Increasing buoyancy of well treating materials
View Patent ↗A composite proppant having an increased buoyancy comprising a proppant substrate such as a porous ceramic or a silica sand coated with a material of a lesser actual density than the apparent density of the proppant substrate to increase the buoyancy of the composite proppant.
1. A method for treating a subterranean formation comprising introducing into fractures in the formation particles comprising a composite proppant, said composite proppant comprising a proppant substrate capable of withstanding a closure pressure of at least about 5,000 psi and having an adhered coating of a particulate material with an actual density less than an apparent density of the proppant substrate, wherein the particulate material has an actual density of less than 0.5 g/cc, and wherein at least 90 wt % of the particulate material has a particle size distribution ranging from 75 μm to 150 μm.
2. The method of claim 1 , wherein the proppant substrate is selected from the group consisting of bauxite, silica sand and porous ceramic, optionally coated with a resin.
3. The method of claim 1 , wherein the adhered coating of particulate material comprises a particulate cork.
4. The method of claim 3 , wherein the particulate cork comprises 2% to 3% by weight of the composite proppant.
5. The method of claim 1 , wherein the particulate material is adhered to the proppant substrate using a hot melt adhesive.
6. The method of claim 1 , wherein the particulate material is adhered to the proppant substrate using a novolac resin crosslinked with hexamine.
7. The method of claim 5 , wherein the hot melt adhesive includes a thermoplastic resin.
8. The method of claim 1 , wherein the adhered coating of particulate material comprises 0.1% to 20% by weight of the composite proppant.
9. A particulate composite proppant, comprising:
a proppant substrate capable of withstanding a closure pressure of at least about 5,000 psi; and
an adhered coating of a particulate material with an actual density less than an apparent density of the proppant substrate, wherein the particulate material has an actual density of less than 0.5 g/cc, and wherein at least 90 wt % of the particulate material has a particle size distribution ranging from 75 μm to 150 μm.
10. The particulate composite proppant of claim 9 further comprising an adhesive adhering the particulate material to the proppant substrate.
11. The particulate composite proppant of claim 10 , wherein the adhesive includes a thermoplastic resin.
12. The particulate composite proppant of claim 10 , wherein the adhesive includes a wax powder.
13. The particulate composite proppant of claim 10 , wherein the adhesive includes a thermosetting resin.
14. The particulate composite proppant of claim 9 , wherein the adhered coating of particulate material comprises a particulate cork.
15. The particulate composite proppant of claim 14 , wherein the particulate cork comprises 2% to 3% by weight of the particulate composite proppant.
16. The particulate composite proppant of claim 9 , wherein the proppant substrate comprises at least one of a porous ceramic, silica sand, bauxite and hollow glass, optionally having a resin coating.
17. The particulate composite proppant of claim 15 , wherein the proppant substrate comprises a particulate silica sand.
18. The particulate composite proppant of claim 10 , wherein the particulate material comprises 0.1% to 20% of the composite proppant by weight.
19. The particulate composite proppant of claim 9 , wherein the proppant substrate is capable of withstanding a closure pressure of at least about 7,500 psi.
20. The particulate composite proppant of claim 9 , wherein the particulate material is adhered to the proppant substrate with an adhesive comprising a hot melt adhesive.