Formation 2 is the main contributor to hydrocarbon production in the Gulf of Thailand. Nine key lithofacies were deposited in fluvial and tide-dominated deltaic environments. Two methods of electrofacies classification were used to estimate rock types in non-cored wells, including Artificial-Neural Networks and K-means clustering. For mapping purposes, lithofacies are combined into four lithologies: 1) coal, 2) claystone, 3) heterolithic sandstone, and 4) sandstone. Using ANNs classification with an overall accuracy of 85%, lithology logs were estimated to establish a sequence-stratigraphic framework and to map reservoir properties.

Formation 2 stratigraphic framework consists of five third-order cycles named units 2A-E. The moderate eustatic sea-level rise approximately 19 Ma resulted in a variety of depositional environments, facies distributions, and reservoir properties. Units 2A-C represent a continuous transgression and landward shift of facies. The top of unit 2C possibly indicates the maximum landward extent of shoreline. Unit 2D records a major regression resulting from a glacio-eustatic sea-level fall and tectonic uplift in this region.

Three-dimensional models illustrate the distribution of lithology, porosity, and permeability of fluvial and tide-dominated deltaic deposits. Sandstone percentage and reservoir quality relates to the regressive cycle, unit 2D, while transgressive cycles 2A-C exhibit lower sandstone content and reservoir quality.


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  1. Carney, S., I. A.Aziz, W.Martins, A.Low, and J.Kennedy
    , 2010, Reservoir characterization of the Mio-Pliocene reservoirs of block PM301 in the North Malay Basin: Society of Petroleum Engineers, doi:10.2118/131017‑MS.
    https://doi.org/10.2118/131017-MS [Google Scholar]
  2. Catuneanu, O., W. E.Galloway, C. G. S. T. C.Kendall, A. D.Miall, H. W.Posamentier, A.Strasser, and M. E.Tucker
    , 2011, Sequence Stratigraphy, Methodology and Nomenclature: Newsletters on Stratigraphy, v. 44, no. 3, p. 173–245.
    [Google Scholar]
  3. Leo, C. T. A. M.
    , 1997, Exploration in the Gulf of Thailand in deltaic reservoirs, Related to the Bongkot Field: Geological Society, London, Special Publications, v. 126, p. 77–87.
    [Google Scholar]
  4. Madon, M. B., J. S.Yang, P.Abolins, M. Y.Redzuan, and B. Z.Azmi
    , 2006, Petroleum System of the Northern Malay Basin: Geological Society Malaysian Bulletin, v. 49, p. 125–134.
    [Google Scholar]
  5. Petchdong, S.
    , 2008, Controls on reservoir quality in a depositional framework of Formation 2, South Bongkot Area, North Malay Basin, Gulf of Thailand: Bulletin of Earth Sciences of Thailand, v. 3, p. 5–8.
    [Google Scholar]
  6. Polachan, S.
    , 1986, Oil Potential in the Gulf of Thailand: Offshore Technology Conference, p. 255–259.
    [Google Scholar]
  7. Watcharanantakul, R., and C.K.Morley
    , 2000, Syn-rift and post-rift modeling of the Pattani Basin, Thailand, Evidence for a ramp-flat detachment: Marine and Petroleum Geology, v. 17, no. 8, p. 937–958.
    [Google Scholar]

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