The North Buck Draw Unit (NBDU) produces volatile oil from the Dakota sandstone in the Powder River basin. This high-pressure miscible-gas-injection project with 16 producers and 8 injectors has been in operation for 11 years. The unit area covers 8,800 acres. Ultimate oil recovery will exceed 23 million bbl, 65% original oil in place (OOIP). incremental recovery is approximately 15 million bbl more than primary estimates.