System and process for hydrocyclone separation of particulate solids and at least one liquid phase from a multiphase liquid mixture

A process for separating a production stream from an oil well comprising a heavier phase component, a lighter phase component and a particulate solids component into a plurality of separately classifiable streams, wherein the process comprises the steps of:

• (a) separating at least a portion of the production stream into at least a lighter phase liquid stream and a heavier phase liquid stream;
• (b) cyclonically separating at least a portion of the heavier phase liquid stream into a particulate solids stream and a liquid mixture stream;
• (c) cyclonically separating at least a portion of the liquid mixture stream from step (b) into an overflow and an underflow wherein the overflow comprises a relatively greater concentration of lighter phase liquid component compared to such concentration in the heavier phase liquid stream produced in step (a);
• (d) elevating the pressure of at least a portion of the underflow produced in step (b) to a higher pressure;
• and
• (e) cyclonically separating particulate solids from at least a portion of the higher pressure underflow from step (c);
• and
• (f) separating a substantially particulate solids free mixture resulting from step (e) into lighter and heavier phase liquid portions;
• the process excluding said particulate solids stream from said step (b) being further separated in equipment provided for cyclonic separation in steps (c) or (e).

A system for separating a multiphase liquid mixture comprising a heavy phase liquid component, a lighter phase liquid component and a particulate solids component into a plurality of separately classifiable streams, wherein the apparatus comprises:

• first separation means for cyclonically separating the mixture into a first portion and a second portion wherein the first portion comprises a relatively greater concentration of particulate solids compared to the multiphase liquid mixture;
• second separation means for cyclonically separating the second portion from said first separation means into an overflow and an underflow wherein the overflow comprises a greater proportion of lighter phase liquid to heavier phase liquid than the underflow;
• means for elevating the pressure of the underflow;
• and
• third separation means for cyclonically separating a substantial portion of any remaining particulate solids from the elevated pressure underflow;
• and
• wherein said system does not include means for directing said first portion from said first separation means to either of said second or third separation means.