System and method to measure mud level in a wellbore annulus
Systems include a floating device disposed on a top of a column of drilling fluid in an annulus of a wellbore. The floating device includes a capsule. A transmitter or a reflector may be coupled to the capsule. The floating device may transmit signals to a surface region from the annulus or receive signals from the surface region and reflect at least a portion of the received signals. A receiver in the surface region receives transmitted signals or reflected signals from the floating device and determines a distance between the floating device and a reference point in the surface region. The distance indicates a level of the drilling fluid in the annulus.
1. A system comprising:
a floating device disposed on top of a column of drilling fluid in an annulus of a wellbore, the floating device comprising a capsule and at least two different types of transmitters coupled to the capsule, the at least two different types of transmitters to each emit a signal in a direction up the annulus;
at least two different types of receivers positioned in a surface region above the wellbore, the at least two different types of receivers to detect the signals emitted by the at least two different types of transmitters;
a processor in communication with the at least two different types of receivers, the processor to determine a distance between the floating device and a reference point in the surface region based on the detected signals, the distance indicative of a level of the drilling fluid in the annulus.
2. The system of claim 1 , wherein the at least one transmitter is disposed inside the capsule.
3. The system of claim 2 , further comprising a power source disposed inside the capsule and in communication with the at least one transmitter.
4. The system of claim 1 , wherein the at least one transmitter comprises an acoustic wave transmitter.
5. The system of claim 1 , wherein the at least one transmitter comprises an electromagnetic wave transmitter.
6. The system of claim 5 , wherein the electromagnetic wave transmitter comprises a light source.
7. The system of claim 1 , wherein the floating device comprises at least two transmitters emitting different types of signals, the at least two transmitters disposed inside the capsule.
8. The system of claim 7 , wherein the different types of signals comprise acoustic waves and electromagnetic waves.
9. The system of claim 1 , further comprising a flow conduit arranged in the surface region and in fluid communication with the annulus, the flow conduit having a flow outlet for outflow of drilling fluid received from the annulus.
10. The system of claim 9 , wherein the at least one receiver is positioned proximate the flow conduit.
11. The system of claim 9 , further comprising a mesh cover disposed at the flow outlet to prevent the floating device from passing through the flow outlet.
12. The system of claim 1 , further comprising a drill string disposed in the wellbore, wherein the drill string comprises a drill bit, and wherein the capsule has a size or flexibility to pass through a nozzle of the drill bit.
13. A method comprising:
deploying a floating device comprising at least one transmitter on top of a column of drilling fluid in an annulus of a wellbore;
positioning a surface device comprising at least one receiver in a surface region above the wellbore;
emitting a signal from the at least one transmitter in the floating device in a direction up the annulus;
detecting the signal emitted from the at least one transmitter at the at least one receiver;
determining a distance between the floating device and a reference point in the surface region from the detected signal:
emitting signals from two different types of transmitters included in the floating device;
detecting signals from the two different types of transmitters at two different types of receivers included in the surface device;
determining two distances between the floating device and the reference point in the surface region based on the detected signals by the two different types of receivers; and
recalibrating the distance determined between the floating device and the reference point at the surface region based on the two distances.
14. The method of claim 13 , wherein the annulus is formed between the wellbore and a drill string disposed in the wellbore, and wherein emitting the signal, detecting the signal, and determining the distance are performed during a drilling operation with the drill string.
15. The method of claim 13 , wherein the annulus is formed between the wellbore and a drill string disposed in the wellbore, and wherein emitting the signal, detecting the signal, and determining the distance are performed while pulling the drill string out of the wellbore.