Pump Drain Arrangements For Packer Systems And Methods For Sampling Underground Formations Using Same

Abstract

An apparatus, system and method of sampling a reservoir fluid is disclosed. An inflatable packer is deployed into a wellbore having one or more fluid ports for receiving the reservoir fluid. The fluid ports are positionable at different longitudinal and/or radial positions. One or more pumps are connected to the fluid ports and are within the packer. A fluid exit may optionally be provided in the packer to expel the reservoir fluid received from one of the fluid ports back into the wellbore.

What is claimed is: 
     
         1 . A method comprising:
 positioning an inflatable packer in a wellbore;   inflating the packer from a first diameter to a second diameter greater than the first diameter to fluidly connect a sample drain and a guard drain with reservoir fluid wherein the guard drain is positioned at a longitudinal distance closer to an end of the packer than a longitudinal distance from the sample drain to the end of the packer; and   pumping the reservoir fluid from the wellbore through the guard drain or the sample drain with a pump positioned within the packer.   
     
     
         2 . The method according to  claim 1  wherein the pumping comprises pumping the reservoir fluid through the guard drain at a first rate and pumping the reservoir fluid through the sample drain at a second rate different than the first rate. 
     
     
         3 . The method according to  claim 1  wherein the sample drain and the guard drain are radially separated a distance along the packer. 
     
     
         4 . The method according to  claim 1  further comprising:
 cleaning at least one of the sample drain and the guard drain prior to withdrawing the reservoir fluid. 
 
     
     
         5 . The method according to  claim 1  further comprising:
 expelling at least a portion of the reservoir fluid from the packer into the wellbore. 
 
     
     
         6 . The method according to  claim 4  wherein the cleaning comprises receiving fluid through the sample drain or the guard drain and ejecting the fluid from the packer into the wellbore without passing the fluid out of the packer. 
     
     
         7 . The method according to  claim 1  further comprising pumping the reservoir fluid from the sample drain and the guard drain with different pumps. 
     
     
         8 . The method according to  claim 7  wherein the pumping comprises pumping fluid through the guard drain at a first rate and pumping fluid through the sample drain at a second rate, and further wherein the first rate is different than the second rate. 
     
     
         9 . An apparatus, comprising:
 a body having a guard drain and a sample drain providing fluid access from an external of the body to an internal of the body, the body inflatable from a first diameter to a second diameter greater than the first diameter, the guard drain located a longitudinal distance from the sample drain;   a fluid exit positioned within the body to expel fluid received from the guard drain or the sample drain out of the body; and   at least one pump within the body and fluidly connected to the guard drain or the sample drain.   
     
     
         10 . The apparatus of  claim 9  wherein the body includes an elastomeric seal layer configured to seal against a wall of a wellbore. 
     
     
         11 . The apparatus of  claim 9  wherein the at least one pump is positioned at the guard drain or the sample drain. 
     
     
         12 . The apparatus according to  claim 9 , wherein the at least one pump is one of a hydraulically actuated pump, a pump activated by an electrical motor, a positive displacement pump, a progressive cavity pump, and a piston pump. 
     
     
         13 . The apparatus according to  claim 9  wherein the at least one pump is configured to draw fluid into the guard drain or the sample drain and pump the fluid through the fluid exit. 
     
     
         14 . The apparatus of  claim 9  wherein the at least one pump includes a first pump in fluid communication with the guard drain and a second pump in fluid communication with the sample drain. 
     
     
         15 . The apparatus of  claim 9  wherein the at least one pump moves fluid from the guard drain into the body and expels the fluid out of the body. 
     
     
         16 . The apparatus of  claim 9  wherein the at least one pump moves fluid from the sample drain into the body and expels the fluid out of the body. 
     
     
         17 . The apparatus of  claim 14  wherein the first pump and the second pump operate at different rates and are individually controllable. 
     
     
         18 . The apparatus of  claim 14  wherein the first pump or the second pump is positioned in the guard drain or the sample drain.