Abstract:

Reservoirs of the Jiamuhe Formation in 5th district,Karamay Oilfield,consist of igneous,sedimentary and metamorphic rocks with crevice-poredual medium.According to identification of facies based on volcanic me-chanism and the study of the speciality and behaviours of the reservoirs frommacrostructure and microstructure,the reservoirs can be divided into threegrades in the present paper.It is showed that the crevices play a dominantrole in improving the physical property of the reservoirs and increasing theyield of oil wells.