This paper presents the integration of two surveillance technologies, inflow & inter-well tracers in an Abu Dhabi Offshore field, for the first time to monitor a complex multi-layered reservoir with early stage water injection. Inflow tracers are chemicals with unique identities, installed into the lower completions that penetrate different layers in the reservoir. Inter-well tracers are also unique chemicals injected into injection wells. Tracer technologies allow non-electric wireless monitoring of the reservoir for many years while reducing cost and operational efficiency. In both technologies, data capture requires to fluid samples to be collected and analysed to detect the unique tracers in the production wells. Inflow tracers provides both qualitative and quantitative estimates of zonal flow as well identifying the source of water breakthrough. Inter-well tracers introduced in the injection wells can identify the primary flow paths and rate of movement of injected fluid in the reservoir. This information can be used to evaluate water channelling and improve water flood conformance plans to maximize sweep efficiency.
The planning and design stage included a selection of pumpable inter-well tracers, volume calculation and breakthrough time simulations to determine the tracer mass required to meet the monitoring objectives. On the other hand, inflow tracers were designed to account for high temperature and highly acidic stimulation fluids and placed along the producing intervals in the lower completion. Quantification models will be utilized to quantify the zonal influx while accounting for expected cross flow. The execution plan is defined by the optimum production and injection rates, equipment and lab test requirements, and optimized field sampling schedule for transient and steady state flow campaigns.
The co-implementation of both tracer technologies in the early stage of waterflood development offers unique ability to monitor the reservoir, eliminating the need for expensive, complicated offshore logistical arrangements for time-consuming wireline interventions to manage the reservoir more efficiently and maximize recovery.