关键词: 溶洞发育带, 地球物理识别模式, 非均质性, 储层预测, 碳酸盐岩缝洞型储层, 奥陶系, 塔河油田

Abstract:

The Ordovician fractured-vuggy carbonate reservoirs in Tahe oilfield have a burial depth of more than 5 300 m.Their matrix has no storage capacity and their reservoir spaces are dominated by fractures and vugs,which control the accumulation of oil and gas.The reservoirs have a strong heterogeneity both vertically and horizontally.The reservoir prediction is very difficult due to its low seismic SNR and poor resolution.Predicting and locating the highly fractured-vuggy zones in the Ordovician thus becomes the key factor for increasing of the growth of reserves and production in Tahe oilfield.Based on the strudy of genetic mechanism of the reservoirs,a genetic prediction mode is established for the fractured-vuggy carbonate reservoirs to lay a geological foundation for the reservoir prediction.In view of the characteristics of the Ordovician reservoirs,the fine imaging technology(cored with pre-stack time migration and object fine processing)of fractured-vuggy carbonate reservoir is developed.Through reservoir calibration and forward modeling analysis,a geophysical recognition mode(including logging recognition mode and seismic recognition mode)for carbonate fractured-vuggy reservoir is established and it provides evidences for reservoir recognition and prediction.To effectively predict the carbonate zones with highly developed fractures and vugs,technologies,such as amplitude variation,coherent cube analysis,and wave impedance and inversion,are also adopted.

Key words: well-developed zone of vugs, geophysical recognition mode, heterogeneity, reservoir prediction, fractured-vuggy carbonate reservoir, Ordovician, Tahe oilfield