Characterization of wellbore materials in multiple casing strings

Patent metadata

Field	Value
Publication number	US-2020088901-A1
Application number	US-201615750754-A
Country	US
Kind code	A1
Filing date	Sep 14, 2016
Priority date	Sep 14, 2015
Publication date	Mar 19, 2020
Grant date	—

Abstract

Methods, systems, and computer program products for characterizing materials in a wellbore having multiple casing strings uses well completion data and instantaneous frequency, instantaneous phase, and/or amplitude attributes, including waveform amplitude and instantaneous amplitude, of an acoustic waveform to determine material densities, acoustic velocities and acoustic travel distances for the materials between the various stages of casings.

First claim

1 . A system for characterizing material in a wellbore in a subterranean formation, the wellbore having a tubing and multiple casing strings, comprising:
an acoustic tool disposed within the wellbore, the acoustic tool configured to transmit acoustic waves into the formation and record acoustic waves returning from the formation; a material assessment system configured to receive acoustic data representing the acoustic waves recorded by the acoustic tool; and an acoustic attributes evaluation tool residing in the material assessment system, the acoustic attributes evaluation tool being operable to extract one or more acoustic attributes, including instantaneous acoustic attributes, from the acoustic data and compare a measured interface time derived from the acoustic attributes with a modeled interface time derived from wellbore completion data for a material between the tubing and a casing string, between adjacent casing strings, or between a casing string and the formation; wherein the acoustic attributes evaluation tool is further operable to set the modeled interface time as the interface time for the material if an absolute difference between the modeled interface time and the measured interface time is within a predefined threshold.

2 . The computer-based system of claim 1 , wherein the material is one of:
cement, brine, or water.

3 . The computer-based system of claim 1 , wherein the acoustic attributes extracted by the acoustic attributes evaluation tool include one or more of: instantaneous acoustic frequency, acoustic amplitude, including waveform amplitude and instantaneous amplitude, or instantaneous acoustic phase.

4 . The computer-based system of claim 3 , wherein the acoustic attributes evaluation tool is further operable to generate one or more of: a first derivative of the acoustic attribute, a second derivative of the acoustic attribute, an integral of the absolute value of the acoustic attribute, or an integral of the absolute value of a derivative of the acoustic attribute.

5 . The computer-based system of claim 4 , wherein the modeled interface time is derived using an assumed acoustic velocity for the material and the acoustic attributes evaluation tool is further operable to assume a new acoustic velocity for the material if the absolute difference between the modeled interface time and the measured interface time is outside the predefined threshold.

6 . The computer-based system of claim 5 , wherein the modeled interface time is derived using an assumed density for the material and the acoustic attributes evaluation tool is further operable to assume a new density for the material if the new acoustic velocity is outside a predefined minimum and maximum velocity.

7 . The computer-based system of claim 6 , wherein the acoustic attributes evaluation tool is further operable to derive a new measured interface time if the new density is outside a predefined minimum and maximum density.

8 . A method for characterizing material in a wellbore in a subterranean formation, the wellbore having a tubing and multiple casing strings, comprising:
transmitting acoustic waves into the borehole and recording acoustic waves returning from the wellbore; receiving acoustic data representing the recorded acoustic waves returning from the formation; and extracting one or more acoustic attributes, including instantaneous acoustic attributes, from the acoustic data representing the recorded acoustic waves; comparing a measured interface time derived from the acoustic attributes with a modeled interface time derived from wellbore completion data for a material between the tubing and a casing string, between adjacent casing strings, or between a casing string and the formation; and setting the modeled interface time as the interface time for the material if an absolute difference between the modeled interface time and the measured interface time is within a predefined threshold.

9 . The method of claim 8 , wherein the material is one of: cement, brine, or water.

10 . The method of claim 9 , wherein the acoustic attributes include one or more of: instantaneous acoustic frequency, acoustic amplitude, including waveform amplitude and instantaneous amplitude, or instantaneous acoustic phase.

11 . The method of claim 10 , further comprising generating one or more of: a first derivative of the acoustic attribute, a second derivative of the acoustic attribute, an integral of the absolute value of the acoustic attribute, or an integral of the absolute value of a derivative of the acoustic attribute.

12 . The method of claim 11 , wherein the modeled interface time is derived using an assumed acoustic velocity for the material, further comprising assuming a new acoustic velocity for the material if the absolute difference between the modeled interface time and the measured interface time is outside the predefined threshold.

13 . The method of claim 12 , wherein the modeled interface time is derived using an assumed density for the material, further comprising assuming a new density for the material if the new acoustic velocity is outside a predefined minimum and maximum velocity.

14 . The method of claim 13 , further comprising deriving a new measured interface time if the new density is outside a predefined minimum and maximum density.

15 . A computer-readable medium storing computer-readable instructions for characterizing material in a wellbore in a subterranean formation, the wellbore having a tubing and multiple casing strings, the computer-readable instructions causing a computing system to:
receive acoustic data representing recorded acoustic waves returning from the formation; extract one or more acoustic attributes, including instantaneous acoustic attributes, from the acoustic data representing the recorded acoustic waves; compare a measured interface time derived from the acoustic attributes with a modeled interface time derived from wellbore completion data for a material between the tubing and a casing string, between adjacent casing strings, or between a casing string and the formation; and set the modeled interface time as the interface time for the material if an absolute difference between the modeled interface time and the measured interface time is within a predefined threshold.

16 . The computer-readable medium of claim 15 , wherein the material is one of: cement, brine, or water.

17 . The computer-readable medium of claim 15 , wherein the acoustic attributes include one or more of: instantaneous acoustic frequency, acoustic amplitude, including waveform amplitude and instantaneous amplitude, or instantaneous acoustic phase.

18 . The computer-readable medium of claim 17 , wherein the computer-readable instructions further cause the computing system to generate one or more of: a first derivative of the acoustic attribute, a second derivative of the acoustic attribute, an integral of the absolute value of the acoustic attribute, or an integral of the absolute value of a derivative of the acoustic attribute.

19 . The computer-readable medium of claim 18 , wherein the modeled interface time is derived using an assumed acoustic velocity for the material, the computer-readable instructions further cause and the computing system to assume a new acoustic velocity for the material if the absolute difference between the modeled interface time and the measured interface time is outside the predefined threshold.

20 . The computer-readable medium of claim 19 , wherein the modeled interface time i

Assignees

• Halliburton Energy Services Inc

Inventors

• Quintero Luis F
• Zheng Yibing
• Kirkwood Andrew

Classifications

• E21B47/005

  Monitoring or checking of cementation quality or level · CPC title

• G01V2210/42

  Waveform, i.e. using raw or pre-filtered trace data · CPC title

• G01V2210/6222

  Velocity; travel time · CPC title

• G01V1/40

  specially adapted for well-logging · CPC title

• G01V2210/63

  Seismic attributes, e.g. amplitude, polarity, instant phase · CPC title