Sulphur based proppants and process therefor

Abstract

A proppant for enhancing the recovery of petroleum from rock formations comprises pellets of sulphur and a binding and strengthening additive, preferably comprising cement. A process for manufacturing the proppant comprises first melting sulphur to form a liquid and forming a mixture of the liquid sulphur with cement powder. The mixture is then cooled and pelletized to form pellets of a sulphur and cement composite. The pellets are then dried and sorted by size.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:  
     
         1 . A proppant for enhancing recovery of petroleum from rock formations comprising pellets of a mixture of sulphur and a first binding and strengthening additive.  
     
     
         2 . The process of  claim 1  wherein the first binding and strengthening additive is a cement powder.  
     
     
         3 . The process of  claim 1  wherein the sulphur is extracted from petroleum during petroleum refining processes.  
     
     
         4 . The proppant of  claim 1  wherein the weight ratio of said sulphur and said additive is 3:1.  
     
     
         5 . The proppant of  claim 1  wherein the pellets include a surface coating.  
     
     
         6 . The proppant of  claim 5  wherein the surface coating comprises a smooth, durable material.  
     
     
         7 . The proppant of  claim 6  wherein the surface coating is comprised of a resin  
     
     
         8 . The proppant of  claim 6  wherein the surface coating comprises an epoxy.  
     
     
         9 . The proppant of  claim 1  further including a second binding additive.  
     
     
         10 . The proppant of  claim 9  wherein said second binding additive is silicone.  
     
     
         11 . A process for forming a proppant for enhancing recovery of petroleum from rock formations, the proppant comprising pellets of a mixture of sulphur and a binding and strengthening additive, the process comprising: 
 heating said sulphur to form a liquid;    forming a mixture of liquid sulphur and the binding and strengthening additive;    heating the mixture to maintain said mixture in a liquid state;    cooling and pelletizing the mixture;    retrieving and drying said pellets.    
     
     
         12 . The process of  claim 11  wherein said mixture is heated to a temperature at or above the melting point of the sulphur component.  
     
     
         13 . The process of  claim 12  wherein said mixture is heated to about 118° C.  
     
     
         14 . The process of  claim 11  wherein said pelletizing step includes dripping said heated liquid mixture into a cooling bath to solidify said pellets.  
     
     
         15 . The process of  claim 14  wherein said cooling bath comprises a chamber cooled with swirling cold water.  
     
     
         16 . The process of  claim 11  further including sorting said pellets by size.  
     
     
         17 . The process of  claim 11  further including coating said pellets with a surface coating.  
     
     
         18 . The process of  claim 17  wherein said coating comprises a resin material.  
     
     
         19 . The process of  claim 11  further comprising extracting said sulphur from petroleum in a petroleum refining process.