METHOD TO DETECT LOW SALINITY INJECTION WATER ENCROACHMENT INTO OIL FORMATIONS

摘要

The method comprises the steps of : introducing acid into the hydrocarbon-producing wellbore at a pressure substantially lower than that pressure required to fracture the formation, obtaining primary logging of the formation utilizing neutron logging equipment to establish a baseline reading after the introduction of the acid prior to injection of water; injecting water into the formation through an injector well after establishing the baseline reading; obtaining secondary logging of the formation utilizing neutron logging equipment after the injection of water to establish a post-flood reading, identifying of differential between the post-flood reading and the baseline reading such that the differential is operable to identify low salinity water encroachment. Embodiment particularly directed to horizontal wellbores are also disclosed.