MINERALOGICAL CHARACTERISTICS OF ZEOLITE MINERALS AND THEIR BEARINGS TO THE RESERVOIR BEDS IN THE KARMAY OIL FIELD

Six types of zeolite minerals and a kind of albite associated with zeolite evolution have been recognized in the reservoir beds in the Karamay oil field. On the basis of mineralogical characteristics and distribution, the author contends that zeolite and zeolitic associations are longitudinally zoned and closely related to burial diagenesis. The analcime and analcime+heulandite zones were formed during Stage B of early diagenesis; the heulandite+laumontite zone during Stage A of late diagenesis, and the laumontite+albite zone during Stages B to C of late diagenesis. Albitization and erosion of analcime contribute a lot to the reservoir quality. In addition, some superimposed phenomena in the heulandite zonation are also discussed in this paper.