Drill Cuttings Transfer System and Related Methods

Abstract

A system for handling drill cuttings conveys cuttings into bulk tanks via a conduit. The bulk tanks have a lower portion that converges to an elongated opening. A conveyance member positioned at the elongated opening forces the cuttings out of a discharge port at the bottom of the bulk tank. Once suitable conveyance member is a screw-type conveyor coupled to a motor that applies a motive force to the cuttings. The bulk tank lower portion can be formed as a wedge or trough that generally conforms to the configuration of the conveyance member. The bulk tanks hold the cuttings until it can be discharged via the discharge port to a transport vessel for processing or disposal. For offshore operations, the system includes a separation unit on the rig that forms the cuttings from fluid returning from the wellbore and a cuttings flow unit that conveys the cuttings from the separation unit to the bulk tanks.

1 . A system for handling a return fluid formed of drilling fluid and entrained cuttings recovered while drilling a wellbore in an earthen formation, comprising:
 (a) a separation unit at least partially separating the drilling fluid from the return fluid, a slurry of cuttings thereby being formed;   (b) a cuttings flow unit receiving the cuttings from the separation unit, the cutting flow unit conveying the cuttings through a conduit coupled thereto;   (c) at least one tank coupled to the conduit, the tank having a lower portion converging to an elongated opening; and   (d) a conveyance member positioned adjacent to the elongated opening receiving the cuttings from the lower portion and flowing the cuttings out of the at least one bulk tank.   
   
   
       2 . The system of  claim 1 , further comprising a flow device receiving the flow of cuttings from the conveyance member and conveying the cuttings to a selected location. 
   
   
       3 . The system of  claim 2 , further comprising a gas source providing a pressurized gas to the at least one tank to at least partially offset a pressure increase associated with operation of the cuttings flow device. 
   
   
       4 . The system of  claim 1 , further comprising a gas source providing a gas to the at least one tank to fluidize at least a portion of the cuttings in the at least one tank. 
   
   
       5 . The system of  claim 1 , wherein the lower portion is wedge shaped and wherein the conveyance member includes an auger longitudinally aligned with the elongated opening. 
   
   
       6 . The system of  claim 1 , wherein the at least one tank includes a cylindrical upper portion, the cuttings flowing from the upper portion to the lower portion. 
   
   
       7 . The system of  claim 1  wherein the conveyance member operates in a first mode to flow the cuttings and a second mode to mix the cuttings. 
   
   
       8 . A method for handling a return fluid formed of drilling fluid and entrained cuttings recovered while drilling a wellbore in an earthen formation, comprising:
 (a) separating the drilling fluid from the return fluid to form a slurry of cuttings with a separation unit;   (b) conveying the cuttings through a conduit coupled to the separation unit using a cuttings flow unit;   (c) receiving the cuttings into at least one tank coupled to the conduit, the bulk tank having a lower portion converging to an elongated opening; and   (d) flowing the cuttings out of the at least one tank using a conveyance member positioned adjacent to the elongated opening.   
   
   
       9 . The method of  claim 8 , further comprising conveying the cuttings to a selected location using a flow device that receives the flow of cuttings from the conveyance member. 
   
   
       10 . The method of  claim 9 , further at least partially offsetting a pressure increase associated with operation of the flow device using a gas source that provides a pressurized gas to the at least one tank. 
   
   
       11 . The method of  claim 8 , further comprising fluidizing at least a portion of the cuttings in the at least one tank using a gas source that provides a gas to the at least one tank. 
   
   
       12 . The method of  claim 8 , wherein the lower portion is wedge shaped and wherein the conveyance member includes an auger longitudinally aligned with the elongated opening. 
   
   
       13 . The method of  claim 8 , wherein the at least one tank includes a cylindrical upper portion, the cuttings flowing from the cylindrical upper portion to the lower portion. 
   
   
       14 . The method of  claim 8  further comprising operating the conveyance member in a first mode to flow the cuttings and a second mode to mix the cuttings. 
   
   
       15 . A system for handling cuttings separated from a return fluid formed of drilling fluid and entrained cuttings, comprising:
 (a) a tank for receiving the cuttings, the tank having a cylindrical upper portion and a wedge shaped lower portion converging to an elongated opening; and   (b) a conveyance member positioned adjacent to the elongated opening receiving the cuttings from the wedge shaped lower portion and flowing the cuttings out of the tank.   
   
   
       16 . The system of  claim 15 , further comprising a flow device receiving the flow of cuttings from the conveyance member and conveying the cuttings to a selected location. 
   
   
       17 . The system of  claim 16 , further comprising a gas source providing a pressurized gas to the tank to at least partially offset a pressure increase associated with operation of the cuttings flow device. 
   
   
       18 . The system of  claim 15 , further comprising a gas source providing a gas to the tank to fluidize at least a portion of the cuttings in the tank. 
   
   
       19 . The system of  claim 15  wherein the conveyance member operates in a first mode to flow the cuttings and a second mode to mix the cuttings. 
   
   
       20 . The system of  claim 15  wherein the lower portion is defined by a first set of walls and a second set of walls, each of the walls of the first and second set of walls having an angle selected to cause mass flow of the cuttings.