Abstract:

The deposits of sudden event gravity flowwhich are not only rigid and compact but also have characteristics of thin thickness and complex sedimentation type are generally mingled with normal deposits, which makes the recognition of lithology and fluid property very difficult with conventional log data. According to core observation, it is considered that the first member of Liushagang Formation in W oilfield which is the important oil-bearing series developed large amount of various types of gravity flowdeposits. Based on the analysis of depositional characteristics, the methods of crossplot and logging curve shape are proposed to distinguish effectively the the event gravity flow deposits fromthe normal deposits by using the high precision gamma ray and density curve of subaerial core scanning. Finally the oil possibility and physical property of the gravity flowdeposits are evaluated, and the result shows that distal turbidite is the favorable exploration and development target and two possible oil-bearing turbidite sand bodies are pointed out, which provides basis and supports for further evaluation and tapping the potential of the oilfield.

Key words: dual &gamma, model； simulated annealing； pre-stack multi-wave inversion； interval quartation； Sulige Gas Field