Intelligent Inflow Tracers Obtain Information With Less Risk, Cost

Abstract

Young Technology Showcase Today’s field developments are increasingly characterized by complex wells in demanding and costly operating environments. Not only are individual wells challenging, but most are part of a complex reservoir network that must be managed over an extended period. The high cost and risk of acquiring reservoir surveillance information using conventional technology, such as production logging tools, is forcing operators to manage these fields without knowledge of the inflow distribution across the reservoir interval. In addition, permanent reservoir surveillance solutions based on optical or electronic sensors require major modifications of the completion design and installation procedure. Consequently, a significant amount of complexity and risk are added to the project, making the use of such technologies prohibitive. Intelligent chemically based inflow tracer systems are an emerging technology that consist of engineered polymers and chemical compounds combined into a product that resembles strips of plastic. The tracer system is designed to react to either oil or water. For example, when a water-sensitive tracer system is contacted by water, the tracer system releases its unique chemical identification (inflow tracer) at a prescribed release rate, irrespective of the flowing conditions. The water-sensitive tracer system is dormant when contacted by oil, gas, or air. The oil-sensitive tracer system behaves similarly as the tracer is released only when it comes in contact with oil. Strips of the tracer system are readily integrated into almost any completion configuration including conventional sand screens, inflow control device (ICD) sand screens, multistage fracturing systems, pup joints, and intelligent completions. Additionally, the tracer system can be cemented behind casing and perforated through, providing contact between reservoir fluids and the intelligent tracer strips. In summary, the intelligent tracer strips can be deployed in almost any well type without affecting the installation process. Samples of produced fluid are analyzed for the concentration of each intelligent tracer. Tracer concentration data, combined with model-based interpretation techniques, enables the operator to understand where oil is entering the well, where water influx is occurring, and relative oil contributions of monitored zones.