Nabors Industries Ltd. engages in the provision of off shore platform rigs. It also provides performance tools, directional drilling services, tubular running services, and technologies for its own rig fleet and those operated by third parties. It manufactures drilling equipment and drilling rig instrumentation. It operates through the following business segments: U.S. Drilling, Canada Drilling, International Drilling, Drilling Solutions, and Rig Technologies. The U.S. Drilling segment includes land drilling activities in the lower states and Alaska, as well as offshore operations in the Gulf of Mexico. The Canada Drilling segment operates in land-based drilling rigs in Canada. The International Drilling segment focuses on maintaining a footprint in the oil and gas market, most notably in Saudi Arabia, Algeria, Argentina, Colombia, Kazakhstan, and Venezuela. The Drilling Solutions segment offers drilling technologies, such as proprietary drilling-bit steering systems and rig instrumentation software. The Rig Technologies segment refers to the Canrig, which manufactures and sells top drives, catwalks, wrenches, draw works, and drilling related equipment, such as robotic systems and downhole tools. The company was founded by Clair Nabors in 1952 and is headquartered in Hamilton, Bermuda.

Seadrill Ltd. engages in the provision of offshore drilling services. It owns and operates drillships, semi-submersibles and jack-ups. It operates through the following segments: Harsh Environment, Floaters, and Jack-Up Rigs. The Harsh Environment segment operates both semi-submersibles and jack-ups that have a number of design modifications to be able to handle harsh weather conditions. The Floaters segment encompasses its drillships and benign environment semi-submersible rigs. The Jack-Up Rigs segment operates mobile, self-elevating drilling platforms equipped with legs that are lowered to the seabed. The company was founded on May 10, 2005 and is headquartered in Hamilton, Bermuda.

SPDR S&P Oil & Gas Exploration & Production ETF seeks to provide investment results that, before fees and expenses, correspond generally to the total return performance of an index derived from the oil and gas exploration and production segment of a U.S. total market composite index. In seeking to track the performance of the S&P Oil & Gas Exploration & Production Select Industry Index, the fund employs a sampling strategy. It generally invests substantially all, but at least 80%, of its total assets in the securities comprising the index. The index represents the oil and gas exploration and production segment of the S&P Total Market Index ("S&P TMI").