Deep-well polysulfonate drilling fluid and preparation method thereof

Patent metadata

Field	Value
Publication number	US-9926482-B1
Application number	US-201715795792-A
Country	US
Kind code	B1
Filing date	Oct 27, 2017
Priority date	Jul 12, 2017
Publication date	Mar 27, 2018
Grant date	Mar 27, 2018

Abstract

The present invention relates to the deep-well drilling fluid field, and discloses a deep-well polysulfonate drilling fluid and a method for preparing the deep-well polysulfonate drilling fluid. The drilling fluid contains water, bentonite, sodium carbonate, sulfomethylated phenolic resin, sulfonated lignite, halide salt, filtrate reducer, sodium polyacrylate, sodium bisulfite and barite, wherein, based on 100 parts by weight of water, the content of the bentonite is 3.5-5 parts by weight, the content of the sodium carbonate is 0.15-0.35 parts by weight, the content of the sulfomethylated phenolic resin is 6-8 parts by weight, the content of the sulfonated lignite is 6-8 parts by weight, the content of the halide salt is 7.5-12 parts by weight, the content of the filtrate reducer is 0.5-1.2 parts by weight, the content of the sodium polyacrylate is 0.8-1.7 parts by weight, the content of the sodium bisulfite is 3-5 parts by weight, and the content of the barite is 250-300 parts by weight; the drilling fluid has favorable properties such as low viscosity and low HTHP water loss, etc.

First claim

The invention claimed is:

1. A deep-well polysulfonate drilling fluid, comprising: water, bentonite, sodium carbonate, a sulfomethylated phenolic resin, sulfonated lignite, a halide salt, a filtrate reducer, sodium polyacrylate, sodium bisulfite, and barite,
wherein, based on 100 parts by weight of water,
the content of the bentonite is 3.5-5 parts by weight,
the content of the sodium carbonate is 0.15-0.35 parts by weight,
the content of the sulfomethylated phenolic resin is 6-8 parts by weight,
the content of the sulfonated lignite is 6-8 parts by weight,
the content of the halide salt is 7.5-12 parts by weight,
the content of the filtrate reducer is 0.5-1.2 parts by weight,
the content of the sodium polyacrylate is 0.8-1.7 parts by weight,
the content of the sodium bisulfite is 3-5 parts by weight, and
the content of the barite is 250-300 parts by weight.

2. The deep-well polysulfonate drilling fluid according to claim 1 , wherein
the content of the bentonite is 4-4.8 parts by weight,
the content of the sodium carbonate is 0.2-0.24 parts by weight,
the content of the sulfomethylated phenolic resin is 6.5-7.8 parts by weight,
the content of the sulfonated lignite is 6.5-7.8 parts by weight,
the content of the halide salt is 9-10.8 parts by weight,
the content of the filtrate reducer is 0.75-0.9 parts by weight,
the content of the sodium polyacrylate is 1.2-1.44 parts by weight,
the content of the sodium bisulfite is 3.5-4.2 parts by weight, and
the content of the barite is 260-290 parts by weight.

3. The deep-well polysulfonate drilling fluid according to claim 1 , wherein the filtrate reducer is acrylamide/dimethyldiallyl ammonium chloride bipolymer, and/or acrylamide/dimethyldiallyl ammonium chloride/2-acrylamide-2-methyl propanesulfonic acid terpolymer; the halide salt is sodium chloride and/or potassium chloride; the barite is barite A having a grain size of 50 μm-70 μm and/or barite B having a grain size of 1 μm-1.2 μm.

4. The deep-well polysulfonate drilling fluid according to claim 3 , wherein the filtrate reducer is a composition of acrylamide/dimethyldiallyl ammonium chloride bipolymer and acrylamide/dimethyldiallyl ammonium chloride/2-acrylamide-2-methyl propanesulfonic acid terpolymer, wherein a weight ratio of the acrylamide/dimethyldiallyl ammonium chloride bipolymer to the acrylamide/dimethyldiallyl ammonium chloride/2-acrylamide-2-methyl propanesulfonic acid terpolymer is 0.6:1 to 0.8:1.

5. The deep-well polysulfonate drilling fluid according to claim 3 , wherein the halide salt is a composition of sodium chloride and potassium chloride, wherein a weight ratio of the sodium chloride to the potassium chloride is 0.6:1 to 0.96:1.

6. The deep-well polysulfonate drilling fluid according to claim 3 , wherein the barite is a composition of barite A and barite B, and the weight ratio of the barite A to the barite B is 1:1 to 4:1.

7. The deep-well polysulfonate drilling fluid according to claim 1 , wherein the pH of the deep-well polysulfonate drilling fluid is 8-9, and the density of the deep-well polysulfonate drilling fluid is 2.30 g/cm 3 -2.45 g/cm 3 .

