Method for enhanced oil recovery by geopressured waterflood

摘要

The recovery of petroleum produced from an oil reservoir is enhanced by injecting water such as from a geopressured aquifer having a natural gas content at or near saturation at a temperature above 300 DEG F. into the oil reservoir at a flow rate sufficient to develop a back-pressure in the oil reservoir equal to between about 80% of its fracture pressure and a pressure below its fracture pressure and producing oil from the oil reservoir when the injection of water necessary to maintain the back-pressure below the oil reservoir fracture pressure drops below a predetermined level. The recovery of petroleum also is enhanced by using sand screening means to complete a portion of the well bore penetrating into the oil reservoir and a straddle packer assembly means which can be raised and lowered relative to the screening means.