Vapor displacement method for hydrocarbon removal and recovery from drill cuttings

Abstract

A method comprises solubilizing hydrocarbons in drill cuttings with a liquid solvent. The method further comprises displacing the miscible fluid portion from by pressurized vapor. The method can utilize the pressurized vapor to heat the miscible fluid. The method can utilize the miscible fluid to cool the solvent.

What is claimed is: 
     
         1 . A method comprising:
 solubilizing hydrocarbons from drill cuttings with a liquid solvent to form a miscible fluid; and   displacing the miscible fluid with vapor.   
     
     
         2 . The method of  claim 1 , further comprising conveying the drill cuttings into a vessel, and wherein the displacing of the miscible fluid comprises displacing the miscible fluid from the vessel with the vapor. 
     
     
         3 . The method of  claim 1 , wherein the liquid solvent is liquid carbon dioxide. 
     
     
         4 . The method of  claim 2 , wherein the displacing the miscible fluid with vapor comprises providing the vapor to the vessel and displacing the miscible fluid out of a bottom of the vessel. 
     
     
         5 . The method of  claim 1 , wherein the vapor is vapor carbon dioxide and the liquid solvent is liquid carbon dioxide. 
     
     
         6 . The method of  claim 1 , further comprising displacing the miscible fluid with an additional amount of the liquid solvent. 
     
     
         7 . The method of  claim 1 , wherein the vapor is nitrogen, carbon dioxide, air or inert gas. 
     
     
         8 . The method of  claim 1 , further comprising heating the miscible fluid at an economizer with the vapor. 
     
     
         9 . The method of  claim 5 , further comprising heating the miscible fluid at an economizer with the vapor carbon dioxide. 
     
     
         10 . The method of  claim 1 , wherein the solubilizing and the displacing are repeated if the amount of the hydrocarbons remaining on the drill cuttings is greater than one-percent. 
     
     
         11 . The method of  claim 1 , further comprising vaporizing the miscible fluid to separate the hydrocarbons from the solvent in a vapor or gas state. 
     
     
         12 . The method of  claim 8 , further comprising:
 decreasing the pressure prior to the heating the miscible fluid;   vaporizing the miscible fluid to form vapor carbon dioxide; and   separating the hydrocarbons from the vapor carbon dioxide.   
     
     
         13 . A method comprising:
 conveying drill cuttings into a vessel;   solubilizing hydrocarbons from drill cuttings with solvent in a liquid state to form a miscible fluid;   displacing the miscible fluid from the vessel; and   heating the miscible fluid at an economizer with the solvent in a vapor or gas state.   
     
     
         14 . The method of  claim 13 , wherein the displacing the miscible fluid from the vessel comprises providing the solvent in the vapor or gas state to the vessel to force the miscible fluid out of the vessel. 
     
     
         15 . The method of  claim 13 , further comprising cooling the solvent in the vapor or gas state with the miscible fluid at the economizer. 
     
     
         16 . The method of  claim 14 , wherein the displacing the miscible fluid comprises displacing substantially all of the miscible fluid and further comprising removing the solvent in the vapor or gas state prior to removing the cuttings from the vessel. 
     
     
         17 . The method of  claim 15 , wherein the economizer vaporizes the miscible fluid, and further comprising separating the hydrocarbons from the solvent in a vapor or gas state. 
     
     
         18 . A method comprising:
 conveying drill cuttings into a vessel, the drill cuttings having hydrocarbons in excess of one-percent by mass;   providing liquid carbon dioxide to the vessel to solubilize the hydrocarbons;   agitating the drill cuttings and liquid carbon dioxide in the vessel to form a miscible fluid;   displacing the miscible fluid from the vessel with vapor carbon dioxide.   
     
     
         19 . The method of  claim 18 , further comprising heating the miscible fluid at an economizer with the vapor carbon dioxide to vaporize the miscible fluid such that the hydrocarbons are separable from the vapor carbon dioxide. 
     
     
         20 . The method of  claim 18 , further comprising reducing an amount of the hydrocarbons in the drill cuttings to the one-percent or less prior to the displacing the miscible fluid from the vessel with the vapor carbon dioxide.