Successfully Increasing Production of a Mature Offshore Heavy Oil Reservoir by Water Flooding Conformance

Abstract

Q oilfield is a typical fluvial reservoir, which is located in the middle of Bohai Bay. Lower member of Ming (Nm) formation and upper member of Guantao (Ng) formation of Neogene are the main oil-bearing strata, with buried depth -950m ~ -1430m, and developed fluvial sedimentary sandstone reservoir. The lower member of Minghuazhen formation developed meandering river deposit, and sandbody was mainly composed of complex meandering. Guantao formation developed braided river deposit. Each oil group has a good vertical superposition, which shows high porosity and high permeability (average 3000mD), but the oil viscosity of each oil group is quite different (from 22mPa s~260mPa s).