Predicting Pyrite and Total Organic Carbon from Well Logs for Enhancing Shale Reservoir Interpretation

2012 ◽  
Author(s):  
James M. Witkowsky ◽  
James Elmer Galford ◽  
John Andrew Quirein ◽  
Jerome Allen Truax
Keyword(s):  
Organic Carbon ◽  
Total Organic Carbon ◽  
Well Logs ◽  
Shale Reservoir

scholarly journals Application of Various Machine Learning Techniques in Predicting Total Organic Carbon from Well Logs

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Osama Siddig ◽  
Ahmed Farid Ibrahim ◽  
Salaheldin Elkatatny
Keyword(s):  
Machine Learning ◽  
Organic Carbon ◽  
Total Organic Carbon ◽  
The Other ◽  
Well Logs ◽  
Machine Learning Techniques ◽  
Percentage Error ◽  
Average Error ◽  
Support Vector ◽  
Empirical Correlations

Unconventional resources have recently gained a lot of attention, and as a consequence, there has been an increase in research interest in predicting total organic carbon (TOC) as a crucial quality indicator. TOC is commonly measured experimentally; however, due to sampling restrictions, obtaining continuous data on TOC is difficult. Therefore, different empirical correlations for TOC have been presented. However, there are concerns about the generalization and accuracy of these correlations. In this paper, different machine learning (ML) techniques were utilized to develop models that predict TOC from well logs, including formation resistivity (FR), spontaneous potential (SP), sonic transit time (Δt), bulk density (RHOB), neutron porosity (CNP), gamma ray (GR), and spectrum logs of thorium (Th), uranium (Ur), and potassium (K). Over 1250 data points from the Devonian Duvernay shale were utilized to create and validate the model. These datasets were obtained from three wells; the first was used to train the models, while the data sets from the other two wells were utilized to test and validate them. Support vector machine (SVM), random forest (RF), and decision tree (DT) were the ML approaches tested, and their predictions were contrasted with three empirical correlations. Various AI methods’ parameters were tested to assure the best possible accuracy in terms of correlation coefficient (R) and average absolute percentage error (AAPE) between the actual and predicted TOC. The three ML methods yielded good matches; however, the RF-based model has the best performance. The RF model was able to predict the TOC for the different datasets with R values range between 0.93 and 0.99 and AAPE values less than 14%. In terms of average error, the ML-based models outperformed the other three empirical correlations. This study shows the capability and robustness of ML models to predict the total organic carbon from readily available logging data without the need for core analysis or additional well interventions.

Determination of the total organic carbon (TOC) based on conventional well logs using artificial neural network

2017 ◽  
Vol 179 ◽  
pp. 72-80 ◽  
Author(s):  
Ahmed Abdulhamid A. Mahmoud ◽  
Salaheldin Elkatatny ◽  
Mohamed Mahmoud ◽  
Mohamed Abouelresh ◽  
Abdulazeez Abdulraheem ◽  
...  
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Organic Carbon ◽  
Total Organic Carbon ◽  
Well Logs ◽  
Artificial Neural

DETERMINATION FROM WELL LOGS OF THE TOTAL ORGANIC CARBON CONTENT IN POTENTIAL SOURCE ROCKS

1994 ◽  
Vol 34 (1) ◽  
pp. 307
Author(s):  
J.L. Lin ◽  
H.A. Salisch
Keyword(s):  
Organic Carbon ◽  
Total Organic Carbon ◽  
Source Rocks ◽  
Well Logs ◽  
Organic Carbon Content ◽  
Well Log ◽  
Single Model ◽  
Geochemical Properties ◽  
Comparison Of The Results ◽  
Immature Source Rock

This paper discusses, in some detail, the log responses to total organic carbon (TOC) in the Upper and Middle Velkerri Formation in an area of the McArthur Basin, Northern Territory, Australia. The Formation Density log was found to be superior to other standard well logs in assessing values of TOC in the area studied. A theoretical model was used to estimate TOC from the Formation Density log. The model was established and its applicability was verified by comparison with other models. Based on geochemical properties the Upper and Middle Velkerri Formation is classified into three categories: nonsource rocks, mature source rocks and immature source rock. They show significant differences in the well log responses, and different models had to be established for the three categories to determine the TOC content from well logs. Comparison of the results of using a different model for each category instead of a single model to cover the three categories shows that the former approach gives more meaningful answers.

scholarly journals Evaluation of the Total Organic Carbon (TOC) Using Different Artificial Intelligence Techniques

2019 ◽  
Vol 11 (20) ◽  
pp. 5643 ◽  
Author(s):  
Ahmed Abdulhamid Mahmoud ◽  
Salaheldin Elkatatny ◽  
Abdulwahab Z. Ali ◽  
Mohamed Abouelresh ◽  
Abdulazeez Abdulraheem
Keyword(s):  
Artificial Intelligence ◽  
Organic Carbon ◽  
Total Organic Carbon ◽  
Well Logs ◽  
Support Vector ◽  
Validation Data ◽  
Fuzzy Interference System ◽  
Interference System ◽  
Unseen Data ◽  
Devonian Shale

Total organic carbon (TOC) is an essential parameter used in unconventional shale resources evaluation. Current methods that are used for TOC estimation are based, either on conducting time-consuming laboratory experiments, or on using empirical correlations developed for specific formations. In this study, four artificial intelligence (AI) models were developed to estimate the TOC using conventional well logs of deep resistivity, gamma-ray, sonic transit time, and bulk density. These models were developed based on the Takagi-Sugeno-Kang fuzzy interference system (TSK-FIS), Mamdani fuzzy interference system (M-FIS), functional neural network (FNN), and support vector machine (SVM). Over 800 data points of the conventional well logs and core data collected from Barnett shale were used to train and test the AI models. The optimized AI models were validated using unseen data from Devonian shale. The developed AI models showed accurate predictability of TOC in both Barnett and Devonian shale. FNN model overperformed others in estimating TOC for the validation data with average absolute percentage error (AAPE) and correlation coefficient (R) of 12.02%, and 0.879, respectively, followed by M-FIS and SVM, while TSK-FIS model showed the lowest predictability of TOC, with AAPE of 15.62% and R of 0.832. All AI models overperformed Wang models, which have recently developed to evaluate the TOC for Devonian formation.

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