Patent ID: 11879328
Assignee: SAUDI ARABIAN OIL COMPANY
Field: Civil engineering (Other fields)
Classification: CPC E | IPC E

Claim 0:
1. An untethered measurement tool (UMT) for logging data at a fixed location in a wellbore, the UMT comprising:
a housing comprising weights to control orientation of the UMT, wherein the housing is formed from a material that is buoyant in fluids in the wellbore;
an unpowered magnet that is switchable between an external field state and a circular field state, wherein the external field state couples the UMT to a ferromagnetic surface;
a power boost circuit to charge a capacitor to switch a state of the unpowered magnet;
a sensor configured to measure data in the wellbore; and
a controller, comprising:
a processor; and
a non-transitory storage medium, wherein the non-transitory storage medium comprises instructions to direct the processor to:
measure data correlating to a depth in the wellbore;
switch the unpowered magnet to the circular field state at a target depth, dropping an attached ballast;
switch the unpowered magnet to the external field state, coupling the UMT to a wall of the wellbore;
log data from the sensor to the storage medium; and
switch the unpowered magnet to the circular field state to release the UMT,

wherein the weights cause the UMT to change from a first orientation to a second orientation in response to dropping the attached ballast,
wherein the first orientation directs the unpowered magnet toward a downhole direction during descent of the UMT in the wellbore, and
wherein the second orientation directs the unpowered magnet toward a horizontal direction during ascent of the UMT in the wellbore to facilitate coupling the UMT to the wall of the wellbore.