Embedded electrode tuning fork
AssigneeBaker Hughes Oilfield Operations LLC
InventorsRocco DiFoggio, Yi Liu
Life of this patent
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Abstract
A sensor for obtaining downhole data includes a first piezoelectric layer. The sensor also includes a second piezoelectric layer having a trench extending a depth below a surface of the second piezoelectric layer. The sensor also includes an electrode positioned within the trench. The first piezoelectric layer is directly coupled to the second piezoelectric layer.
Claims20
An apparatus for obtaining downhole fluid density and viscosity, comprising:
- a first piezoelectric layer;
- a second piezoelectric layer having at least one trench extending a depth below a surface of the second piezoelectric layer;
- an electrode positioned within the at least one trench;
- and
- a gap between the electrode and the first piezoelectric layer;
- wherein the first piezoelectric layer and the second piezoelectric layer are formed from a common material and are directly bonded together to form a seal between the first piezoelectric layer and the second piezoelectric layer to block fluid ingress into the at least one trench.
A system for obtaining in a downhole environment a fluid density and a viscosity, comprising:
- a segment forming at least a portion of a downhole tool, the downhole tool being conveyable into a wellbore;
- a tuning fork, forming at least a portion of the segment, configured to evaluate at least one of viscosity or fluid density in the downhole environment, comprising:
- a first layer formed from a piezoelectric material;
- a second layer formed from the piezoelectric material directly bonded to the first layer to form a seal between the first layer and the second layer;
- an electrode positioned within the second layer;
- a gap formed between the electrode and the first layer;
- and
- a connector arranged at an end of the second layer.
A method for forming a downhole fluid density and viscosity tool, comprising:
- providing a second layer, the second layer being formed from a piezoelectric material;
- forming at least one trench in the second layer, the at least one trench extending below a surface of the second layer;
- filling a portion of the at least one trench with an electrode;
- preparing the surface of the second layer to a roughness below a threshold value;
- bonding a first layer, formed from the piezoelectric material, directly to at least a portion of the second layer to form a seal between the first layer and the second layer to block fluid ingress into the at least one trench;
- and
- maintaining, prior to the bonding, a gap between the electrode and the first layer.
Dependencies are inferred from the claim text.