Apparatus and system for processing solids in subsea drilling or excavation

An apparatus for processing solids within a body of water in association with a riser and drill string, the apparatus comprising:

• a solids processing apparatus having a central cavity, the central cavity of the solids processing unit being positioned in vertical alignment with the riser and drill string, the solids processing apparatus being adapted for receiving solids within the central cavity and reducing the particle size of the solids to form processed solids, wherein the solids processing apparatus further comprises:
• (a) a load bearing inner sleeve surrounding the central cavity, the inner sleeve being configured for receiving and transferring substantial riser/drill string load forces,
• (b) a housing shell positioned circumferentially outside of the inner sleeve,
• (c) wherein a peripheral annulus region is provided between the inner sleeve and the housing shell,
• (d) a first cutter assembly positioned in the peripheral annulus region, and
• (e) an intake aperture in communication with the central cavity, the intake aperture being adapted for transferring drilled solids to the central cavity of the solids processing apparatus.

A method of processing solids within a body of water, the body of water having a water surface and a mudline surface, wherein a riser extends below the water surface, the riser being filled with a first fluid having a first density, with a wellbore extending below the mudline surface, the wellbore being filled with a second fluid of a second density, wherein the second density is greater than the first density, a fluid separation mechanism being connected to the riser and in fluid communication to the wellbore, the fluid separation mechanism being adapted for maintaining a differential density between the first and second fluids, the method comprising the steps of:

• (a) providing a solids processing apparatus having a central cavity, the solids processing apparatus being positioned in vertical alignment- with the riser, further wherein the solids processing apparatus is positioned to accommodate the extension of a tool downward through the riser and into the central cavity of the solids processing apparatus,
• (b) transporting solids from the wellbore to the interior space of the solids processing apparatus,
• (c) reducing the size of the solids to produce processed solids,
• (d) expelling processed solids from the solids processing apparatus,
• (e) providing a mud lift pump,
• (f) transferring the processed solids to the mud lift pump,
• (g) pumping the processed solids to the water surface, and
• (h) extending a wash tool through the riser into the central cavity of the solids processing apparatus, and
• (i) washing solids from the interior of the solids processing apparatus.