The objective of this paper is to describe the first application of three unique chemical tracer technologies in the optimization process of a field development in the Black Sea offshore Romania. These technologies helped in the understanding of fluid flow, fracture effectiveness, and completion design. The paper describes the methodology employed and the results obtained from the combined application of water tracers, oil tracers, and gas tracers in one multistage hydraulically fractured well. Additionally, the tracer design, operational logistics, operational lessons learned, results interpretation, and application of the results in order to improve subsequent completions will also be discussed. Clear correlations were seen between the results of all three tracers, which were in turn compared to production and treatment data, further confirming the value of diagnostic technology. The importance of adequate sampling and offshore operational limitations were identified and resolved. Results from a planned, but due to tracer results, not executed water shutoff of high watercut zones are presented. The results were applied to future completion designs and decision-making processes. This case study is an inside look at the first-ever combined application of oil, water, and gas tracers in an offshore hydraulically fractured well development in Europe. It will discuss how the results from using all three chemical tracer technologies, coupled with additional data sets while applying a synergistic interaction between teams, can be highly leveraged to understand current completions designs and optimize future developments.
The applications of tracers can be tied to most disciplines in the oilfield; from drilling to secondary and tertiary recovery. The focus of this paper is in the application of chemical tracers to completion diagnostics and optimization, and in particular, to multistage fracturing operations offshore.
In the multistage fracturing application of tracer technology, there are mainly three sub-categories of chemical tracers: tracers for the gas phase of hydrocarbons, the liquid phases of hydrocarbons, and tracers for the water-based completion fluids. The presented project utilized all three tracer types at the same time.