Reservoir identification and characterization through sequential horizon mapping and geostatistical analysis: a case study from the Gulf of Thailand

The integration of sequential horizon slicing, attribute extraction, seismic facies characteristics, and wireline information from a Gulf of Thailand dataset enabled reconstruction of the depositional sequence, identification of reservoir units, and the analysis of reservoir geometry within an approximately 50 ms thick interval of seismic data. The depositional environment was verified to be fluvio-deltaic, with potential reservoirs comprising channel sands, associated point bars, thin crevasse splays and thin sand bars. Channel geometries were measured for five main channels using width/thickness ratios and sinuosity. Areal distributions of porosity, net sand thickness, gas saturation and hydrocarbon pore meter were predicted through geostatistical modelling. Collocated cokriged maps revealed high porosity and high sand thickness trends to relate to the main channel geometries. Collocated cokriged predictions of gas saturation and HPM distributions showed four potential areas of hydrocarbon accumulations where sand channels terminating against fault planes formed dip closures in structural highs.