Abstract
Unconventional wells often show linear flow. Rate Transient Analysis (RTA) so far has only concentrated on the primary (early-time) linear flow. However, real production data has often shown more than one transient flow regimes. There are only few studies that focus on analyzing the flow regimes following the primary linear flow. It is not clear how to deal with the transition period as well as the compound (late-time) linear flow. When does the transition start? How long does the transition last? Does compound linear flow always exist? What are the diagnostic values of analyzing the period of transition to compound linear flow? This work answers these questions.
We developed a dimensionless typecurve for a single multi-fractured horizontal well (large inter-well spacing). We investigated the end of the primary linear flow, the duration of the transition and the start of the compound linear flow, for different fracture spacing to fracture half-length ratios. We investigated the effect of skin and superposition time functions. In the end, we proposed a workflow to analyze the production data from multiple-fractured horizontal wells by using the newly developed typecurve, and we presented a field example to show the application of the proposed methodology.
