Fluid Lift System

Abstract

A fluid lift system includes a canister defining a cavity for lifting fluid and an orifice at an upper portion of the canister extending to the cavity, a reel, and a cable operably associated with the reel and the canister. The fluid lift system further includes a motor operatively associated with the reel, the motor operable to raise and lower the canister and a head housing defining a bore in which the upper portion of the canister is sealingly received, the head housing defining a port extending into the cavity. The fluid lift system further includes a pump in fluid communication with the head housing, the pump operable to vacuum lifted fluid from the cavity of the canister through the orifice and the port and a control system for operating the motor and the pump.

1 . (canceled) 
   
   
       2 . A fluid lift system, comprising:
 a canister defining a cavity for lifting fluid and an orifice at an upper portion of the canister extending to the cavity;   a reel;   a cable operably associated with the reel and the canister;   a motor operatively associated with the reel, the motor operable to raise and lower the canister;   a head housing defining a bore in which the upper portion of the canister is sealingly received, the head housing defining a port extending into the cavity;   a pump in fluid communication with the head housing, the pump operable to vacuum lift fluid from the cavity of the canister through the orifice and the port;   a control system for operating the motor and the pump; and   a load-indicating shaft mechanically linking the motor and the reel and operatively associated with the control system.   
   
   
       3 . The fluid lift system, according to  claim 2 , wherein the control system is operable to determine contact between the canister and a top of a fluid pad based at least upon a signal from the load-indicating shaft. 
   
   
       4 . The fluid lift system, according to  claim 2 , wherein the control system is operable to place the canister a predefined distance below the top of the fluid pad based at least upon a signal from the load-indicating shaft. 
   
   
       5 . The fluid lift system, according to  claim 2 , wherein the control system is operable to determine if the canister enters a water portion based at least upon a signal from the load-indicating shaft. 
   
   
       6 . The fluid lift system, according to  claim 5 , wherein the control system is operable to move the canister from the water portion into the fluid pad. 
   
   
       7 . The fluid lift system, according to  claim 2 , further comprising:
 a storage tank in fluid communication with the pump for temporarily storing lifted fluid.   
   
   
       8 . The fluid lift system, according to  claim 7 , further comprising:
 a level sensor operatively associated with the tank and the control system for sensing a level of fluid in the tank.   
   
   
       9 . The fluid lift system, according to  claim 8 , wherein the control system is operable to pump the fluid from the tank based at least upon a signal from the level sensor. 
   
   
       10 . A fluid lift system, comprising:
 a canister defining a cavity for lifting fluid and an orifice at an upper portion of the canister extending to the cavity;   a reel;   a cable operably associated with the reel and the canister;   a motor operatively associated with the reel, the motor operable to raise and lower the canister;   a head housing defining a bore in which the upper portion of the canister is sealingly received, the head housing defining a port extending into the cavity;   a pump in fluid communication with the head housing, the pump operable to vacuum lift fluid from the cavity of the canister through the orifice and the port;   a control system for operating the motor and the pump;   a storage tank in fluid communication with the pump for temporarily storing lifted fluid;   a first three-way valve in fluid communication with the head housing, the pump, and the tank; and   a second three-way valve in fluid communication with the pump and the tank, the second three-way valve having a recovery line outlet port.   
   
   
       11 . The fluid lift system, according to  claim 2 , further comprising:
 a traveling sheave operably associated with the cable.   
   
   
       12 . The fluid lift system, according to  claim 2 , further comprising:
 an elastomeric member disposed in the bore of the head housing for sealingly receiving the upper portion of the canister.   
   
   
       13 . The fluid lift system, according to  claim 12 , wherein the elastomeric member and the upper portion of the canister define radiused sealing surfaces, such that the radiused sealing surface of the canister mates with the radiused sealing surface of the elastomeric member. 
   
   
       14 . The fluid lift system, according to  claim 2 , further comprising:
 a swivel attached to the cable and operably associated with the canister.   
   
   
       15 . A method of lifting fluid, comprising the steps of:
 providing a canister, a reel, a cable, a cable operably associated with the reel and the canister, a motor for operating the reel to raise and lower the canister, and a load-indicating shaft mechanically linking the motor and the reel;   lowering the canister into a well;   monitoring an output of the load-indicating shaft to detect a depth at which contact is made between the canister and a top of a fluid pad;   lowering the canister to a predetermined depth below the top of the fluid pad;   waiting for the canister to at least partially fill with fluid;   raising the canister; and   vacuuming the fluid from the canister.   
   
   
       16 . (canceled) 
   
   
       17 . The method, according to  claim 15 , further comprising the step of:
 detecting whether the canister has entered a second fluid pad having a density different from the fluid pad.   
   
   
       18 . The method, according to  claim 17 , wherein the step of detecting whether the canister has entered the second fluid pad is accomplished by sensing a change in a weight of the canister. 
   
   
       19 . The method, according to  claim 15 , further comprising the step of:
 determining the predetermined depth based at least upon the depth at which contact is made between the canister and the fluid pad.   
   
   
       20 . The method, according to  claim 15 , further comprising the step of:
 collecting gases expelled from a well in which the fluid is disposed.   
   
   
       21 . The fluid lift system, according to  claim 2 , wherein the load-indicating shaft comprises:
 a load sensor; and   a signal conditioner operably associated with the load sensor and the control system.   
   
   
       22 . The fluid lift system, according to  claim 21 , wherein the load sensor comprises:
 a plurality of strain gauges.