Measuring device

Abstract

A downhole device for measuring the fluid flow in a wellbore comprising a housing, a power supply, a motor control, a motor coupled to a spinner, viscosity, pressure and temperature measurement sensors, wherein a pressure compensation system comprising a spring means supported by a spring holder, a piston in contact with the spring, a pressure compensation fluid chamber and seals sealing the pressure compensation chamber against the piston.

1 . A downhole device for measuring the fluid flow in a wellbore comprising a housing, a power supply, a motor control, a motor coupled to a spinner and viscosity, pressure and temperature measurement sensors, characterized by a pressure compensation system comprising a spring means supported by a spring holder, a piston in contact with the spring means, a pressure compensation fluid chamber and seals sealing the pressure compensation chamber against the piston. 
     
     
         2 . The device of  claim 1 , wherein the power supply is a battery. 
     
     
         3 . The device of  claim 1 , wherein the spring means is a compression spring. 
     
     
         4 . The device of  claim 3 , wherein the spring means his mounted on and guided by a spring holder. 
     
     
         5 . The device of  claim 1 , wherein the piston is a guided within a ceramic sleeve. 
     
     
         6 . The device of  claim 5 , wherein the seals sealing the pressure compensation fluid chamber against the piston are mounted on the piston. 
     
     
         7 . The device of  claim 1 , wherein the seals are O-rings. 
     
     
         8 . The device of  claim 7 , wherein the seals are U-cup rings. 
     
     
         9 . The device of  claim 1 , wherein the pressure compensation fluid chamber has a filling port. 
     
     
         10 . The device of  claim 1  comprising two pressure and two and two temperature sensors allowing differential measurements. 
     
     
         11 . The device of  claim 1  comprising flow rate and flow velocity sensors. 
     
     
         12 . The device of  claim 1  further comprising means for data storage and/or wireless data transmission.