Untethered logging devices and related methods of logging a wellbore
An untethered device includes a housing, a magnetic actuator that is coupled to the housing, and a buoyancy device. The buoyancy device includes an attachment plate that is securable to the magnetic actuator, a degradable ballast weight that is coupled to the attachment plate, and a buoyancy-enhancing feature that is positioned adjacent to the attachment plate.
1. An untethered device comprising:
a housing;
a magnetic actuator that is coupled to the housing; and
a buoyancy device comprising:
an attachment plate that is securable to the magnetic actuator,
wherein the attachment plate is equipped with a buoyancy-enhancing feature, and
a degradable ballast weight that is coupled to the attachment plate,
wherein the degradable ballast weight degrades to reduce a bulk density of the buoyancy device such that the attachment plate floats towards a surface.
2. The untethered device of claim 1 , wherein the buoyancy-enhancing feature comprises a buoyant material layer.
3. The untethered device of claim 2 , wherein the buoyant material layer is disposed between the attachment plate and the degradable ballast weight.
4. The untethered device of claim 2 , wherein the buoyant material layer comprises a syntactic foam.
5. The untethered device of claim 2 , wherein the degradable ballast weight is attached directly to the buoyant material layer.
6. The untethered device of claim 5 , wherein the buoyancy device is separable as an entire unit from the magnetic actuator.
7. The untethered device of claim 1 , wherein components of the buoyancy device are secured to one another via one or more mechanical fasteners.
8. The untethered device of claim 1 , wherein components of the buoyancy device are secured to one another via one or more adhesive substances.
9. The untethered device of claim 1 , wherein the buoyancy-enhancing feature comprises void regions within the attachment plate.
10. The untethered device of claim 9 , wherein the attachment plate is attached directly to the degradable ballast weight.
11. The untethered device of claim 1 , wherein the degradable ballast weight is non-magnetic.
12. The untethered device of claim 1 , further comprising one or more sensors configured to measure one or more properties within a surrounding wellbore.
13. The untethered device of claim 1 , wherein the untethered device is configured to continuously log a surrounding wellbore while the untethered device flows in a downhole direction and while the untethered device flows in an uphole direction.
14. The untethered device of claim 1 , wherein the untethered device comprises an untethered logging device.
15. A method of logging a wellbore, the method comprising:
dropping an untethered logging device in a downhole direction through the wellbore, the untethered logging device comprising:
a functional module comprising a magnetic actuator,
an attachment plate that is equipped with a buoyancy-enhancing feature and coupled to the magnetic actuator, and
a degradable ballast weight that is attached to the attachment plate;
releasing the attachment plate from the magnetic actuator to reduce a bulk density of the untethered logging device;
flowing the functional module of the untethered logging device in an uphole direction through the wellbore;
allowing the degradable ballast weight to degrade to reduce a bulk density of an assembly of the degradable ballast weight and the attachment plate; and
flowing the attachment plate in the uphole direction through the wellbore.
16. The method of claim 15 , wherein the buoyancy-enhancing feature comprises a buoyant material layer.
17. The method of claim 16 , wherein the buoyant material layer comprises a syntactic foam.
18. The method of claim 15 , wherein the buoyancy-enhancing feature comprises void regions within the attachment plate.
19. The method of claim 15 , further comprising measuring one or more properties within the wellbore while the functional module flows in the downhole direction and in the uphole direction.