# US 2025/0146401 A1 · Detection of fluid losses or gains in managed pressure drilling operations

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- Number: US 2025/0146401 A1
- Document ID: US20250146401A1
- Status: Published application
- Kind: A1
- Application number: 18/738,857
- Filed: 2024-06-10
- Published: 2025-05-08
- Earliest claimed: 2023-11-06
- Assignees: Halliburton Energy Services, Inc.
- Applicants: Halliburton Energy Services, Inc.
- Inventors: Yan Luo; Muran Han
- Web page: https://patentgrep.com/patent/US20250146401A1

## CPC

- E21B 44/00: Automatic control systems specially adapted for drilling operations, i.e. self-operating systems which function to carry out or modify a drilling operation without intervention of a human operator, e.g. computer-controlled drilling systems; Systems specially adapted for monitoring a plurality of drilling variables or conditions
- E21B 21/08: Controlling or monitoring pressure or flow of drilling fluid, e.g. automatic filling of boreholes, automatic control of bottom pressure (valve arrangements therefor E21B21/10)
- E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS

## Abstract

Disclosed embodiments relate to MPD well drilling methods, for example detecting fluid gains or losses even in transient conditions. For example, data relating to one or more parameter of the drilling system may be corrected/filtered using one or more technique. The corrected data can be used to calculate flowrate difference (DeltaFR), and possible fluid losses or gains in the system can be detected by calculating a virtual trip tank (VTT) using DeltaFR. In some embodiments, the technique can compensate for drillstring movement. In some embodiments, an adaptive moving average may be applied to the data to reduce noise. In some embodiments, bilateral filtering may be applied to the data, for example to address issues arising from movement of a choke in the drilling system. In some embodiments, updated baselines may be applied to remove any offset. Systems related to such methods are also disclosed.

## Claims

### Claim 1

A method for drilling a well using a managed pressure drilling system, comprising:
drilling a wellbore, including circulating fluid through the wellbore during drilling;
receiving, at a control system, data from one or more sensor relating to one or more parameter of the drilling system;
applying, by the control system, an adaptive moving average technique on the data to provide corrected data;
calculating, by the control system using the corrected data, a flowrate difference (DeltaFR) between flow-out rate and flow-in rate;
detecting possible fluid losses or gains by calculating, using the control system, a virtual trip tank using DeltaFR; and
responsive to detecting possible fluid losses or gains, initiating an action in the drilling system.

### Claim 2 (depends on 1)

The method of claim 1, wherein calculating the virtual trip tank (VTT) is based on VTT=Σ(DeltaFR)×Δt.

### Claim 3 (depends on 1)

The method of claim 1, wherein applying an adaptive moving average technique comprises:
evaluating quality of the data;
determining a timeframe based on the quality of the data; and
using the timeframe to determine an adaptive moving average for the data.

### Claim 4 (depends on 3)

The method of claim 3, wherein using the timeframe to determine an adaptive moving average comprises averaging the data over the timeframe.

### Claim 5 (depends on 3)

The method of claim 3 wherein evaluating the quality of the data comprises calculating a standard deviation of the data in a pre-selected timeframe, and using the standard deviation to determine quality.

### Claim 6 (depends on 1)

The method of claim 1, further comprising compensating for drillstring movement.

### Claim 7 (depends on 6)

The method of claim 6, wherein compensating for drillstring movement comprises subtracting flowrate attributable to drillstring movement from measured fluid flowrate.

### Claim 8 (depends on 6)

The method of claim 6, wherein compensating for drillstring movement comprises:
providing flowrate of drilling fluid in a drilling system;
providing depth data for the drillstring;
estimating drillstring velocity based on the depth data of the drillstring using a filter;
calculating flowrate variation caused by drillstring movement based on estimated velocity and the drillstring outer diameter; and
using the calculated flowrate variation to correct the provided flowrate,
wherein the filter for estimating drillstring velocity is a Kalman filter.

### Claim 9 (depends on 8)

The method of claim 8, further comprising, prior to applying an adaptive moving average technique, determining any phase delay; and
in the event of phase delay, accounting for phase delay prior to using the calculated flowrate variation to correct the provided flowrate.

### Claim 10 (depends on 1)

The method of claim 1, further comprising filtering parameter data to remove oscillations caused by movement of a choke manifold, wherein filtering data to remove oscillation comprises applying bilateral filtering to the data.

### Claim 11 (depends on 1)

The method of claim 1, further comprising updating and applying baselines to remove any offset.

### Claim 12 (depends on 1)

The method of claim 1, wherein calculating the flowrate difference (DeltaFR) takes into account baseline offset.

### Claim 13 (depends on 1)

The method of claim 1, further comprising monitoring, using one or more sensors, the one or more parameter including flow-in rate, flow-out rate, density, choke position, and/or drillstring velocity.

### Claim 14

A method for drilling a well using a drilling system, comprising:
drilling a wellbore;
providing data relating to one or more parameter of the drilling system;
correcting parameter data;
using the corrected data to calculate a flowrate difference (DeltaFR) between flow-out rate and flow-in rate; and
detecting possible fluid losses or gains in the system by calculating a virtual trip tank (VTT) using DeltaFR.

### Claim 15 (depends on 14)

The method of claim 14, wherein VTT is based on VTT=Σ(DeltaFR)×Δt.

### Claim 16 (depends on 15)

The method of claim 15, wherein correcting parameter data comprises applying the following to the data: an adaptive moving average technique; a bilateral filtering technique;
addressing a baseline offset; and/or compensating for drillstring movement.

### Claim 17 (depends on 16)

An MPD system for drilling a wellbore, comprising:
a control system configured to implement the method of claim 16.

### Claim 18 (depends on 17)

The system of claim 17, further comprising a drillstring disposed in a wellbore, an RCD configured to seal an annulus of the wellbore, a choke manifold in fluid communication with the annulus, and a mud pump in fluid communication with the choke manifold and the drillstring.

### Claim 19 (depends on 18)

The system of claim 18, further comprising:
a drilling fluid handling system in fluid communication with both the choke manifold and the mud pump;
a back-pressure pump configured to apply backpressure to the annulus; and
one or more sensors.

### Claim 20 (depends on 1)

A programmable storage device having program instructions stored thereon for causing a programmable control device to perform a method according to claim 1.