Reservoir Features and Exploitation Strategy in Pingqiao Hard-to-Recover Area of Ansai Oil Field

Undeveloped oil-bearing reservoirs are often located in edging areas of reservoirs,with unfavorable physical properties and low abundance.Compared with developed areas,Pingqiao hard-to-recover area is characterized by fine detrital particles,high in terstitial matter content,unfavo rable physical property,big displacement pressure and median pressure,little areal porosity (particularly very little residual intergranular pore).It is a typical extra-low permeability reservoir,which has characteristics of obvious non-Darcy percolation,high kick-off pressure gradient,water-sensitive and flow-sensitive damage caused by particle migration when clay mineral disperse in water.In order to reduce reservoir damage,to increase the ability of reservoir infiltration and to build effective pressure displacement system,the following techniques were used in Pingqiao hard-to-recover area: detailed reservoir description,well pattern optimization,advancing waterflooding,fracture reconstruction programme optimization and clay stabilizing technique.These techniquesmet their goals notably and effectively.