Design and Analysis of Multi-well Interference Tests

Conventional interference tests conducted in geothermal reservoirs are used to assess bulk transmissivities and storativities as well as the productivity and size of a geothermal reservoir. Hydrological heterogeneities such as no-flow and pressure support boundaries can also be identified using such tests. In a typical interference test a pressure disturbance is created in one well and the pressure response is measured in one or more wells. Analysis of such tests is straightforward if only one well is active. In this paper presence of more than one active well in interference tests is discussed. Design and analysis of an interference test where more than one well is active is presented using data obtained from a geothermal reservoir located in West Anatolia, Turkey. The analysis was conducted by including the effects of other flowing wells using superposition in time and space. It has been observed that careful interpretation is required to obtain correct reservoir properties from interference tests. It has been also observed that numerical test analysis is not superior to analytical analysis due to additional data requirement.