Abstract:

The reservoir ofXishanyao Formation（J₂x） in Niuquanhu Oilfield is characterized by lowporosity, lowpermeability, lowpressure and strongheterogeneity, soreservoir prediction is particularlyimportant. Through contrast and analysis of well logs, natural gamma ray curve and sonic log curve were selected to build up a sonic-dimensional pseudo-acoustic curve, and broadband constrained simulated annealing nonlinear global optimization inversion method was applied to carry out reservoir prediction. Through comparing three degrees of constraint of logging data（① 10% seismic and 90% logging, ② 30% seismic and 70% logging, ③ 50% seismic and 50% logging）, it is found that the inversion result from using 10% seismic and 90% logging is of the highest accuracy. It shows that using seismic inversion technique based on model can obtain high-resolution impedance information, and effectively distinguish reservoir fromnon-reservoir. According to the comparison between predicted and actual drilling results, the error causes and problems were analyzed.

Key words: faults connected with source rock, ratio between sandstone and stratum, cap rock, positive stactures, the firstmember ofDongyingFormation, Nanpu Depression