Transient, sandface temperature solutions for horizontal wells producing dry gas

Multiple recent studies have shown that the bottom-hole, transient temperature can be used to estimate formation properties including permeability-thickness and depth of damage, to identify produced phases, as well as to allocate zonal flow rates. The appropriate methods for temperature interpretation are being developed worldwide as part of the Temperature Transient Analysis (TTA) methodology. To-date, most of the TTA solutions have been developed for vertical wells. The TTA for horizontal well is more complex with only few solutions available so far, despite the high demand since the high-precision, downhole temperature sensors are widely installed in horizontal, intelligent wells. Moreover, to our knowledge no TTA solutions are yet available for gas producing horizontal wells. This work fills this gap by presenting analytical and semi-analytical solutions for transient sandface temperature in gas producing horizontal wells. We first present novel, TTA solutions developed for linear flow around a horizontal well with semi-infinite, constant pressure lateral boundaries. Further, the semi-analytical transient sandface temperature solution is also presented. Finally, the effects of heat transfer between the reservoir and the surrounding formation and the effects of flow convergence are considered. These results are an important step in the TTA development and effective use in modern wells.