Dewatering of drilling mud using a filter press

Abstract

A method of separating a mixture of liquid and insoluble solids in a filter press may comprise: diluting the mixture; adding a flocculating agent to the diluted mixture and stirring to form a chemically processed mixture; pumping the chemically processed mixture into a chamber between two filter plates in the filter press to form a filter cake, wherein the chamber is lined by filter cloths, and wherein, during the pumping, filtrate is forced through the filter cloths and out of the chamber; heating the filter cake in the chamber, wherein, during the heating, filtrate is forced through the filter cloths and out of the chamber; and releasing dried filter cake from the chamber. During the heating, the chamber may be vacuum pumped to facilitate removal of water vapor. Furthermore, before the diluting, additional solids may be added to the mixture. The method may be used to dewater drilling mud, and mixtures of drilling mud with drill cuttings. A system for dewatering a mixture of drilling mud and drill cuttings may comprise: a mixing vessel for mixing together the drilling mud and drill cuttings to form the mixture; a filter press for dewatering the chemically processed mixture; a pump for pumping the mixture from the mixing vessel into the filter press; and a heater for heating the mixture in the filter press.

1 - 32 . (canceled) 
     
     
         33 . A method of separating a mixture of liquid and insoluble solids in a filter press, said method comprising:
 providing said mixture;   adding additional solids to said mixture to form a solids-enriched mixture;   pumping said solids-enriched mixture into a chamber between two filter plates in said filter press to form a filter cake, wherein said chamber is lined by filter cloths, and wherein, during said pumping, filtrate is forced through said filter cloths and out of said chamber;   heating said filter cake in said chamber, wherein, during said heating, filtrate is forced through said filter cloths and out of said chamber; and   releasing dried filter cake from said chamber.   
     
     
         34 . The method as in  claim 33 , wherein said mixture is drilling mud and said additional solids is drill cuttings. 
     
     
         35 . A filter press system for separating a mixture of liquid and insoluble solids, said filter press system comprising:
 a frame;   a plurality of filter plates configured to form a stack of parallel plates, each of said plurality of filter plates being movably attached to said frame, said plurality of filter plates further being configured to form a multiplicity of chambers, each of said multiplicity of chambers being formed by adjacent filter plates of said plurality of filter plates, each of said multiplicity of chambers being lined by filter cloths, wherein said plurality of filter plates, said multiplicity of chambers and said filter cloths are configured to allow filtrate to escape from said chambers while retaining solids from said mixture to form a filter cake;   a mixing vessel configured to mix additional solids into said mixture to form a solids-enriched mixture;   a pump for pumping said solids-enriched mixture from said mixing vessel to said tank; and   a heater for heating filter cake in said multiplicity of chambers.   
     
     
         36 . The system as in  claim 35 , further comprising a vacuum pump connected to said multiplicity of chambers. 
     
     
         37 . The system as in  claim 35 , wherein said heater is a radio frequency heater. 
     
     
         38 . The system as in  claim 37 , wherein said radio frequency heater comprises parallel electrode plates attached to said frame and electrically coupled to a radio frequency generator, said parallel electrode plates being configured with the planes of said parallel electrode plates roughly orthogonally to the planes of each of said plurality of filter plates, and in close proximity to the outer surface and on either side of said plurality of filter plates. 
     
     
         39 . The system as in  claim 35 , wherein said heater is a boiler, said boiler being connected to said plurality of filter plates by conduits for delivering steam to cavities within said plurality of filter plates. 
     
     
         40 . The system as in  claim 35 , wherein said plurality of filter plates are made of plastics. 
     
     
         41 . The system as in  claim 40 , wherein each of said plurality of filter plates includes an envelope, said envelope being inflatable by a fluid. 
     
     
         42 . The system as in  claim 41 , wherein said fluid is steam. 
     
     
         43 . The system as in  claim 41 , wherein said fluid is compressed air. 
     
     
         44 . The system as in  claim 35 , wherein said pump is a low shear pump. 
     
     
         45 . The system as in  claim 35 , wherein said mixing vessel is a low shear mixing vessel. 
     
     
         46 . The system as in  claim 37 , wherein said radio frequency heater is a microwave heater. 
     
     
         47 . The system as in  claim 46 , wherein said microwave heater produces irradiation at a frequency between 300 and 3000 MHz. 
     
     
         48 . The system as in  claim 46 , wherein said microwave heater produces irradiation at a frequency between 1 and 100 MHz. 
     
     
         49 . The system as in  claim 35 , wherein said plurality of said filter plates is N filter plates and said multiplicity of said chambers is M chambers, M is equal to N−1, and N and M are integers. 
     
     
         50 . The system as in  claim 35 , further comprising a kiln configured for firing filter cake released from said chambers. 
     
     
         51 . The system as in  claim 35 , wherein said mixture is drilling mud and said additional solids is drill cuttings. 
     
     
         52 . The system as in  claim 37 , wherein said radio frequency heater comprises at least one pair of parallel opposed electrode plates configured with the planes of said parallel opposed electrode plates roughly orthogonal to the planes of each of said multiplicity of filter plates, with each of said parallel opposed electrode plates for each of said at least one pairs being on opposite sides of, external to, and in close proximity to said plurality of filter plates.