Ten Years of Reservoir Monitoring with Chemical Inflow Tracers - What Have We Learnt and Applied Over the Past Decade?

Abstract

The initial development of inflow tracers was initially designed to provide qualitative information about identifying the location of water breakthrough in production wells. The proof of concept and application for water detection, initiated the development of oil tracers for oil inflow monitoring. Different approaches to install them permanently within a completion component were used, to provide risk free, reliable production monitoring without the need for intervention. Installing unique chemical tracers that are embedded in polymer materials in sand screens or pup joints, along select locations in the lower completion was to correlate where the oil and water is flowing along the production interval and how much. Innovation in the chemistry and materials designed to release to a target fluid (oil or water), enabled non electric wireless monitoring capabilities for many years of longevity in harsh well conditions, such as high temperature and highly acidic stimulation fluids. The evolution of inflow tracer signal interpretation, qualitative and quantitative interpretation workflows using models have also provided valuable insight to inflow characterisation. The latter can provide zonal rate information like wireline conveyed production logging tools, by inducing transients through shut in's or rate changes to create tracer signals that are transported by flow to surface and captured in sample bottles for laboratory analysis. A model based approach to match the measured signals with proprietary models through history matching workflow has also been developed. There are hundreds of well installations utilising inflow tracing monitoring technology today, where the majority have been in open hole completions in both sandstone and naturally fractured carbonate reservoirs on land, offshore environments in both platform and deep water sub-sea environments producing through long tie backs to FPSO's. The monitoring sensors are adaptable to most completion types in conventional and unconventional reservoirs. In most cases, inflow tracers can monitor clean-up efficiency, any subsequent restart and steady state production. Practical case studies will discuss the development of robust and reliable inflow tracer and technology and how operators have applied it over the past decade in a chronological order.

Evaluation of the Release Mechanism of Sustained-Release Tracers and its Application in Horizontal Well Inflow Profile Monitoring

“…The chemical tracer is an efficient monitoring technology with many useful applications in the oil and gas industry, including evaluation of the remaining oil saturation, waterflood optimization, and improving reservoir characterization, fluid pathways, and connectivity between wells. − With the development of chemical tracer technology, it is more and more widely used in a single-well test. Some scientists presented the application, implementation, and analysis of tracer flow back into unconventional reservoirs to determine the individual stage flow patterns and a qualitative correlation between the tracer flow back profiles and the complexity of the fracture networks. − In recent years, a new type of a downhole sustained-release tracer used for production monitoring is developed and applied in the horizontal wells . The working principle of sustained-release tracers includes embedding a unique chemical tracer in a porous polymer matrix that can be released after contacting with sensitive fluid.…”

“…17−20 In recent years, a new type of a downhole sustained-release tracer used for production monitoring is developed and applied in the horizontal wells. 21 The working principle of sustained-release tracers includes embedding a unique chemical tracer in a porous polymer matrix that can be released after contacting with sensitive fluid. The sustained-release tracers are placed in selected locations along the well to provide a permanent monitoring system, supplying information about 22 (1) the production zones, (2) the relative contribution of each zone, (3) the changes in the relative contribution of each zone over time, (4) the position of water breakthrough, and (5) the performance evaluation of the completion technology.…”