# US 12,760,645 B2 · Gas composition from a drilling fluid density change

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- Number: US 12,760,645 B2
- Document ID: US12760645B2
- Status: Granted
- Kind: B2
- Application number: 18/082,273
- Filed: 2022-12-15
- Published: 2024-06-20
- Granted: 2026-10-13
- Earliest claimed: 2022-12-15
- Assignees: Halliburton Energy Services, Inc.
- Applicants: Halliburton Energy Services, Inc.
- Inventors: Jhanvi Manishkumar Kevadiya; Mathew Dennis Rowe
- Web page: https://patentgrep.com/patent/US12760645B2

## CPC

- E21B 49/0875: {determining specific fluid parameters}
- 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

Described herein are systems and techniques for improving operation of equipment that identify compounds included in a slurry that exits a wellbore during a drilling operation. Mass flow rates, volumetric data, wellbore equipment data, and other information may be used to identify a total volumetric density of the slurry. Calculations and/or other evaluations may be performed to identify a volumetric density of materials other than a gas included in the slurry. The volumetric density of the other materials may be subtracted from the total volumetric density to identify a volumetric density of the gas included in the slurry. Estimates of percentages of hydrocarbons and molar mass equations may be used to estimate masses of combined sets of hydrocarbons included in the gas. When a volumetric density of a combined set of hydrocarbons matches the gas volumetric density, the gas may be classified as including the set of hydrocarbons.

## Claims

### Claim 1

A method comprising:
identifying a set of metrics of an initial composition of a drilling mud provided to a wellbore, the set of metrics including a first metric associated with a fraction of a clay and a second metric associated with a fraction of a solid included in the initial composition of the drilling mud provided to the wellbore;
calculating a density of the initial composition of the drilling mud as a function of the first metric associated with the fraction of the clay and the second metric associated with the fraction of the solid included in the initial composition of the drilling mud;
wherein the initial composition of the drilling mud is changed to a changed composition of the drilling mud after the initial composition of the drilling mud is provided to the wellbore;
wherein the changed composition of the drilling mud includes a fraction of gasses and an estimated rock mass; and
wherein the density of the initial composition of the drilling mud is calculated by determining a constituent volumetric density of each of the clay, the solid, and a fluid within the initial composition based on the fraction of each of the clay and the solid included in the initial composition and a volumetric density of each of the clay and the solid included in the initial composition;
calculating a density of the changed composition that includes the fraction of gasses and the estimated rock mass;
identifying a density difference by subtracting the density of the changed composition from the density of the initial composition;
identifying the fraction of gasses included in the changed composition based on the density difference and the estimated rock mass;
predicting a composition of the fraction of gasses included in the changed composition based on the density difference; and
adjusting a drilling operation based on the predicted composition of the fraction of gasses.

### Claim 2 (depends on 1)

The method of claim 1, further comprising:
identifying a mass flow rate of the initial composition of the drilling mud provided to the wellbore; and
identifying a mass flow rate of the changed composition as the changed composition exits the wellbore.

### Claim 3 (depends on 1)

The method of claim 1, wherein the density of the initial composition of the drilling mud (Pmudin) is calculated by applying an equation of:
Pmudin=[(ΦCin)*PC]+[(ΦSin)*PS]+[(1−ΦCin−ΦSin)*Pfluid], where:
ΦCin is the first metric associated with the fraction of the clay included in the initial composition of the drilling mud,
ΦSin is the second metric associated with the fraction of solid included in the initial composition of the drilling mud,
PC is the volumetric density of the clay,
PS is the volumetric density of the solid, and
Pfluid is a volumetric density of the fluid included in the initial composition of the drilling mud, wherein the initial composition of the drilling mud is changed to a changed composition after the drilling mud is provided to the wellbore.

### Claim 4 (depends on 3)

The method of claim 3, wherein the density of the changed composition of the drilling mud is calculated by applying an equation of:
Pmudf=[ΦCf*PC]+[ΦSf*PS]+[Φ*PK]+[(1−ΦCf−ΦSf−Φkf)*Pfluidf], where
where:
ΦCf is a fraction of the clay included in the changed composition,
ΦSf is a fraction of the solid included in the changed composition,
Φkf is a fraction of drill cuttings included in the changed composition, wherein the drill cuttings include a rock mass,
PK is a volumetric density of the drill cuttings included in the changed composition, and
Pfluidf is a volumetric density of a fluid included in the changed composition.

### Claim 5 (depends on 1)

The method of claim 1, wherein:
the first metric corresponds to a volumetric percentage of the clay in the initial composition of the drilling mud, and
the second metric corresponds to a volumetric percentage of the solid in the initial composition of the drilling mud.

### Claim 6 (depends on 1)

The method of claim 1, further comprising:
identifying a specific gravity of a rock included in the changed composition, the specific gravity of the rock included in the changed composition corresponding to the mass of the rock in a volume of the changed composition.

### Claim 7 (depends on 6)

The method of claim 6, wherein the specific gravity of the rock is identified by:
acquiring an image of the rock included in the changed composition; and
performing an evaluation of the image that identifies the specific gravity of the rock by estimating the mass of the rock included in the volume of the changed composition.

### Claim 8 (depends on 6)

The method of claim 6, further comprising:
calculating a density of drill cuttings (PCut), by applying an equation of:
PCut=(the specific gravity of the rock)*(density of water)*[(a measured volume of the rock)/(a drilled volume per-unit-time)].

