Current off saturation in the Moxizhuang （莫西庄） Off Field in central Junggar （准噶尔） basin was evaluated by logging interpretation and measured on core samples, and the paleo-oil saturation in both the pay zone...Current off saturation in the Moxizhuang （莫西庄） Off Field in central Junggar （准噶尔） basin was evaluated by logging interpretation and measured on core samples, and the paleo-oil saturation in both the pay zones and water zones was investigated by grain-containing-oil inclusion （GOI） analysis. The pay zones in this field have low off saturation and display low resistivity and small contrast between pay zones and water zones, and are classified as low-porosity, low oil saturation, and low resistivity reservoirs. Both the current low oil-saturation pay zones and the water zones above 4 365 m have high GOI values （up to 38%）, suggesting high paieo-oil saturation. The significant difference between current oil saturation from both logging interpretation and core sample measurement and paleo-oil saturation indicated by GOI analysis suggests that this low off-saturation field evolved from a high off-saturation pool. Lateral re-migration and spill of formally trapped oil owing to changes in structural configuration since Neogene was the most plausible mechanism for off loss in the Moxizhuang Oil Field. The combined effects of differential accumulation in the charge phase and the differential re-migration and spill of accumulated oil in Neogene are responsible for the complicated correlation between residual oil saturation and porosity/permeability of the reservoir sandstones and the distribution of low oil-saturation pay zones and paieo-oil zones （current water zones）.展开更多
基金the National Natural Science Foundation of China (No. 40772089)973 Projects (No. 2005CB422105)Program for Changjiang Scholars and Innovative Research Team in the University (IRT0658).
文摘Current off saturation in the Moxizhuang （莫西庄） Off Field in central Junggar （准噶尔） basin was evaluated by logging interpretation and measured on core samples, and the paleo-oil saturation in both the pay zones and water zones was investigated by grain-containing-oil inclusion （GOI） analysis. The pay zones in this field have low off saturation and display low resistivity and small contrast between pay zones and water zones, and are classified as low-porosity, low oil saturation, and low resistivity reservoirs. Both the current low oil-saturation pay zones and the water zones above 4 365 m have high GOI values （up to 38%）, suggesting high paieo-oil saturation. The significant difference between current oil saturation from both logging interpretation and core sample measurement and paleo-oil saturation indicated by GOI analysis suggests that this low off-saturation field evolved from a high off-saturation pool. Lateral re-migration and spill of formally trapped oil owing to changes in structural configuration since Neogene was the most plausible mechanism for off loss in the Moxizhuang Oil Field. The combined effects of differential accumulation in the charge phase and the differential re-migration and spill of accumulated oil in Neogene are responsible for the complicated correlation between residual oil saturation and porosity/permeability of the reservoir sandstones and the distribution of low oil-saturation pay zones and paieo-oil zones （current water zones）.
