METHOD AND DEVICE FOR ON-LINE ACOUSTIC MONITORING OF FOAM AND AERATED FLUID PROPERTIES

• US 20090006005A1
• Filed: 12/20/2007
• Published: 01/01/2009
• Est. Priority Date: 12/28/2006
• Status: Active Grant

• Current Assignee: Schlumberger Technology Corporation (SLB)
• Original Assignee: Schlumberger Technology Corporation (SLB)
• Inventors: Thiercelin, Mark Jean, Segal, Arkady Yurevich
• Granted Patent: US 7,769,549 B2
• Time in Patent Office: Days
• US Class Current: 702/24
• CPC Class Codes: G01H 5/00 Measuring propagation velocity of ultrasonic, sonic or infrasonic waves , e.g. of pressure waves
• CPC Class Codes: G01N 2291/02433 Gases in liquids, e.g. bubbles, foams
• CPC Class Codes: G01N 2291/02836 Flow rate, liquid level
• CPC Class Codes: G01N 2291/102 one emitter, one receiver
• CPC Class Codes: G01N 29/02 Analysing fluids using acoustic emission techniques G01N29/14 ; constructional or flow details for analysing fluids G01N29/222; optoacoustic fluid cells G01N29/2425
• CPC Class Codes: G01N 29/07 by measuring propagation velocity or propagation time of acoustic waves

Abstract

A method and device for on-line foam quality acoustic monitoring are suggested. As per the invention, the method provides for the following: at least one emitter/receiver pair is placed in a close vicinity to the foam flow; at least one acoustic pulse is emitted; time, within which the acoustic pulse overcomes the way from the emitter to the receiver, is recorded; acoustic pulse speed (sound speed) is determined by analyzing an acoustic response of the receiver. After that, pressure in the foam in the area between the emitter and receiver is defined and the foam quality Γ is calculated as per the equation:

$\Gamma =\frac{1}{2}\pm \sqrt{\frac{1}{4}-\frac{N}{{\rho }_{\mathrm{fl}}}\frac{p}{C_{\mathrm{fm}}^2}},$

where: C_fm—speed of sound in the foam, p—pressure, ρ_fl—fluid density, Γ—foam quality, N—polytrophic expansion coefficient (N=1 for isothermal process; N=1.4 for adiabatic process), in case of a foam composed of a perfect gas and a perfect fluid for cases, when the foam quality is supposedly much lower than ½ or much bigger than ½, the sign to be selected in the said formula is <<−>> and <<+>>, respectively; in cases when both values of Γ are near ½, the both quality values should be considered as a possible option, or in more complicated cases, it can be found from the Value Spreadsheet

Claims

1. A method of on-line foam quality acoustic monitoring embedding the following:

at least one emitter/receiver pair is placed in close vicinity to the foam flow,

at least one acoustic pulse is emitted,

travel time, within which the acoustic pulse overcomes the way from the emitter to the receiver, is recorded,

acoustic pulse speed (sound speed) is determined by analyzing an acoustic response of the receiver,

pressure in the foam in the area between the emitter and receiver is defined,

foam quality Γ

is calculated using the equation;

2. A method according to claim 1, with the difference that at least one emitter/receiver pair is moved along the foam flow path and sound speed is measured at several points en-route the foam flow to obtain foam quality distribution along the flow path.

3. A method according to claim 1, with the difference that an emitter/receiver pair is installed at the wellhead or in close vicinity of the wellhead to emit sound at the foam flow beginning and to receive a signal reflected from the foam flow end.

4. A method according to claim 1, with the difference that pressure along at least one extended section en-route the foam flow path is measured to monitor uninterrupted foam quality distribution.

5. A device for on-line foam quality acoustic monitoring comprising:

at least one emitter/receiver pair located in close vicinity of the foam flow and intended to emit at least one acoustic pulse and to receive at least one acoustic response,

a logger to record the time required for the acoustic pulse to travel from the emitter to the receiver,

pressure transducer placed between the emitter and the receiver, and

data processing unit connected to at least one emitter/receiver, the logger and pressure transducer, which is intended to calculate the sound speed using the acoustic pulse travel time, and to calculate the foam quality Γ

based on data received from the equation;

6. A device according to claim 5, with the difference that at least one emitter/receiver pair could move along the foam flow direction to measure sound speed at several points downstream of the foam flow to obtain the foam quality vs. flow direction profile.

7. A device according to claim 5, with the difference that at least one emitter/receiver pair is located in a close vicinity to the wellhead to emit sound at the foam flow beginning and to receive a signal reflected from the foam flow end.

8. A method of on-line acoustic monitoring of the quality of a foam applied for well cementing and formation fracturing, which provides the following:

at least one emitter/receiver pair is placed in close vicinity to the foam flow,

at least one acoustic pulse is emitted,

travel time, within which the acoustic pulse overcomes the way from the emitter to the receiver, is recorded,

acoustic pulse speed (sound speed) is determined by analyzing an acoustic response of the receiver,

pressure in the foam in the area between the emitter and receiver is defined, foam quality Γ

is calculated using the equation;