Ultrasonic measurement apparatus

• US 5,317,111 A
• Filed: 01/27/1993
• Issued: 05/31/1994
• Est. Priority Date: 05/16/1990
• Status: Expired due to Term

• Current Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Original Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Inventors: Orban, Jacques, Mayes, James C.
• Primary Examiner(s): Eldred, J. Woodrow
• Application Number:
  US08/009,842
• Time in Patent Office: 489 Days
• Field of Search: 367/35, 367/25, 367/86, 367/911, 367/912, 181/105, 181/102, 175/40, 175/50, 73/152
• US Class Current: 181/105
• CPC Class Codes: B06B 1/0681 and a damping structure
• CPC Class Codes: 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
• CPC Class Codes: E21B 47/085 using radiant means, e.g. acoustic, radioactive or electromagnetic
• CPC Class Codes: E21B 47/107 using acoustic means
• CPC Class Codes: G01B 17/00 Measuring arrangements characterised by the use of infrasonic, sonic or ultrasonic vibrations
• CPC Class Codes: G01B 17/06 for measuring contours or curvatures
• CPC Class Codes: G01H 15/00 Measuring mechanical or acoustic impedance
• CPC Class Codes: G01N 2291/011 Velocity or travel time
• CPC Class Codes: G01N 2291/012 Phase angle
• CPC Class Codes: G01N 2291/015 Attenuation, scattering
• CPC Class Codes: G01N 2291/018 Impedance
• CPC Class Codes: G01N 2291/02416 Solids in liquids
• CPC Class Codes: G01N 2291/02433 Gases in liquids, e.g. bubbles, foams
• 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 29/024 by measuring propagation velocity or propagation time of acoustic waves
• CPC Class Codes: G01N 29/032 by measuring attenuation of acoustic waves
• CPC Class Codes: G01N 29/222 Constructional or flow details for analysing fluids optoacoustic fluid cells G01N29/2425
• CPC Class Codes: G01N 29/28 providing acoustic coupling , e.g. water impedance matching G10K11/02
• CPC Class Codes: G01V 1/52 Structural details

Abstract

Pulse echo apparatus and methods are disclosed for measuring characteristics of a borehole while it is being drilled. A component of a bottomhole assembly, preferably a drilling collar, is provided with one or more ultra-sonic transceivers. A pulse echo sensor of the transceiver is preferably placed in a stabilizer fin of the collar, but may also be placed in the wall of the collar, preferably close to a stabilizing fin. Electronic processing and control circuitry for the pulse-echo sensor is provided in an electronic module placed within such collar. Such pulse echo apparatus, which preferably includes two diametrically opposed transceivers, generates signals from which standoff from a borehole wall may be determined. A method and apparatus are provided for measuring standoff and borehole diameter in the presence of drilling cuttings entrained in the drilling fluid. In a preferred embodiment, such signals are assessed by the electronic processing and control circuitry to determine if gas has entered borehole. Three methods and apparatus are provided for such gas entry determination. The first relies on measurement of sonic impedance of the drilling fluid by assessing the amplitude of an echo from an interface between the drilling fluid and a delay-line placed outwardly of a ceramic sensor. The second relies on measurement of drilling fluid attenuation of a borehole wall echo. The third relies on measurement of the phase of oscillations of echoes to identify large gas bubble entries. The pulse-echo sensor includes a sensor stack including a backing element, a piezo-electric ceramic disk, and a delay-line.

Claims

1. Borehole measurement apparatus comprising,

a tool adapted for connection in a drill string in a borehole,

said tool having a generally cylindrical body defining a longitudinal axis, said cylindrical body having a substantially uniform outer diameter along its longitudinal axis, and a plurality of circumferentially spaced stabilizer blades placed about the periphery of and extending radially outwardly from said body, said blades extending longitudinally along a substantial portion of said body, and

ultra-sonic sensor means, including at least one ultra-sonic pulse-echo sensor mounted in one of said blades, said pulse-echo sensor placed substantially entirely within said stabilizer blade radially outwardly of said cylindrical body, for generating a signal indicative of a characteristic of said borehole.

2. The apparatus of claim 1 wherein said apparatus further includes electronic means for controlling the operation of said pulse-echo sensor and for processing signals received from said sensor.

3. The apparatus of claim 2 wherein said electronic means processes said signals from said pulse-echo sensor to generate a signal characteristic of the diameter of said borehole.

4. The apparatus of claim 3 wherein said electronic means processes said signals from said pulse-echo sensor to generate a signal characteristic of the presence of formation gas in borehole drilling fluid in an annulus defined by said borehole and the outside of said tool.

5. The apparatus of claim 1 wherein said ultra-sonic sensor means includes first and second transceivers mounted respectively on diametrically opposed fins.

6. Borehole measurement apparatus comprising,

a drilling collar adapted for connection in a drilling string used in the forming of said borehole, said drilling collar having a generally uniform outer diameter cylindrical body defining a longitudinal axis and a plurality of stabilizer blades circumferentially spaced about the periphery of and extending radially outwardly from said cylindrical body, and

ultra-sonic means including at least one ultra-sonic transceiver mounted in said cylindrical body near said stabilizer blades for generating a signal indicative of a characteristic of said borehole.

7. The apparatus of claim 6 wherein said transceiver is disposed a short longitudinal distance from a longitudinal position of said stabilizer blades on said cylindrical body.

8. The apparatus of claim 6 wherein said transceiver is disposed in said body at a longitudinal position that is between a pair of said stabilizer blades on said cylindrical body.