Attenuation mapping apparatus, systems, and methods
In some embodiments, an apparatus and a system, as well as a method and an article, may include generating attenuation values associated with a set of multiple signals received by multiple receivers from a transmitted signal as a function of reception time and material velocity. The attenuation values may be stored in a memory and/or displayed on a display, perhaps in conjunction with a semblance map.
1. A method, including:
initiating a first transmitted signal into material comprising a geologic formation;
generating averaged compensated attenuation values associated with a first set of multiple signals received by multiple receivers along multiple paths between the multiple receivers from the first transmitted signal as a function of reception time and material velocity associated with the material; and
at least one of storing the averaged compensated attenuation values in a memory or displaying the averaged compensated attenuation values on a display, wherein the averaged compensated attenuation values are determined by peaks in a compensated slowness-time attenuation (STA) map corresponding to peaks in a slowness-time coherency (STC) map, wherein each time, slowness point value in the STA map corresponds to a time, slowness point in the STC map, and wherein the STA map comprises the averaged compensated attenuation values.
2. The method of claim 1 , wherein the material velocity comprises slowness.
3. The method of claim 1 , wherein the averaged compensated attenuation values vary as a function of at least one of a borehole casing attenuation, an attenuation of an adhesive bonded to a borehole casing, and an attenuation of the geological formation.
4. The method of claim 1 , further including:
calculating the STC map values as a function of the reception time and the material velocity.
5. The method of claim 1 , further including:
compensating the averaged compensated attenuation values using a second set of multiple signals received by the multiple receivers from a second transmitted signal.
6. The method of claim 1 , further comprising:
receiving the first set of multiple signals with the multiple receivers.
7. The method of claim 1 , further comprising:
storing the STC map values calculated as a function of the material velocity in the memory.
8. A method, including:
displaying averaged compensated attenuation values associated with multiple signals received by multiple receivers along multiple paths between the multiple receivers from at least one transmitted signal as a function of reception time and material velocity on a display, wherein the averaged compensated attenuation values are determined by peaks in a compensated slowness-time attenuation (STA) map corresponding to peaks in a slowness-time coherency (STC) map, wherein each time, slowness point value in the STA map corresponds to a time, slowness point in the STC map, and wherein the STA map comprises the averaged compensated attenuation values.
9. The method of claim 8 , further including:
determining a compensated response value as a function of a response between two of the receivers selected from the multiple receivers.
10. The method of claim 9 , further including:
assigning a plurality of colors to selected groups of the averaged compensated attenuation values.
11. The method of claim 8 , wherein the averaged compensated attenuation values are a function of a ratio of responses associated with the multiple receivers.
12. The method of claim 8 , further including:
determining the averaged compensated attenuation values using a one-to-one correspondence with the STC map values.
13. An article including a machine-accessible medium having associated information, wherein the information, when accessed, results in a machine performing:
initiating at least one transmitted signal into material comprising a geologic formation; and
storing averaged compensated attenuation values associated with multiple signals received by multiple receivers along multiple paths between the multiple receivers from the at least one transmitted signal in a memory as a function of reception time and material velocity associated with the material, wherein the averaged compensated attenuation values are determined by peaks in a compensated slowness-time attenuation (STA) map corresponding to peaks in a slowness-time coherency (STC) map, wherein each time, slowness point value in the STA map corresponds to a time, slowness point in the STC map, and wherein the STA map comprises the averaged compensated attenuation values.
14. The article of claim 13 , wherein the information, when accessed
results in the machine performing:
displaying the averaged compensated attenuation values as at least a portion of the STA.
15. The article of claim 14 , wherein the information, when accessed, results in the machine performing:
identifying at least one material phase by grouping the averaged compensated attenuation values in the STA map.
16. The article of claim 13 , wherein units of the averaged compensated attenuation values are selected from one of inverse length and inverse time.
17. An apparatus, including:
a first downhole transducer to transmit a first transmitted signal;
a second downhole transducer to transmit a second transmitted signal; and
a memory to store averaged compensated attenuation values associated with a first set of multiple signals received by multiple receivers along multiple paths between the multiple receivers and associated with the first transmitted signal, and a second set of multiple signals received by the multiple receivers and associated with the second transmitted signal, as a function of reception time and material velocity, wherein the attenuation values are determined by peaks in a compensated slowness-time attenuation (STA) map corresponding to peaks in a slowness-time coherency (STC) map, wherein each time, slowness point value in the STA map corresponds to a time, slowness point in the STC map, and wherein the STA map comprises the averaged compensated attenuation values.
18. The apparatus of claim 17 , further including:
a first pulse amplifier coupled to a first transmitter coupled to the first transducer; and
a second pulse amplifier coupled to a second transmitter coupled to the second transducer.
19. The apparatus of claim 17 , further including:
a processor to initiate transmission of the first transmitted signal and the second transmitted signal as a function of a distance along a longitudinal axis of a borehole.
20. The apparatus of claim 17 , wherein the material velocity comprises slowness.
21. A system, including:
a memory to store averaged compensated attenuation values associated with a first set of multiple signals received by multiple receivers along multiple paths between the multiple receivers and associated with a first transmitted signal, and a second set of multiple signals received by the multiple receivers and associated with a second transmitted signal;
a processor to calculate the averaged compensated attenuation values; and
a display to display the averaged compensated attenuation values as a function of reception time and material velocity, wherein the attenuation values are determined by peaks in a compensated slowness-time attenuation (STA) map corresponding to peaks in a slowness-time coherency (STC) map, wherein each time, slowness point value in the STA map corresponds to a time, slowness point in the STC map, and wherein the STA map comprises the averaged compensated attenuation values.
22. The system of claim 21 , wherein the processor is to calculate the averaged compensated attenuation values as part of a two-dimensional matrix forming the STA map.
23. The system of claim 21 , wherein the display is to display the STC map.