The oilfield-development plan (ODP) for a shale gas field at the southern edge of the Sichuan Basin in China started in early 2014. The first wells drilled in the field and its adjacent blocks experienced significant challenges, such as severe mud losses, stuck tools, losses in the hole, high treating pressure, and unexpected screenout. Because an accurate understanding of geomechanics and its roles at various scales is vital, 3D full-field and pad geomechanics models were developed for achieving efficiency and effectiveness in implementing the ODP.
Introduction
The Ordovician-Silurian Wufeng-Longmaxi hot shale is an emerging shale gas play in China.
Currently, the major exploration and development activities of the play are in the Sichuan Basin and its adjacent areas. For shale gas development in the Sichuan Basin and its adjacent areas, using the megascale, high-density, and continuous and regular pad drilling as is used in North America is difficult because surface and subsurface conditions are significantly different from those of the well-known North American shale plays.
The strong environmental and social constraints that typify the Sichuan Basin and surrounding area are shown in Fig. 1 above. Drilling pads for shale gas developments are commonly located in narrow valleys that are often home to farmland and residential villages with dense populations.