8. A method for preparing a deep-well polysulfonate drilling fluid, comprising the following steps:
(1) mixing bentonite and sodium carbonate through a first mixing process and then treating the mixture by prehydration; (2) mixing the mixture obtained by prehydration in the step (1) with a filtrate reducer and sodium polyacrylate through a second mixing process, and then mixing the resultant mixture with a halide salt and sodium bisulfite through a third mixing process; (3/mixing the mixture obtained in the step (2) with sulfomethylated phenolic resin and sulfonated lignite through a fourth mixing process; wherein, based on 100 parts by weight of water, the dose of the bentonite is 3.5-5 parts by weight, the dose of the sodium carbonate is 0.15-0.35 parts by weight, the dose of the sulfomethylated phenolic resin is 6-8 parts by weight, the dose of the sulfonated lignite is 6-8 parts by weight, the dose of the halide salt is 7.5-12 parts by weight, the dose of the filtrate reducer is 0.5-1.2 parts by weight, the dose of the sodium polyacrylate is 0.8-1.7 parts by weight, the dose of the sodium bisulfite is 3-5 parts by weight, and the dose of the barite is 250-300 parts by weight.

9. The method according to claim 8 , wherein, based on 100 parts by weight of water,
the dose of the bentonite is 4-4.8 parts by weight,
the dose of the sodium carbonate is 0.2-0.24 parts by weight,
the dose t of the sulfomethylated phenolic resin is 6.5-7.8 parts by weight,
the dose t of the sulfonated lignite is 6.5-7.8 parts by weight,
the dose of the halide salt is 9-10.8 parts by weight,
the dose t of the filtrate reducer is 0.75-0.9 parts by weight,
the dose t of the sodium polyacrylate is 1.2-1.44 parts by weight,
the dose of the sodium bisulfite is 3.5-4.2 parts by weight, and the content of the barite is 260-290 parts by weight.

10. The method according to claim 8 , wherein the filtrate reducer is acrylamide/dimethyldiallyl ammonium chloride bipolymer, and/or acrylamide/dimethyldiallyl ammonium chloride/2-acrylamide-2-methyl propanesulfonic acid terpolymer; the halide salt is sodium chloride and/or potassium chloride; the barite is barite A having a grain size of 50 μm-70 μm and/or barite B having a grain size of 1 μm-1.2 μm.

11. The method according to claim 10 , wherein the filtrate reducer is a composition of acrylamide/dimethyldiallyl ammonium chloride bipolymer and acrylamide/dimethyldiallyl ammonium chloride/2-acrylamide-2-methyl propanesulfonic acid terpolymer, wherein a weight ratio of the acrylamide/dimethyldiallyl ammonium chloride bipolymer to the acrylamide/dimethyldiallyl ammonium chloride/2-acrylamide-2-methyl propanesulfonic acid terpolymer is 0.6:1 to 0.8:1.

12. The method according to claim 10 , wherein the halide salt is a composition of sodium chloride and potassium chloride, wherein a weight ratio of the sodium chloride to the potassium chloride is 0.6:1 to 0.96:1.

13. The method according to claim 10 , wherein the barite is a composition of barite A and barite B, wherein a weight ratio of the barite A to the barite B is 1:1 to 4:1.

14. The method according to claim 8 , wherein, in step (1) the conditions of the first mixing process include: temperature: 50-70° C., stirring rate: 550-650 r/min., and time: 30-45 min.;
the conditions of the prehydration treatment include: temperature: 50-70° C., stirring rate: 550-650 r/min., and time: 23-25 h;
wherein in step (2) the conditions of the second mixing process include: temperature: 60-70° C., stirring rate: 950-1,000 r/min., and time: 50-70 min.; and
the conditions of the third mixing process include: temperature: 60-70° C., stirring rate: 550-650 r/min., and time: 50-70 min.;
wherein, in step (3) the conditions of the fourth mixing process include: temperature: 60-70° C., stirring rate: 550-650 r/min., and time: 30-40 min.

15. The method according to claim 8 , further comprising stirring at a rate of 500-1,100 r/min. during at least one mixing process.

16. The method according to claim 15 , wherein the stirring rate is 550-1,000 r/min.

Assignees

• Univ Southwest Petroleum

Inventors

• Bai Yang
• Luo Pingya
• Lin Ling
• Liang Dachuan

Classifications

• C09K8/18 Primary

  characterised by the organic compounds · CPC title

• E21B21/062

  by mixing components · CPC title

• C09K8/16

  characterised by the inorganic compounds other than clay · CPC title

• C09K8/24 Primary

  Polymers · CPC title

• C09K8/5083

  obtained by reactions only involving carbon-to-carbon unsaturated bonds · CPC title