NFES Norwegian Formation Evaluation Society

NFES Norwegian Formation Evaluation Society
Predicting likely stratigraphy realizations from shallow logs with AI

Event Start Date / Time

12/07/2022 11:00 AM - 1:30 PM

Contact : [email protected]


Event Description

Let's close the year together - the last 2022 in-person NFES Monthly Meeting with Sergey Alyaev, senior research scientist with NORCE, takes place Wednesday 07 Dec in the Solastranden Gård!

Sergey will present how to achieve ”Predicting likely stratigraphy realizations from shallow logs with AI” – using a developed multi-modal probabilistic interpretation method which outputs several stratigraphic solutions, even predicting stratigraphy ahead!”

All members of the SPWLA and its local chapter Norwegian Formation Evaluation Society are welcome to attend this in-person and video conference … contact us for the link!

Event Link

https://www.linkedin.com/feed/update/urn:li:activity:7001154318435291136/

Event Presenter

Sergey Alyaev, NORCE Norwegian Research Centre

Abstract:
Geosteering of wells requires fast petrophysical and geological interpretation of logs, often forming non-unique inverse problems. We developed a multi-modal probabilistic interpretation method using a single evaluation of an artificial deep neural network (DNN) in milliseconds. A mixture density DNN is trained using the “multiple-trajectory-prediction” loss functions. It outputs several stratigraphic solutions and their probabilities and predictions of stratigraphy ahead of data. Thus, it yields an AI that learns the ability to match the logs and select likely geological scenarios from the training data.
The proposed approach is verified on a stratigraphic interpretation of gamma-ray and rate-of-penetration logs from drilling in an unconventional field. For a single chunk of data, the multi-modal predictor outputs several viable inverse solutions/predictions, providing more accurate and realistic solutions than a deterministic regression using a DNN. Applying this method sequentially (using the precious interpretations as starting points) allows tracking several likely stratigraphic realizations throughout a geosteering operation or until new data disconfirm them. Multi-solution tracking is vital for drilling operations where only a little, noisy, or low-quality data is available. It enables informed decisions from quantified geological uncertainties.

This presentation is based on the work produced in the Center for Research-based Innovation DigiWells (NFR SFI project no. 309589, https://DigiWells.no).

References:
1. Alyaev, S., & Elsheikh, A. H. (2022). Direct Multi-Modal Inversion of Geophysical Logs Using Deep Learning. Earth and Space Science, 9(9), e2021EA002186. https://doi.org/10.1029/2021EA002186
2. Alyaev, S., Ambrus, A., Jahani, N., & Elsheikh, A. H. (2022). Sequential Multi-Realization Probabilistic Interpretation of Well Logs and Geological Prediction by a Deep-Learning Method. In SPWLA 63rd Annual Logging Symposium. https://onepetro.org/SPWLAALS/proceedings-abstract/SPWLA22/5-SPWLA22/D051S022R001/487879


When
12/7/2022
Where
Solastranden Gård Nordsjøvegen 299 Sola 4053 NORWAY

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