Reservoir property differences and main controlling factors in deep-water gas field,Pearl River Mouth Basin
Two adjacent gas fields have different reservoir properties in the same deep-water basin-floor fan in Liwan gas area of Pearl River Mouth Basin.To clear the main controlling factors,we comparatively analyzed rock composition,microscopic pore structure,and macroscopic physical properties of the two gas fields based on injecting thin sections,SEM observations,physical property,and mercury injection test,and then explored the impact of sedimentation and diagenesis on reservoir qualities.The results showed that:1)The reservoir quality is generally controlled by sedimentation.A gas field in the fan end is characterized by a fine grain size and is well-sorted;however;B gas field in the fan root is characterized by a coarser grain size,worse-sorted,and intergranular muddy matrix;2)Differentiated diagenesis caused by different burial depths is the main controlling factor of reservoir qualities.Under the action of deep burial and strong compaction,intergranular argillaceous matrixes are easy to extrude and deform in the reservoir with high plastic component content,reducing the reservoir's primary pore volume.At the same time,the illites and illite-smectite mixed-layers in clay minerals are mostly in the form of strands/silk sheets and fill the intergranular and secondary pore spaces,significantly reducing reservoir permeability.The study can be used for reference in oil-gas exploration and production in deep-water basin-floor fans.
reservoir quality differencediagenesisdeep-water basin-floor fanPearl River Mouth Basin
万方数据
维普
