Paleogene Caprock Characteristics and its Influence on petroleum systems of Damintun Sag in Liaohe Depression Basin
Meng Weigong
1. Exploration Environment and Resources School of Southwest Petroleum Institute, Chengdu, Sichuan 610500
2. Liaohe Oilfield Branch Company of PetroChina, Panjin, Liaoning 124010
Damintun sag in Liaohe depression basin is a famous high pour-point oil production basement. This paper discusses the important of the two sets of regional mudstone caprock to the accumulation of oil and gas distribution by analyzing the distribution features and sealing property of caprock. This study on the overpressure of fluid show that there are two overpressure sealing system which are corresponding to the two set of caprock. The overpressure sealing system played an important role oil and gas migration and accumulation. This sag can be divided into two petroleum system, the high wax petroleum system and normal one. These two regional systems seal the high wax system and the normal system respectively. It is just because that Damintun sag had sealing systems, the sag has abundant oil and gas accumulations.
