Identifying productive zones of the Sarvak formation by integrating outputs of different classification methods

Pedram Masoudi (1) , Behzad Tokhmechi (1) , Alireza Bashari (2) , Majid Ansari Jafari (1)

1 School of Mining, Petroleum and Geophysics Engineering
2 Iranian Society of Petroleum Geology

Sarvak formation is the second major carbonate reservoir in Iran. There are several geological, petrophysical and geophysical investigations which have been carried out on this important reservoir. In this work, Sarvak is studied to find productive zones. At first, four different methods were used to identify producing intervals from well log data and well test results. Then, final zoning is generated by integrating outputs of these four methods. One of them is the conventional cutoff based method; the other three methods are based on flow equation, Bayesian and fuzzy theories. Thereafter, by considering the classification correctness rate of each classifier in each well and technique of majority voting, a unique zoning for Sarvak formation is presented. Based on the final zoning, the whole Sarvak interval is divided into seven zones. Three of them are classified as oil producing zones, two of them cannot be classified as conventionally producing zones, and the remaining two are water producing. Zone number 2 not only has the highest production rate, but also is the most homogeneous zone among the productive zones. The novelty of this research is using well test results in defining productive classes, which improves the certainty of classification in comparison with previous works that were based on core analysis and log data.

Mots clés: Sarvak formation; carbonate reservoir; productivity; pay zone; zoning; data fusion

Domaines: Géologie appliquée

Pedram Masoudi, Behzad Tokhmechi, Alireza Bashari, Majid Ansari Jafari. Identifying productive zones of the Sarvak formation by integrating outputs of different classification methods. Journal of Geophysics and Engineering, 2012, 9 (1), pp.282 - 290. ⟨10.1088/1742-2132/9/3/282⟩. ⟨insu-01382411⟩