### Claim 9 (depends on 8)

The method of claim 8, further comprising:
identifying the drilled volume (V) per-unit-time (Δ Time) by applying an equation of:
V=(drill bit area)*(penetration rate)*(Δ Time).

### Claim 10 (depends on 4)

The method of claim 4, further comprising:
calculating a change in fluid density (ΔPfluid) by applying:
ΔPfluid=Pfluidf−Pmudin−[Φkf*PK]

### Claim 11 (depends on 7)

The method of claim 7, further comprising:
estimating a fraction of gas compositions included in the changed composition based on a relationship of:
ΔPfluid=Σ[(a fraction concentration of the gasses)*(gas density)], when:
Σ (the fraction concentration of the gasses)=1, and
0≤the fraction of the gasses≤1.

### Claim 12 (depends on 2)

The method of claim 2, wherein the mass flow rate of the initial composition of the drilling mud provided to the wellbore is identified based on the initial composition of the drilling mud flowing through a mass flow meter.

### Claim 13 (depends on 12)

The method of claim 12, wherein the mass flow rate of the changed composition is identified based at least in part on a portion of the changed composition flowing through the mass flow meter or a second mass flow meter.

### Claim 14

A system comprising:
a memory; and
one or more processors that execute instructions out of the memory to:
identify a set of metrics of an initial composition of a drilling mud provided to a wellbore, the set of metrics including a first metric associated with a fraction of a clay and a second metric associated with a fraction of a solid included in the initial composition of the drilling mud provided to the wellbore;
calculate a density of the initial composition of the drilling mud as a function of the first metric associated with the fraction of the clay and the second metric associated with the fraction of the solid included in the initial composition of the drilling mud:
wherein the initial composition of the drilling mud is changed to a changed composition of the drilling mud after the initial composition of the drilling mud is provided to the wellbore;
wherein the changed composition of the drilling mud includes a fraction of gasses and an estimated rock mass; and
wherein the density of the initial composition of the drilling mud is calculated by determining a constituent volumetric density of each of the clay, the solid, and a fluid within the initial composition based on the fraction of each of the clay and the solid included in the initial composition and a volumetric density of each of the clay and the solid included in the initial composition;
calculate a density of the changed composition that includes the fraction of gasses and the estimated rock mass;
identify a density difference by subtracting the density of the changed composition from the density of the initial composition;
identify the fraction of gasses included in the changed composition based on the density difference and the estimated rock mass;
predict a composition of the fraction of gasses included in the changed composition based on the density difference; and
adjusting a drilling operation based on the predicted composition of the fraction of gasses.

### Claim 15 (depends on 14)

The system of claim 14, further comprising:
one or more mass flow meters that measure:
a mass flow rate of the initial composition of the drilling mud provided to the wellbore, and
a mass flow rate of the changed composition as the changed composition exits the wellbore.

### Claim 16 (depends on 14)

The system of claim 14, wherein:
the first metric corresponds to a volumetric percentage of the clay in the initial composition of the drilling mud, and
the second metric corresponds to a volumetric percentage of the solid in the initial composition of the drilling mud.

### Claim 17 (depends on 14)

The system of claim 14, wherein in the one or more processors execute the instructions to:
identify a specific gravity of rock included in the changed composition, the specific gravity of the rock included in the changed composition corresponding to the mass of the rock in a volume of the changed composition.

### Claim 18 (depends on 17)

The system of claim 17, wherein the specific gravity of the rock is identified by:
acquiring an image of the rock included in the changed composition; and
performing an evaluation of the image that identifies the specific gravity of the rock by estimating the mass of the rock included in the volume of the changed composition.

### Claim 19 (depends on 15)

The system of claim 15, wherein the mass flow rate of the initial composition of the drilling mud provided to the wellbore is identified based on the initial composition of the drilling mud flowing through the one or more mass flow meters.

### Claim 20

A non-transitory computer-readable storage medium having embodied thereon instructions executable by one or more processors to implement a method comprising:
identifying a set of metrics of an initial composition of a drilling mud provided to a wellbore, the set of metrics including a first metric associated with a fraction of a clay and a second metric associated with a fraction of a solid included in the initial composition of the drilling mud provided to the wellbore;
calculating a density of the initial composition of the drilling mud as a function of the first metric associated with the fraction of the clay and the second metric associated with the fraction of the solid included in the initial drilling mud:
wherein the initial composition of the drilling mud is changed to a changed composition of the drilling mud after the initial composition of the drilling mud is provided to the wellbore;
wherein the changed composition of the drilling mud includes a fraction of gasses and an estimated rock mass; and
wherein the density of the initial composition of the drilling mud is calculated by determining a constituent volumetric density of each of the clay, the solid, and a fluid within the initial composition based on the fraction of each of the clay and the solid included in the initial composition and a volumetric density of each of the clay and the solid included in the initial composition;
calculating a density of the changed composition that includes the fraction of gasses and the estimated rock mass;
identifying a density difference by subtracting the density of the changed composition from the density of the initial composition;
identifying the fraction of gasses included in the changed composition based on the density difference and the estimated rock mass;
predicting a composition of the fraction of gasses included in the changed composition based on the density difference; and
adjusting a drilling operation based on the predicted composition of the fraction of gasses.