Abstract:

Proterozoic era of Damintun depression is the important oil and gas producing reservoir in Liaohe field, which mainly distributes in the west and north of the depression in step array in north trend ang east trend. Up to date，Jing’anbaobei oilfield, Ping’anbao oilfield，Anfutun oilfield have been established. Through geological study, Proterozoic is divided into two formations, i.e, Dahongyu Formation and Gaoyuzhang Formations which are further divided into 18 zones with 7 sedimentary cycles. The dominant reservoir rocks are carbonate and quartzite. The reservoir features are studied and summarized indicating three kinds of hydrocarbon storage spaces, which are fractures, pores, and cavities, and the high aperture fractures are the dominant storage spaces. It is found out that dolomite rock reservoir is the fractured reservoir, and quartzose reservoirs mainly are fractured reservoir and the secondary important reservoirs are crystalline pores, crystalline vuggy and crystalline fissures reservoir. Based on the logging data, oil and gas bearing reservoir identification and comprehensive evaluation are made, in addition, the analysis on the factors controlling the reservoir storage properties is done, and it is found out that reservoir hydrocarbon storage spaces are very complicated and highly heterogeneous, which are controlled by lithology, fault, karst, paleo-weathering.

Key words: Damintun depression, Proterozoic era, reservoirs, carbonate, quartzite