Characteristics And Controlling Factors Of Carboniferous Volcanic Rock Reservoirs In Well Block 10,Jinlong

Volcanic oil and gas reservoirs have always been difficult for exploration and development at home and abroad.However,with the increasing demand for oil and gas resources all over the world,the exploration and development of oil and gas at home and abroad have continued to deepen,and volcanic oil and gas reservoirs have been discovered all over the world.The Carboniferous volcanic reservoirs in the Junggar Basin are mainly concentrated in the northwestern margin of the basin.The entire northwestern margin is a thrust nappe structure.So far,in the Junggar Basin volcanic rock reservoirs have been exploited for nearly 60 years,and the proven reserves of volcanic rocks are nearly 200 million tons.The proved rate of oil resources is less than 20%,indicating that the area still deserves further study.The controlled oil reserves of the Carboniferous reservoir in Jinlong 10 well area are reported to be 4117×104t,which is an important block for the production capacity of the Xinjiang oilfield from 2015 to 2016.Based on core,thin section,well logging,seismic and analysis and analysis data,the volcanic reservoir characteristics and reservoir development control factors in the Jinlong 10 well area were analyzed to obtain understanding: 1)The volcanic lithofacies are dominated by overflow and outburst phases,followed by It is a volcanic channel and intrusive phase.2)The reservoir space is mainly composed of dissolved pores and dissolved cracks.The porosity of the reservoir is 0.1% to 15.9% with an average of 3.6%,and the permeability is 0.01 mD to 32.90 mD,with an average of 0.038 mD.The reservoirs with higher porosity are mainly distributed within 200 m from the weathering crust,but at deeper depths There are still some reservoir properties;The pore throat structure has the characteristics of fine pore throat and poor separation,the average porosity is 7.7%,and the permeability is average.6.81 mD,the average volume of unsaturated pores is 22.53%,the average pressure is 3.51 MPa,the median radius is 0.19 mm,the maximum pore throat radius is 2.75 mm,and the average capillary radius is 0.70mm;3)The formation of wells with dissolved pores is identified.Control factors: volcanic eruption gap period(volcanic cycle),volcanic cycle back to the upper plagioclase and other minerals to analgeite,chlorite alterations,the formation of an unstable layer.Late Carboniferous tectonic movements resulted in the development of faults and fractures and the formation of unconformity surfaces.Atmospheric water distorted longitudinally and laterally along the fracture-crack and the unstable top layer of the cycle,forming a group of pore seams.At the end of Jurassic tectonic compression,fracture-fracture was formed again,and the reservoirs of the pores were divided and the reservoir space was basically shaped.Under the control of fracture cracks,palaeogeomorphology and the volcanic cycle interface,the pore-slot reservoirs show zonality in the longitudinal direction,and are laterally represented by the thin lenticular features of the paleo-slopes of ancient geomorphological highland reservoirs.The overall performance is shown by cracks.,Dissolved pores and dissolved joints constitute a "multi-storey building" complex reservoir.The geologic model of the pore-formed volcanic reservoirs provided is a valuable reference for the prediction of volcanic reservoirs and oil and gas exploration.