Ethoxylated raw cotton linters for completion and workover fluids

• US 7,622,427 B2
• Filed: 02/21/2007
• Issued: 11/24/2009
• Est. Priority Date: 02/23/2006
• Status: Active Grant

• Current Assignee: Hercules, LLC (Ashland Global Holdings, Inc.)
• Original Assignee: Hercules Incorporated (Ashland Global Holdings, Inc.)
• Inventors: Sau, Arjun C., Melbouci, Mohand
• Primary Examiner(s): Seidleck; James
• Assistant Examiner(s): Figueroa; John J
• Application Number:
  US11/709,183
• Publication Number:
  US 20070197399A1
• Time in Patent Office: 1,007 Days
• Field of Search: None
• US Class Current: 507/204
• CPC Class Codes: C09K 8/04 Aqueous well-drilling compositions
• CPC Class Codes: C09K 8/08 containing natural organic compounds, e.g. polysaccharides, or derivatives thereof
• CPC Class Codes: C09K 8/20 Natural organic compounds or derivatives thereof, e.g. polysaccharides or lignin derivatives

Abstract

A completion and workover fluid composition comprising, water and at least one rheology modifier and/or fluid loss control agent, and at least one other ingredient selected from the group consisting of inorganic salts, shale inhibitors, corrosion inhibitor, biocide, defoamers and finely divided solids particles (e.g., bentonite, attapulgite, sepiolite, calcium carbonate, etc.), depending upon the desired attributes, wherein the rheology modifier and/or the fluid loss control agent is an ethoxylated raw cotton linters or a modified ethoxylated raw cotton linters. The ethoxylated raw cotton linters provides comparable or better rheology and viscosity properties compared to high molecular weight commercial HECs made from purified cotton linters. These ethoxylated raw cotton linters derivatives are suitable for applications in oil-well servicing fluids, particularly to enhance functional properties of completion and workover fluids used during oil-well drilling operations.

Claims

1. A completion and workover fluid composition comprising water and at least one rheology modifier and/or fluid loss control agent, and at least one other ingredient selected from the group consisting of polymeric additive, inorganic salts, shale stabilizers, corrosion inhibitors, weighting agents, and finely divided clay particles wherein the rheology modifier and/or the fluid loss control agent is ethoxylated raw cotton linters (EO-RCL), wherein the EO-RCL has an oxyethylene molar substitution (MS) with a lower limit of about 0.5 and wherein the at least one other ingredient comprises an inorganic salt and wherein the inorganic salt is selected from the group consisting of calcium carbonate, calcium chloride, potassium chloride, sodium chloride, magnesium chloride, sodium bromide, potassium bromide, calcium bromide, zinc bromide, sodium formate, potassium formate, cesium formate and mixtures thereof.

2. The composition of claim 1, wherein the EO-RCL contains an additional substituent.

3. The composition of claim 2 wherein the additional substituent comprises alkyl groups.

4. The composition of claim 3 wherein the alkyl groups contain 1 to 30 carbon atoms.

5. The composition of claim 3 wherein the additional substituent comprises carboxymethyl groups.

6. The completion and workover fluid composition of claim 1, wherein the EO-RCL has an oxyethylene molar substitution (MS) with a lower limit of about 1.5.

7. The completion and workover fluid composition of claim 1, wherein the EO-RCL has an oxyethylene molar substitution (MS) with a lower limit of about 1.8.

8. The completion and workover fluid composition of claim 1, wherein the EO-RCL has an oxyethylene molar substitution (MS) with an upper limit of about 3.5.

9. The completion and workover fluid composition of claim 8, wherein the EO-RCL has an oxyethylene molar substitution (MS) with an upper limit of about 2.5.

10. The completion and workover fluid composition of claim 9, wherein the EO-RCL has an oxyethylene molar substitution (MS) with an upper limit of about 2.2.

11. The completion and workover fluid composition of claim 1, wherein the EO-RCL has an oxyethylene molar substitution (MS) in a range of from about 0.5 to about 3.5.

12. The completion and workover fluid composition of claim 11, wherein the EO-RCL has an oxyethylene molar substitution (MS) in a range of from about 1.5 to 2.5.

13. The completion and workover fluid composition of claim 12, wherein the EO-RCL has an oxyethylene molar substitution (MS) in a range of from about 1.8 to 2.2.

14. The completion and workover fluid composition of claim 1, wherein the composition further comprises a polymeric additive and wherein the polymeric additive is selected from the group consisting of starch and its derivatives, guar gum and its derivatives, xanthan gum, welan gum, diutan gum, cellulose ethers, polyacrylates, polyacrylamides and mixtures thereof.

15. The completion and workover fluid composition of claim 1, wherein the composition further comprises a shale stabilizer or corrosion inhibitor and wherein the shale stabilizer or corrosion inhibitor is selected from the group consisting of partially hydrolyzed polyacrylamides (PHPA), potassium chloride, potassium acetate, potassium carbonate, potassium hydroxide, sulfonated asphalt, blown asphalt, gilsonite, polyglycols, polyamino acids, surfactants, cationic polymers, mixed metal hydroxides (MMH), and mixtures thereof.

16. The completion and workover fluid composition of claim 1, wherein the composition further comprises a weighting agent and wherein the weighting agent is selected from the group consisting of barite, hematite, manganese oxide, sized calcium carbonate made from ground limestone or marble, and mixtures thereof.

17. The completion and workover fluid composition of claim 1, wherein the composition further comprises finely divided clay particles and wherein the finely divided clay particles are selected from the group consisting of bentonite, attapulgite, sepiolite, saponite, and mixtures thereof.

18. The completion and workover fluid composition of claim 1, wherein the composition further comprises a lubricant and wherein the lubricant is selected from the group consisting of glycol, asphalt, and mixtures thereof.

19. The completion and workover fluid composition of claim 1, further comprising a biocide.

20. The completion and workover fluid composition of claim 1, further comprising a defoamer.