Abstract: Lower W uerhe reservoir of Upper Permian in District No.8 of Karamay oilfield is a massive fractured conglomerate reservoir with edge-bottom water and extra-low permeability. This paper presents the numerical simulation studies of the complex fractured reservoir. In view of its characteristics of non-pay zone yielding, injected water leakage, watered-out and water breakthrough well, formation water inflow and different waterflooding models, several approaches for detailed history matching are adopted to over 400 wells for 23-year production, and single well pressure and water cut simulation reach the coincidence rate of 85%. These simulated results could be as a guide for numerical simulation of another similar reservoirs, and these special approaches could be applicable in other fractured low permeability reservoirs.

Key words: Karamay oilfield, low permeability reservoir, fracture, numerical simulation, history match