Depth Seismic Shift To Match Well Markers

[gor...@multi-physics.com]

Hello!

 

I’m trying to determine the optimum shift on angle stacks in depth domain to get the best possible match between a seismic horizon and the corresponding well markers. There are four wells and each well has a different shift needed for the well marker to match the horizon. There is a high level of anisotropy in the area, which I think is why there is a mismatch I’m experiencing.

 

Is there an option in OpendTect that can help? Any suggestions/advice will be greatly appreciated.

 

Gorka Garcia Leiceaga, gor...@multi-physics.com

Senior Geophysicist

Multi-Physics Technologies

Tel: +1 713 561 3831; Cell: +1 832 273 3966

 

[Paul de Groot]

Hi Gorka,

As I do not quite understand what you want to achieve, I describe several options:

1. Align different angle stacks. Use "Match delta" and "Delta resample" attributes to get all events aligned horizontally. Optionally apply a horizontal median filter on the Match delta volume (Volume statistics attribute) to remove outliers before applying the shifts in Delta resample.
2. Apply a bulk shift to align the angle stack to the average of the mismatch error (Reference Shift attribute).
3. Modify the velocity curve that is used in the well tie. In the Well tie module, toggle the pick icon on and pick pairs of events (None, Peak, Trough, Peak or Trough, Zero crossing) on synthetic and real seismic traces to align these pairs. If you pick one pair, you apply a bulk shift. More than 1 pair means the velocity curve is stretched and squeezed.
4. Leave the data "AS IS" and solve the alignment problem in the final depth maps. (Horizon mathematics: create an error grid and add this to the mapped horizon).

I hope one of these solutions proves helpful.

Best regards,

Paul.

--

Paul de Groot

Special Adviser

-----------------------------------------------------------------------------------------------------------------------   dGB Earth Sciences
Phone: +31 53 4315155 E-mail: paul.d...@dgbes.com Internet: dgbes.com

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[gor...@multi-physics.com]

Hi Paul,

 

Thank you for your response.

 

I generated a fullstack and angle stack from time domain offset gathers/interval velocities and converted the stacks to depth. I also converted a time horizon to depth using the same interval velocity field. When I compare the well markers with the depth horizon on the depth stacks, there is a mismatch. The mismatch varies by a small amount at each of the wells I’m using, so simply shifting the seismic will not give me the match at all wells that I’m looking for.

 

I believe the well markers are the ground, so shifting the seismic seems like the only option.

 

If I were working in the time domain, I would know what to do since my entire career has been working with time data. Now that there are tools to predict rock and petrophysical properties in depth (i.e. machine learning), I was looking for feedback to see what is the best way to proceed.

 

I appreciate your email and the suggestions you made.

 

Thank you again and I hope all is well.

 

Gorka

 

 

 

From: Paul de Groot <paul.d...@dgbes.com>
Sent: Saturday, February 7, 2026 9:24 PM
To: us...@opendtect.org
Subject: Re: [OpendTect_Users] Depth Seismic Shift To Match Well Markers

 

Hi Gorka,

 

As I do not quite understand what you want to achieve, I describe several options:

1. Align different angle stacks. Use "Match delta" and "Delta resample" attributes to get all events aligned horizontally. Optionally apply a horizontal median filter on the Match delta volume (Volume statistics attribute) to remove outliers before applying the shifts in Delta resample.
2. Apply a bulk shift to align the angle stack to the average of the mismatch error (Reference Shift attribute).
3. Modify the velocity curve that is used in the well tie. In the Well tie module, toggle the pick icon on and pick pairs of events (None, Peak, Trough, Peak or Trough, Zero crossing) on synthetic and real seismic traces to align these pairs. If you pick one pair, you apply a bulk shift. More than 1 pair means the velocity curve is stretched and squeezed.
4. Leave the data "AS IS" and solve the alignment problem in the final depth maps. (Horizon mathematics: create an error grid and add this to the mapped horizon).

I hope one of these solutions proves helpful.

 

Best regards,

 

Paul.

--

Paul de Groot

Special Adviser

-----------------------------------------------------------------------------------------------------------------------   dGB Earth Sciences
Phone: +31 53 4315155 E-mail: paul.d...@dgbes.com Internet: dgbes.com

----------------------------------------------------------------------------------------------------------------------- 

 

On Thu, Feb 5, 2026 at 3:48 AM <gor...@multi-physics.com> wrote:

Hello!

 

I’m trying to determine the optimum shift on angle stacks in depth domain to get the best possible match between a seismic horizon and the corresponding well markers. There are four wells and each well has a different shift needed for the well marker to match the horizon. There is a high level of anisotropy in the area, which I think is why there is a mismatch I’m experiencing.

 

Is there an option in OpendTect that can help? Any suggestions/advice will be greatly appreciated.

