This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper OTC 25437, ’Mars-B Development: Well Challenges and Solutions - An Evolution of Traditional Well, Rig, and Facility Design,’ by Arno L.M. van den Haak, Wylie J. Cameron, Lisa S. Grant, Nor Janiah H. Japar, and Deandre R. Reagins, Shell, prepared for the 2014 Offshore Technology Conference, Houston, 5-8 May. The paper has not been peer reviewed. The Mars-B project is the operator’s sixth Gulf of Mexico (GOM) tension-leg- platform (TLP) development. The Mars-B project is aiming to unlock resources over the next 50 years through the deployment of a new 24-slot TLP structure [the Olympus direct-vertical-access (DVA) TLP] and additional subsea infrastructure for the west Boreas and south Deimos fields. The Olympus rig is a novel platform drilling rig designed specifically to meet the execution requirements of complex well designs. A high-level overview of the design challenges and the resulting surface-equipment requirements of this project is discussed in this paper. Introduction The operator discovered the Mars field in the Mississippi Canyon Area Block 763 in 1989, located 130 miles southeast of New Orleans in approximately 3,000 ft of water. The Mars-B project made its final investment decision in September 2010 to expand the existing Mars operation with a new 24-slot TLP structure and additional subsea infrastructure for the west Boreas and south Deimos fields. The Olympus TLP is located approximately 1 mile southwest of the existing Mars TLP and represents the first brownfield development of a deepwater field in the GOM. It will enable production of an additional 1.1 billion BOE over the approximately 700 million BOE that has been produced today with the Mars TLP.