Methods of separating drilling cuttings and gas using a liquid seal

Abstract

A gas separator, gas separation system, and method for separating gas from drilling cuttings by actively maintaining a liquid seal of liquid in a lower portion of a separation vessel by controlling an introduced amount of the liquid admitted to the separation vessel as a removed amount of the liquid is removed from the separation vessel and by promoting agitation of the drilling cuttings in the liquid in an agitation chamber within the lower portion of the separation vessel to aid removal of the drilling cuttings along with the removed amount of the liquid.

What is claimed is: 
     
         1 . A method for separating gas from drilling cuttings, the method comprising:
 introducing a drilling fluid into a separation vessel, the drilling fluid comprising the gas and the drilling cuttings;   introducing a liquid into the separation vessel;   actively maintaining a liquid seal of the liquid in a lower portion of the separation vessel by controlling an introduced amount of the liquid admitted to the separation vessel as a removed amount of the liquid is removed from the separation vessel;   agitating the drilling cuttings in the liquid within the lower portion of the separation vessel to aid separating gas from the drilling cuttings; and   removing the drilling cuttings along with the removed amount of the liquid from the separation vessel.   
     
     
         2 . The method of  claim 1 , further comprising removing the gas from the separation vessel via a gas outlet. 
     
     
         3 . The method of  claim 1 , wherein the removing of the drilling cuttings along with the removed amount of the liquid from the separation vessel is via a bottom discharge outlet in the lower portion of the separation vessel. 
     
     
         4 . The method of  claim 1 , further comprising applying a fluid spray within a portion of the separation vessel above the liquid seal for promoting movement of the drilling cuttings downward but allowing the flow of the gas upward. 
     
     
         5 . The method of  claim 1 , wherein the agitating comprises introducing the liquid under pressure via at least one mixing nozzle directed within the lower portion of the separation vessel. 
     
     
         6 . The method of  claim 1 , wherein the actively maintaining the liquid seal comprises maintaining a surface of the liquid above an opening at an end of a discharge tube, wherein the removed amount of the liquid is removed via the discharge tube. 
     
     
         7 . The method of  claim 1 , further comprising urging the drilling cuttings toward a central axis of the lower portion of the separation vessel using a centering baffle within the separation vessel. 
     
     
         8 . The method of  claim 1 , further comprising providing a tortuous path past a baffle within the separation vessel to separate gas from another substance selected from a group consisting of drilling cuttings, the liquid, and foam. 
     
     
         9 . A method for processing a drilling fluid to separate gas from drilling cuttings, the method comprising:
 introducing the drilling fluid into a separation vessel, the drilling fluid comprising the gas and the drilling cuttings;   introducing a liquid into the interior space of the separation vessel to maintain a liquid seal level within the interior space of the separation vessel and maintaining the liquid seal level using a circulation pump;   discharging the gas from the interior space of the separation vessel; and   discharging the drilling cuttings from the interior space of the separation vessel.   
     
     
         10 . The method of  claim 9 , wherein the separation vessel has a body, the body having a top wall, a bottom wall, a sidewall, an upper portion and a lower portion and the body forming a closed structure defining an interior space of the separation vessel and the lower portion comprising an agitation chamber within the interior space. 
     
     
         11 . The method of  claim 9 , further comprising wetting particulates borne by the gas with the liquid as the gas rises to the gas outlet after the separation. 
     
     
         12 . The method of  claim 9 , further comprising injecting a jet of liquid into the lower portion of the interior space of the separation vessel to agitate the drilling cuttings with a swirling action. 
     
     
         13 . The method of  claim 10 , further comprising injecting a jet of liquid into the lower portion of the interior space of the separation vessel to agitate the drilling cuttings with a swirling action within the agitation chamber, wherein the agitation chamber is configured to promote agitation of the drilling cuttings in the liquid within the agitation chamber to aid removal of the drilling cuttings along with a removed amount of the liquid thereby separating the drilling cuttings from the gas. 
     
     
         14 . The method of  claim 9 , further comprising detecting liquid levels within the interior space of the separation vessel using at least one fluid level sensor configured to detect the liquid levels. 
     
     
         15 . The method of  claim 9 , further comprising controlling an discharge pump and a circulation pump to actively maintain the liquid seal of the liquid in a lower portion of the interior space of the separation vessel by controlling an introduced amount of the liquid admitted to the interior space of the separation vessel as the removed amount of the liquid is removed from the interior space of the separation vessel. 
     
     
         16 . The method of  claim 12 , further comprising adjusting the flow rate and swirl pattern of the jet of liquid into the lower portion of the interior space of the separation vessel. 
     
     
         17 . The method of  claim 9 , wherein the discharging of gas is via a gas outlet in the upper portion interior space of the separation vessel. 
     
     
         18 . The method of  claim 9 , further comprising charging the separation vessel with the liquid prior to introducing drilling fluid into a separation vessel.