Technology Update: Custom Biological Produced Water Treatment Yields Fast Oil Recovery Boost in Waterflood

Abstract

Technology Update Improving oil production from mature fields is a significant challenge because of rising recovery costs and fluctuating crude oil prices. Although large investments are made in finding new reserves, typically more than 60% of discovered oil is left behind. Thus, the use of enhanced oil recovery (EOR) technologies is necessary to bring more of this oil into production. This article describes how the use of a biological EOR technique that applied produced water for reservoir flooding in a mature field led to rapid and substantial increases in oil production. Glori Energy’s Activated Environment for Recovery of Oil (AERO) technology is a biological EOR method in which customized nutrients are injected into the reservoir to activate native microbes. The ensuing microbial activity improves oil mobility and leads to increased production in waterflooded sandstone reservoirs. Use of the technology involves minimal capital spending and low operating costs, and applications can use existing field infrastructure. Reservoirs respond quickly to the use of the method, showing higher oil rates and increased oil cuts. Recovery is increased, and the economic life of the field is extended. Oil fields are screened in a two-step process that includes reservoir analysis and treatment design. Reservoir analysis involves geological assessment to determine key characteristics such as porosity, permeability, structural alignment, net pay, oil gravity, injector/producer continuity, and historical production response. The analysis allows for a quick review of multiple fields to select the one predicted to benefit most from biological EOR. Treatment design comprises biochemical testing and nutrient formulation. The process starts with the sampling of reservoir fluids under controlled conditions, using specialized equipment from pertinent locations such as injection, production, and source-water wells. Chemical analysis is begun immediately upon the sample’s arrival to determine the physicochemical characteristics of oil and water. Biological testing comprises assessing the viability of native microbial populations, developing a customized nutrient blend tailored to the field, and confirming the suitability of injection water for supporting microbial activity.