Compressible carbonaceous particulate material and method of making same
View Patent ↗A carbonaceous particulate material is provided that is characterized by having a reversible volumetric expansion/contraction in fluid media (“V R ”) of greater than or equal to (≧)3% between 4,000 psi and 10,000 psi. The porous carbonaceous particulate material of the present disclosure is also characterized by having a true density, (“P T ”), of 1.2 g/cc≦P T ≦2.0 g/cc, when milled to −200 mesh and has a d 50 particle size distribution of about 15 μm. This is the consequence of the instant material exhibiting a high level of closed porosity with very small pores, in contrast with prior art materials that would have a wider range pore sizes for the closed pores.
1. A porous carbon material characterized by having a reversible volumetric expansion/contraction in a fluid media, V R , of ≧3% between 4,000 psi and 10,000 psi.
2. The porous carbon of claim 1 wherein the fluid media is selected from the group consisting of water, mercury and diesel fuel.
3. The porous carbon material of claim 1 further characterized by having a true density, P T , of 1.2 g/cc≦P T ≦2.0 g/cc when milled to −200 mesh and to a d 50 particle size of about 15 μm.
4. The porous carbon material of claim 1 further characterized by having a d 50 mean particle size of from 5 um to 8 mesh (2.38 mm).
5. The porous carbon material of claim 1 further characterized by having a degree of graphitization of ≦60%.
6. The porous carbon material of claim 1 further characterized by having a sulfur content of less than or equal to 8.0%.
7. A porous carbon material characterized by having a reversible volumetric expansion/contraction in a fluid media, V R , of ≧3% between 4,000 psi and 10,000 psi; a d 50 particle size of 437 um and a true density P T of 1.49 g/cc when unmilled, and a d 50 particle size of 15.8 um and a true density P T of 1.67 g/cc after milling.
8. A method for mitigating annular pressure build up in a borehole having a casing and an annulus comprising adding a fluid including a porous carbon material in accordance with claim 1 to the annulus between the casing and the borehole.