Gas Lift Valve Actuated by Downhole Sensor

Technology #15757

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FIG. 1 is a schematic diagram of an example environment in which an embodiment of a thermally-actuated gas lift safety valve may be implemented.FIG. 2 is a schematic diagram that generally depicts an embodiment of a thermally-actuated gas lift safety valve.FIG. 3 is a schematic diagram that shows a partial cut-away, side elevation view of an embodiment of a thermally-actuated gas lift safety valve in which a shape memory alloy element can be incorporated.
Categories
Inventors
Professor Franz Hover
Department of Mechanical Engineering, MIT
External Link (meche.mit.edu)
Changkuan Yu
Department of Mechanical Engineering, MIT
Eric Gibertson
Department of Mechanical Engineering, MIT
Dennis Harris
Chevron Corporation
Jose Arrellano
Chevron Corporation
Managed By
Christopher Noble
MIT Technology Licensing Officer - Clean and Renewable Energy
Patent Protection

Gas-lift safety valve actuated by a sensor

US Patent 9,284,825
Publications
A Thermally-Actuated Gas Lift Safety Valve
SPE Production and Operations, Vol. 28, No. 01 (2013): 77-84
Sharp Phase Change in Shape Memory Alloy Thermal Actuators for Subsea Flow Control
ASME International Conference on Offshore Mechanics and Artic Engineering (OMAE), Rio de Janiero, Brazil, July 2012
Design of a Thermally-Actuated Gas Lift Safety Valve
ASME International Conference on Offshore Mechanics and Arctic Engineering (OMAE) , Rotterdam, Netherlands, June 2011
Gas Lift Valve Failure Mode Analysis and the Design of a Thermally-Actuated Positive-Locking Safety Valve
Masters Thesis, Massachusetts Institute of Technology, 2010


Applications

Gas-lifted oil wells

Problem Addressed

 

In a gas-lifted well, it is possible for product to pass from the tubing into the annulus if two conditions are simultaneously met: (1) the reverse-flow check valve has a leak and the tubing pressure exceeds the gas pressure, (2) a combination of high tubing pressure and low gas pressure allows the bellows valve to open. If both the check valve and the bellows valve leak, then backflow can occur any time tubing pressure exceeds annulus pressure.

Technology

The invention is an apparatus within a gas lift valve that senses the presence of oil. This sensor is a conductivity sensor. Oil has a different conductivity than injection gas and when the sensor detects an increase in conductivity, it causes an electronic circuit to heat a shape-memory-alloy wire, which contracts to close a safety valve.

Advantages

  • Prevents oil backflow through a gas lift valve
  • Improved response time of valve 
  • Drastically reduced false actuations