Atwood Oceanics Inc. operates as an offshore drilling contractor focused on the drilling and completion of exploratory and developmental oil and gas wells for the global oil and gas industry; its fleet previously comprised ultra-deepwater drillships including the Atwood Admiral and Atwood Archer, semisubmersibles such as the Atwood Eagle, jack-up rigs, and managed platform drilling units; services encompass contract drilling, management, and consulting across diverse water depths from shallow to ultra-deepwater. The company targets major oil and gas operators like Noble Energy, Royal Dutch Shell, Woodside Petroleum, Chevron Corporation, and Kosmos Energy, deriving significant revenues from deepwater semisubmersibles and drillships which accounted for 76% of fiscal 2015 totals, with 71% of revenues generated outside the United States particularly in Australia, the Gulf of Mexico, Mediterranean Sea, West Africa, Southeast Asia, and offshore Australia. Founded in 1968 and headquartered in Houston, Texas, Atwood Oceanics traded on the NYSE under ticker ATW until its delisting following acquisition. In 2017, Ensco plc completed its all-stock acquisition of Atwood Oceanics, with Atwood shareholders receiving 1.60 Ensco Class A ordinary shares per Atwood share, integrating Atwood's assets into Ensco's fleet of 63 rigs including 26 deepwater floaters and 37 jack-ups for enhanced scale and $65 million in anticipated annual expense synergies; Ensco later merged with Rowan Companies in 2019 to form EnscoRowan plc, which rebranded to Valaris plc effective July 31, 2019, under ticker VAL, operating as the combined entity's offshore drilling platform with Atwood's legacy assets contributing to its high-specification floater and jackup capabilities amid industry consolidation and restructuring including a 2020 Chapter 11 bankruptcy filing.