , comprising mixing the drilling fluid, wherein the dispersant interacts with the clay to form the nanoscale particles of clay during the mixing.

10 . The method of claim 9 , wherein the mixing occurs in the well.

11 . The method of claim 8 , wherein the mixing occurs prior to injecting the drilling fluid into the well.

12 . The method of claim 1 , wherein adding a dispersant comprises adding a quantity of the dispersant such that a weight ratio of clay to dispersant in the drilling fluid is between 0.25 and 1.

13 . The method of claim 1 , wherein adding a dispersant comprises adding a weight concentration of the dispersant in water of between 1% and 10%.

14 . The method of claim 1 , wherein adding a clay to water comprises adding a weight concentration of the clay in water of between 0.1% and 10%.

15 . The method of claim 1 , comprising adding a starch to the drilling fluid.

16 . The method of claim 1 , comprising adding one or more of XC-polymer, potassium chloride, potassium hydroxide, lime, a weighting agent, a shale inhibitor, sodium sulfite, polyanionic cellulose, caustic soda, and calcium chloride to the drilling fluid.

17 . The method of claim 1 , wherein the drilling fluid including the nanoscale particles of clay has a plastic viscosity of less than about 60 cP.

18 . The method of claim 1 , wherein the drilling fluid including the nanoscale particles of clay has a yield point of at least 10 lb/100 ft 2 .

19 . The method of claim 1 , wherein in the well, the drilling fluid including the nanoscale particles of clay forms a filter cake having a thickness of less than 6 mm.

20 . A drilling fluid prepared by a process comprising:
adding a clay to water to form a suspension of clay in water, the clay including pieces of clay having an average diameter of at least 2 μm; adding a dispersant to the suspension of clay in water to form a drilling fluid; and injecting the drilling fluid into a well; wherein in the drilling fluid, the dispersant interacts with the clay to form nanoscale particles of clay having an average diameter of less than 500 nm.

21 . The drilling fluid of claim 20 , wherein the process comprises soaking the clay in water for at least 2 hours.

22 . The drilling fluid of claim 20 , wherein the clay comprises bentonite.

23 . The drilling fluid of claim 20 , wherein the dispersant comprises chrome lignosulfonate or chrome-free lignosulfonate.

24 . The drilling fluid of claim 20 , wherein the dispersant comprises polyacrylamide.

25 . The drilling fluid of claim 20 , wherein the dispersant comprises one or more of anionic polyacrylates, polymers of allyloxybenzenesulfonate monomers, sulfonated isobutylene maleic anhydride copolymers, polymers containing maleic anhydride, complexes of aluminum and citric acid, sulfonated napthol compounds, azolignosulfonates, sodium acid pyrophosphate, and complexes of tetravalent zirconium and ligands of an organic acid.

26 . The drilling fluid of claim 20 , wherein the process comprises mixing the drilling fluid, wherein the dispersant interacts with the clay to form the nanoscale particles of clay during the mixing.

27 . The drilling fluid of claim 20 , wherein a weight ratio of clay to dispersant in the drilling fluid is between 0.25 and 1.

28 . The drilling fluid of claim 20 , wherein a weight concentration of the dispersant in water of between 1% and 10%.

29 . The drilling fluid of claim 20 , wherein a weight concentration of the clay in water of between 0.1% and 10%.

30 . The drilling fluid of claim 20 , wherein the drilling fluid comprises starch.

31 . The drilling fluid of claim 20 , wherein the drilling fluid comprises one or more of XC-polymer, potassium chloride, potassium hydroxide, lime, barite weighting agent, a shale inhibitor, sodium sulfite, polyanionic cellulose, caustic soda, and calcium chloride.

Assignees

• Saudi Arabian Oil Co

Inventors

• Al-Yami Abdullah Saleh Hussain
• Wagle Vikrant Bhavanishankar
• Alabdullatif Ziad Abdullrahman Saleh
• Almassi Faramak
• Bubshait Abdulaziz S
• Al Safran Ali Mohammed Hussain

Classifications

• C09K8/18 Primary

  characterised by the organic compounds · CPC title

• C09K8/24 Primary

  Polymers · CPC title

• C09K8/206

  Derivatives of other natural products, e.g. cellulose, starch, sugars · CPC title

• E21B21/003

  Means for stopping loss of drilling fluid (plastering the borehole wall E21B33/138) · CPC title

• C09K2208/10

  Nanoparticle-containing well treatment fluids · CPC title