Estimation of organic facies using ensemble methods in comparison with conventional intelligent approaches: a case study of the South Pars Gas Field, Persian Gulf, Iran

Reza Farzi, Vahid Bolandi
2016 Modeling Earth Systems and Environment  
Permian-Triassic deposited Dalan-Kangan carbonates in the South Pars Field are the host of the world's largest gas field in which, the Silurian shales might have had triggered the majority of the accumulated gas. Although it is believed that Dalan-Kangan has contribution in gas expulsion. One of the most important factors manipulating the source potential evaluation is considered to be total organic carbon (TOC). Since no TOC no source rock will be found in the area. Consequently in present
more » ... stigation TOC were utilized as a tool to evaluate the organic facies in combination with the intelligent methods. Current study implements ensemble algorithms as a new method in geoscience data appraisal in comparison with conventional intelligent systems. First of all, we applied fuzzy inference system (FIS) and neural network (NN) as traditional intelligent methods and LSBoost (LSB) and Bagging (BG) as ensemble algorithms to estimating the TOC from well log data. In the next step, Savitzky-Golay filter has been exploited for the data smoothing in order to galvanize regression and classification accuracy. Then, organic facies class membership was taken out by cluster analysis of the synthetized TOC values. In the last place, organic facies class membership were predicted using AdaBoost (AB), LogitBoost (LB), GentleBoost (GB) and Bagging (BG) as ensemble algorithms versus FIS and NN as being conventional intelligent systems directly from petrophysical well log data. Experimental results depict that ensemble methods outperform the common intelligent methods in term of regression and classification concepts. Also, Dalan-Kangan contribution in gas expulsion has been proved by detection of high organic rich interval (parts of k3 unit in Upper Dalan) in the field of study.
doi:10.1007/s40808-016-0165-z fatcat:45hh55eg3narjkelmplaswvfyq