Improved Understanding of Reservoir Fluid Dynamics in the North Sea Snorre Field by Combining Tracers, 4D Seismic, and Production Data

摘要

To obtain improved oil recovery (IOR) it is crucial to have a best possible description of the reservoir and the reservoir dynamics. In addition to production data, information can be obtained from 4D seismic as well as tracer monitoring. Interwell tracer testing (IWTT) has been established as a proven and efficient technology to obtain information on well-to-well communication, heterogeneities and fluid dynamics. During such tests, chemical or radioactive tracers are used to label water or gas from specific wells. The tracers are then subsequently used to trace the fluids as they move through the reservoir together with the injection phase. One of the appealing features of IWTT is that at first tracer breakthrough in a producer, immediate and unambiguous information on injector - producer communication is given. However, gas and water re-injection might complicate this simple evaluation, and later in the production history, this effect should be evaluated. Despite the appealing features of IWTT, they are still underutilised in the petroleum industry, and few of the tracer studies that are actually performed utilise the data to their full capacity - most tracer data are used in a qualitative manner [1]. To improve this situation, we combine tracer data evaluation, 4D seismic and available production data in an integrated process. The integration is demonstrated using data from the Snorre field in the North Sea. In addition to production data, extensive tracer data back to 1993 and results from three seismic surveys acquired in 1983, 1997 and 2001 were considered.