Drilling fluid composition and method of making the composition

1. A drilling fluid composition, comprising:

an aqueous base fluid;

0.01 to 5 wt. % of polyamine-functionalized activated carbon (AC-PAD);

0.1 to 10 wt. % of a shale material;

0.01 to 2 wt. % of a thickener;

0.1 to 10 wt. % of a fluid loss control additive;

0.01 to 5 wt. % of an adsorbent; and

1 to 20 wt. % of a borehole stabilizer;

wherein each wt. % based on a total weight of the drilling fluid composition;

wherein the AC-PAD is uniformly disposed on surfaces of the shale material; and

wherein the shale material has an average pore size of 5 to 400 nanometers (nm).

2. The drilling fluid composition of claim 1 , wherein the AC-PAD molecules are in the form of dendrimers having a plurality of at least one repeating unit selected from the group consisting of

and wherein n is any integer from 1 to 100 inclusive.

3. The drilling fluid composition of claim 1 , wherein each of the AC-PAD molecules comprises a carboxylic acid-functionalized activated carbon core and a plurality of polyamidoamine branch structures, and wherein at least one carboxyl group of the activated carbon core is covalently bonded to at least one amine group of at least one of the polyamidoamine branch structures.

4. The drilling fluid composition of claim 1 , wherein the shale material comprises at least one clay selected from the group consisting of sodium bentonite, calcium bentonite, potassium bentonite, sodium montmorillonite, and calcium montmorillonite.

5. The drilling fluid composition of claim 1 , wherein the shale material comprises 50 to 65 wt. % kaolinite, 15 to 35 wt. % quartz, 5 to 15 wt. % muscovite, 1 to 8 wt. % microcline, 0.1 to 3 wt. % goethite, 0.1 to 3 wt. % gibbsite, and 1 to 10 wt. % illite based on the total weight of the shale material.

6. The drilling fluid composition of claim 1 , wherein the aqueous base fluid comprises one or more selected from the group consisting of a foaming agent, a gelling agent, a pH control agent, a breaker, an oxidizing breaker, a gel stabilizer, a clay stabilizer, a corrosion inhibitor, a crosslinking agent, a scale inhibitor, a catalyst, a preservative, a biocide, and a thermal stabilizer.

7. The drilling fluid composition of claim 1 , wherein the thickener comprises at least one selected from the group consisting of xanthan gum, guar gum, corn starch, gelatin, and a cellulosic thickener.

8. The drilling fluid composition of claim 1 , wherein the fluid loss control additive comprises at least one selected from the group consisting of lignite, cellulose, and hemicellulose.

9. The drilling fluid composition of claim 1 , wherein the adsorbent comprises poly aluminum chloride having a formula [Al 2 (OH) n Cl 6-n ] m , wherein 1≤n≤5, and 0<m≤10.

10. The drilling fluid composition of claim 1 , wherein the borehole stabilizer comprises at least one selected from the group consisting of sodium sulfite (Na 2 SO 3 ) and potassium chloride (KCl).

11. The drilling fluid composition of claim 1 , having a pH in a range of 8 to 10.

12. The drilling fluid composition of claim 1 , having a shale material expansion rate of 1 to 15%, and a shale dispersion recovery rate of 75 to 95%, each based on an initial weight of the shale material, as determined by American Petroleum Institute (API) standard procedures (API, 2019).

13. The drilling fluid composition of claim 1 , having a reduction in swelling of at least 10% compared to a swelling value obtained from a drilling fluid composition without the AC-PAD, as determined by a linear swell meter.

14. A method of making the drilling fluid composition of claim 1 , comprising:

dispersing particles of the shale material in the aqueous base fluid to form a suspension;

wherein the shale material has an average particle size in a range of 1500 to 4000 micrometers (μm);

mixing the AC-PAD, the thickener, the fluid loss control additive, the adsorbent, the borehole stabilizer, and the suspension to form the drilling fluid composition;

wherein the AC-PAD is present in the drilling fluid composition at a concentration of 0.1 to 2 wt. % based on a total weight of the drilling fluid composition.

15. A method of making the drilling fluid composition of claim 14 , further comprising:

preparing the AC-PAD by:

treating activated carbon (AC) from palm fibers in the presence of an acid solution comprising nitric acid to form carboxylic acid-functionalized AC;

mixing the carboxylic acid-functionalized AC, an alcohol, and a polyamine to form a reaction mixture;

mixing the reaction mixture with an alkyl acrylate to form a crude mixture comprising AC-PAD molecules in the form of dendrimers; and

separating the AC-PAD from the crude mixture, washing, and drying to form the AC-PAD.

16. The method of claim 15 , wherein the alcohol comprises at least one selected from the group consisting of methanol, ethanol, n-propanol, 2-propanol, 1-butanol, and 2-butanol, and wherein the alkyl acrylate has a formula (I)

wherein R 1 , and R 2 are each independently selected from the group consisting of hydrogen, an optionally substituted alkyl, and an optionally substituted cycloalkyl.

17. The method of claim 15 , wherein the polyamine comprises at least one of ethylenediamine, hexamethylenediamine, N1,N1-dimethvlethane-1,2-diamine, N1,N1-dimethylpropan-1,3-diamine, N1,N1-diethylethane-1,2-diamine, N1,N1-diethylpropane-1,3-diamine, spermidine, 1,1,1-tris(aminomethyl)ethane, tris(2-aminoethyl)amine, spermine, TEPA, DETA, TETA, AEEA, PEHA, HEHA, dipropylene triamine, tripropylene tetramine, tetrapropylene pentamine, pentapropylene hexamine, hexapropylene heptamine, dibutylene triamine, tributylene tetramine, tetrabutylene pentamine, pentabutylene hexamine, hexabutylene and heptamine.

18. A method of drilling a subterranean geological formation, the method comprising:

drilling the subterranean geological formation to form a wellbore therein; and

circulating the drilling fluid composition of claim 1 into the wellbore during the drilling.

19. The method of claim 18 , wherein the subterranean geological formation comprises at least one selected from the group consisting of a shale formation, a clay formation, a tar sands formation, a coal formation, and a conventional hydrocarbon formation.

20. The method of claim 18 , wherein the wellbore has a temperature of 20 to 300° C., and a pressure of 50 to 5500 pound-force per square inch (psi).