Abstract:Based on the summary of the basic conditions of hydrocarbon reservoir formation such as source rock, reservoir and trap in the Wuyunting area, this study systematically analyzes the characteristics and sources of oil and gas, pressure distribution and fault sealing, the history of hydrocarbon charging and accumulation, the process of hydrocarbon migration and accumulation, to establish the reservoir forming model of Wuyunting condensate gas field. Research shows that many factors jointly control formation of the Wuyunting condensate gas field, such as the strong hydrocarbon- generating capacity of widely distributed coal- measure source rocks in the Wuyunting sag and source rocks in the Ningbo 27 main sag, faults and sandstone pinch- out line controlled large- scale structural lithologic composite traps, the development of high- quality delta sedimentary reservoirs, favorable fault sand configuration and good caprock quality. The reservoir forming assemblage in the middle and lower part of Pinghu Formation of Wuyunting oil and gas field has the characteristics of “hydrocarbon supply from coal measure source rock in Wuyunting sag and continuous weak overpressure charging within the source rock”; the upper and middle part of the reservoir forming assemblage has the characteristics of “double source hydrocarbon supply from Wuyunting sag and Ningbo 27 sag, and continuous strong lateral charging”. The Early bidirectional source crude oil mixed with late large- scale lateral source high- mature gas to form condensate gas reservoir. Wuyunting oil and gas field is generally characterized by “early oil and late gas, multi- stage reservoir formation and continuous filling”, and a reservoir formation mode of “multi- source continuous strong filling and sand breaking combined control” is established. The Wuyunting oil and gas field generally has the characteristics of “early oil and late gas, multi- stage accumulation and continuous charging”, so the accumulation model of “multi- source continuous strong charging, fault- sand joint control” has been established.