Application of GeoEast interpretation system in hydrate saturation prediction
LIU Pengqi1,2, QIN Min3, LIU Kang3, MAO Shuang3, BIAN Huapeng3, XIN Fubing3
1. Sanya Institute of South China Sea Geology, Guangzhou Marine Geological Survey, Sanya, Hainan 572025, China; 2. Academy of South China Sea Geological Science, China Geological Survey, Sanya, Hainan 572025, China; 3. PetroChina Liaohe Oilfield Company, Panjin, Liaoning 124010, China
Abstract：The study area is located in the deep-water area of the outer continental slope at the northwest continental margin of some sea area. The three-dimensional (3D) seismic data and sampled seabed sediment data of this area are available, but the logging data of target horizon is lacking, and hydrate saturation in this area has not been predicted yet. In this study, an evaluation method of hydrate saturation is developed by the mere use of wave impedance data. According to the geological conditions of the study area, the equation to calculate saturation is established on the basis of the magnifying coefficient method of wave impedance, and the hydrate saturation of the target reservoir in the area is quantitatively calculated. With Wood's equation and the Archie equation, the magnifying coefficient formula of wave impedance suitable for the study area is derived. The compressional-wave (P-wave) impedance data are converted into the magnifying coefficient data of wave impedance by the GeoEast interpretation system to calculate the hydrate saturation in the study area. The results show that this method is effective in predicting the hydrate saturation on the shallow surface of the seabed under the condition of stable deep-water sedimentation. Compared with the traditional velocity method, it can effectively eliminate the influence of factors such as lithology, burial depth, and porosity on the calculation results of saturation. This method is of the reference significance to the prediction of natural gas hydrate saturation in areas with similar geological conditions to those of the study area.
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