Retrieving up to 50 1.5-in.-outside-diameter by 2.5-in.-long sidewall-core samples from a single descent into a well, the Schlumberger XL-Rock large-volume rotary sidewall-coring service closes the gap between core plugs from continuous conventional core and wireline-conveyed rotary sidewall cores. This coring service enables collecting sidewall-core samples equivalent to standard laboratory core plugs. The coring tool is run in combination with a gamma ray tool to correlate with openhole logs for accurate, real-time depth control of the coring points. With the new coring capability, operators can characterize an extended reservoir interval in a single sidewall-coring descent instead of multiple sidewall-coring descents or multiple strands of whole-core retrieval.