“…Well logs are useful not only to identify bedding planes, fractures, reservoirs, and fault zones, but also to infer information, such as the physical properties of rocks, lithology characterization, and stress fields. Well logs are of great value to carbon capture and storage (Förster et al, 2010; Tsuji et al, 2014), geothermal energy utilization (Vallier et al, 2019; Vik et al, 2018), earthquake study (Kim et al, 2018; H. Li et al, 2013), groundwater science and engineering, and the exploitation of subsurface resources, such as oil, gas, and minerals (Alexeyev et al, 2017; Wendt et al, 1986). However, obtaining well logs is usually expensive and time consuming, which leads to two challenges: (1) The full set of logs is not always available in practice; and (2) even when the logs are measured, the number of logs is often small, resulting in a small‐data problem (few‐shot learning).…”