1.1. PLANNING AN INTERWELL TRACER TEST

1.1.1. Wells to trace

The purpose of interwell tests and the kind of technical information that can be derived from them are described above both for oil fields and geothermal fields.

For both reservoir types the interwell tracer tests give quantitative information on the fluid dynamics in a reservoir. Dynamic information from a reservoir may, in addition, be obtained by three other methods: (i) logging of production rates (profiles) of reservoir fluids, (ii) pressure testing and (iii) time- lapse seismic examinations (4-D seismic). However, these methods and tracer testing are complementary and cannot directly replace one another.

Selection of wells to trace must be based on the best available information on the reservoir and the additional knowledge needed in order to optimize reservoir performance. The technical personnel with the most intimate knowledge of the reservoir lithology, stratigraphy and structure are the reservoir engineers together with reservoir geologists. Therefore, an optimum selection of wells should be performed in teamwork with these specialists and the tracer specialist.