CHARACTERISTICS OF CARBONIFEROUS VOLCANIC RESERVOIRS IN THE6th AND7th AREAS OF KARAMAY OIL FIELD
Characteristics of lithology,physical and pore structure of the Carboniferous volcanic rocks in the 6th and the 7th districts of Karamay oil field are studied through observation and analysis of drilling cores of 665.56meters long from 32drilling wells,470thin sections,666physical analysis samples and 82drilling wells logging data.It is showed that burial depth of layers,lithology and fractures are 3main factors influencing the reservoirs in this area,and the most favorable reservoir is located in the south of the 6district and the middle of the 7district.Pyroclastic rock and sedimentary rock are the main rock types in the area and the major lithology of volcanic rock reservoir is breccias lava and basalt characteristic of low porosity and permeability.Reservoir space is dominated by stoma,intercrystal pore,vug and pre-existing fractures.The favorable reservoir mainly distributes in the south and northwest of 6district and in the middle of 7district.