A vertical or horizontal well producing from multiple fractures exhibits a characteristic response during production or pressure transient testing that can be used to identify the geometry of the fracture system. Both well test analysis and production data analysis methods are available, or being developed, that focus on indentifying the productive fractures using intrawell fracture interference observed in either transient or production data. For example, in a multi-fractured horizontal well, analysis of the early-time production data can be used to approximate the number of producing fractures and the fracture geometry along the lateral.

 The new interpretation methods require observing interference between fractures along a single wellbore, that is, intrawell interference, which must be differentiated from the more commonly observed interwell interference. Since interference between fractures occurs relatively quickly, the analysis methods focus on matching early-time transient or production data to type curves.

 A key to interpreting the early-time production data is a prefrac measurement of permeability-thickness, kh, and often a DFIT or fracture-injection/falloff test is the preferred well test prior to hydraulic fracturing. This presentation also demonstrates the latest interpretation methodologies of DFIT data, and shows how DFIT data is used with production data to infer the number of fractures producing in a multifractured horizontal well. Field examples are included to demonstrate the methodology for both DFIT analysis and interpreting intrawell interference.