Characteristics Of Mesozoic Buried Igneous Hills Reservoirs In PL9-1 Area,Bohai Sea

In recent years,the research and exploration of igneous rock reservoir is more and more mature,igneous rock reservoir as an important reservoir type is gradually valued.The buried igneous hill reservoir of oilfield has been found in PL9-1 area,at present the research about buried igneous hill reservoir is not fully carried out.Based on igneous petrology and with casting section identification,X-ray diffraction,Scanning electron microscopy,Cathode luminescence,porosity and permeability test as experiments,the characteristics of rock type,reservoir space types,reservoir physical properties,diagenetic evolution of igneous rocks and diagenetic facies are studied,the control factors of influencing igneous reservoir are determined and the igneous rock reservoir types are divided.Finally,the reservoir evaluation system is established.The lithology in the PL9-1 area is mainly granitoid,syenitoid and a small amount of vein rocks.Its reservoir space type is mainly secondary and pore-fracture type.The reservoirs generally belong to the type of low porosity and low permeability,some of reservoirs form the types of moderate porosity and moderate permeability,or high porosity and high permeability because of fracture development.So the reservoir in the research divided into three types: fracture-secondary pore type,fracture type and micro pore-micro fracture type,then fracture-secondary pore type and fracture type are suitable for industrial production.Diagenetic stage in the research area is divided into the magmatic hydrothermal stage,weathering leaching stage and burial-diagenetic stage.The reservoirs in PL9-1 area have experienced the recrystallization,metasomatic dissolution,tectonics,weathering and dissolution,so diagenetic facies is divided into six types: higher porosity and higher permeability+ illite +fracture facies,high porosity and high permeability + kaolinite+ chlorite +fracture facies,moderate porosity and moderate permeability+ secondary quartz+ kaolinite+ facture dissolution facies,low porosity and low permeability + kaolinite+ illite+ calcite cement +dissolution facies,lower porosity+ secondary quartz+ illite+ mica +calcite cement+ dissolution facies,lowest porosity +illite +crystallization facies.The form of reservoirs mainly relies on magmatism,weathering and tectonism.In control of varieties of factors,the final shape of reservoirs is formed.The magmatic rock reservoirs in PL9-1 are influenced by magmatism and lithology,tectonics,weathering and diagenesis.According to the porosity and permeability datas,reservoir space types and diagenetic faicies,the research of igneous reservoir evaluation system is built.