Patent ID: 11913329
Assignee: SAUDI ARABIAN OIL COMPANY
Field: Civil engineering (Other fields)
Classification: CPC E | IPC E

Claim 14:
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.