Hydrocarbon swelling particles for wellbore cementing

1. An at least partially crosslinked polymer comprising:

at least one vinyl aromatic monomer selected from the group consisting of para-tertbutylstyrene, 4-tert-butoxystyrene, 4-benzhydrylstyrene, 9-vinylanthracene, and 4-vinylbiphenyl; and

at least one (meth)acrylic monomer selected from the group consisting of isobutyl methacrylate, tert-butyl-methacrylate, and 2-ethylhexyl acrylate;

wherein the at least one (meth)acrylic monomer comprises tert-butyl-methacrylate in an amount of at least 30 mol % of the polymer.

2. A wellbore cementing composition comprising:

cement powder; and

hydrocarbon swelling particles comprising the at least partially crosslinked polymer of claim 1 .

3. A method for producing a cementitious wellbore sheath comprising:

pumping a slurry into a wellbore;

wherein the slurry comprises:

cement;

water; and

hydrocarbon swelling particles comprising the at least partially crosslinked polymer of claim 1 .

4. The method of claim 3 , wherein the slurry further comprises:

a polycarboxylate dispersant.

5. The method of claim 3 , wherein the particles have diameters within a range of about 20 μm to about 1,000 μm.

6. The method of claim 3 , wherein the particles have a 050 in a range of about 50 μm to about 300 μm.

7. An at least partially crosslinked polymer comprising:

at least one vinyl aromatic monomer selected from the group consisting of para-tertbutylstyrene, 4-tert-butoxystyrene, 4-benzhydrylstyrene, 9-vinylanthracene, and 4-vinylbiphenyl; and

at least one (meth)acrylic monomer selected from the group consisting of isobutyl methacrylate, tert-butyl-methacrylate, and 2-ethylhexyl acrylate;

wherein the at least one vinyl aromatic monomer comprises para-tertbutylstyrene in an amount of at least 50 mol % of the polymer; wherein the at least one (meth)acrylic monomer comprises isobutyl methacrylate or tert-butyl-methacrylate in an amount of at least 30 mol % of the polymer; and wherein the polymer further comprises 2-ethylhexyl acrylate.

8. The at least partially crosslinked polymer of claim 7 , wherein the 2-ethylhexl acrylate is in an amount of 5 mol % to 20 mol % of the polymer.

9. A wellbore cementing composition comprising

cement powder; and

hydrocarbon swelling particles comprising the at least partially crosslinked polymer of claim 7 .

10. A wellbore cementing composition comprising:

cement powder; and

hydrocarbon swelling particles comprising the at least partially crosslinked polymer of claim 8 .

11. A method for producing a cementitious wellbore sheath comprising:

pumping a slurry into a wellbore;

wherein the slurry comprises:

cement;

water; and

hydrocarbon swelling particles comprising the at least partially crosslinked polymer of claim 7 .

12. A method for producing a cementitious wellbore sheath comprising:

pumping a slurry into a wellbore;

wherein the slurry comprises:

cement;

water; and

hydrocarbon swelling particles comprising the at least partially crosslinked polymer of claim 8 .