注海水油藏强水淹层开发潜力再认识OA

Constrained by the development conditions and economic viability of offshore oilfields,seawater injection is widely adopted in some offshore oilfields.To solve the problem of inaccurate potential evaluation for strongly water-flooded layers in such reservoirs,this paper takes advantage of the characteristic that the resistivity of reservoirs flooded by high-salinity seawater is lower than that of layers flooded by freshwater.Based on the mixed-fluid salinity formula and the Simandoux equation,the resistivity of the mixed fluid under high-salinity water injection is calculated.In the absence of neutron-density logging data,the remarkable variation in reservoir resistivity after high-salinity water flooding is further utilized.Combined with the relationship between the resistivity of water-flooded layers in adjustment wells and the actual water cut after production in the PX Oilfield of Bohai Bay over the years,a correlation chart between reservoir flooding degree and water cut is established.This research renews the understanding of the potential value of strongly water-flooded layers in seawater-flooded reservoirs and provides important technical support for tapping remaining oil potential in offshore oilfields at the high water-cut stage.