 

Gorka Garcia Leiceaga, gor...@multi-physics.com

Senior Geophysicist

Multi-Physics Technologies

Tel: +1 713 561 3831; Cell: +1 832 273 3966

 

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[Tacjana Litwinska-Kemperink]

Hallo Gorka,

 

As a non-expert OpendTect user, I would like to share a few comments and questions from my point of view.

 

• Is there also a mismatch between the seismic horizon and the corresponding well markers on time-migrated data?
   
• How do other horizons and markers above and below the horizon in question behave? Is the mismatch consistent and linear with time/depth, or does it vary?
   
• You mention that “the mismatch varies by a small amount at each of the wells” — could you please clarify what is meant by a small amount
   
• What well data are used for the calibration: checkshots, VSP, sonic logs, or a combination of these?
   
• You mentioned a high level of anisotropy, which is obviously a very important factor.
   
  • Is it possible to relate this anisotropy to a specific geological formation (e.g., chalk, anhydrite, salt, etc.)?

Depending on the answers to these questions, different options and workflows available in OpendTect could be considered as mentioned by Paul.

In my opinion, shifting the seismic would not be the best solution.

 

Best regards,

 

Tacjana

 

Op 09-02-2026 05:43 CET schreef gor...@multi-physics.com:

To view this discussion visit https://groups.google.com/a/opendtect.org/d/msgid/users/004a01dc997e%24a7357620%24f5a06260%24%40multi-physics.com.

 

--------------------------------------------
SIC!
Seismic Interpretation & Consulting
Dr. Tacjana Litwinska-Kemperink
Sportlaan 43
7576 WT Oldenzaal
Tel.:+ 31 (0)541 523306

www.linkedin.com/in/tacjana-litwinska-kemperink-00279a51

 

 

 

[Friso Brouwer]

Hello Gorka,

Depending on the age and data of your wells and the consistency of the geologist/petrophysicist picking, the well tops itself may have a positioning error/uncertainty. 

Assuming the well tops are correctly positioned, this paper describes an approach you could use to decrease (but not eliminate) the mismatch: https://pubs.geoscienceworld.org/seg/interpretation/article-standard/doi/10.1190/int-2025-0025/725277/A-technique-for-matching-seismic-data-in-depth. I think you could use OpendTect, using some tricks, to implement a correction like that.

If you want precise matches you can use a similar approach, but you need to create a velocity field that is allowed to be laterally variant.

Cheers,

Friso Brouwer

Geophysical Consultant

I^3 GEO LLC

To view this discussion visit https://groups.google.com/a/opendtect.org/d/msgid/users/004a01dc997e%24a7357620%24f5a06260%24%40multi-physics.com.

[gor...@multi-physics.com]

Hi Friso,

 

Thanks for the suggestion. Log data is very limited; no density logs, and transit logs that I need to convert to sonic, which is something I’ve never had to do. This is why I chose to work in depth instead of time.

 

Cheers,

Gorka

To view this discussion visit https://groups.google.com/a/opendtect.org/d/msgid/users/CA%2BA_U%3DqFAXTuhNnWhjcDtKrPDpP9dnnBnJsKtpnaNBxCxkNs2A%40mail.gmail.com.

[gor...@multi-physics.com]

Hello, Tacjana,

 

Thanks for your response. I’ve answered your questions below in red.

 

From: 'Tacjana Litwinska-Kemperink' via OpendTect Users <us...@opendtect.org>
Sent: Monday, February 9, 2026 5:08 AM
To: us...@opendtect.org
Subject: RE: [OpendTect_Users] Depth Seismic Shift To Match Well Markers

 

Hallo Gorka,

 

As a non-expert OpendTect user, I would like to share a few comments and questions from my point of view.

 

• Is there also a mismatch between the seismic horizon and the corresponding well markers on time-migrated data?

I was not provided depth/time relationships and have no density logs. I do have two sonic transit time logs, but those need further processing for me to use. This is why I’m working in depth domain.

• How do other horizons and markers above and below the horizon in question behave? Is the mismatch consistent and linear with time/depth, or does it vary?

I only have one horizon and the corresponding well markers

• You mention that “the mismatch varies by a small amount at each of the wells” — could you please clarify what is meant by a small amount

Between 290 to 320 meters shift required at each of the wells

• What well data are used for the calibration: checkshots, VSP, sonic logs, or a combination of these?

Working in depth domain

• You mentioned a high level of anisotropy, which is obviously a very important factor.

• Is it possible to relate this anisotropy to a specific geological formation (e.g., chalk, anhydrite, salt, etc.)?

Yes, the formation of interest is highly fractured volcanic tuff, and the target hydrocarbons are the fractured zones.

To view this discussion visit https://groups.google.com/a/opendtect.org/d/msgid/users/468745127.598453.1770635287706%40kpc.webmail.kpnmail.nl.