_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 204550, “Breaking ERD Records With Optimized Engineering and Practices: Making the Impossible Possible,” by Hussien Alzaki, SPE, Saudi Aramco; Nadhir Rahmani, Schlumberger; and Matthew Carr, K&M Technology Group. The paper has not been peer reviewed. _ The complete paper describes preplanning, execution, and results of extended-reach drilling (ERD) with a large-bore design of 12¼ in. as the main stepout section and deploying 9⅝-in. casing on a shallow true vertical depth (TVD) of 4,200 ft. Progressive increase of ERD ratio and complexity from one well to the next was planned and executed until a record-breaking well had been achieved, deploying 8 km of 9⅝-in. casing with a 5.4 ERD ratio at 26,179 ft total depth (TD) horizontally all the way. Planning Consideration and Risk Assessment The presented ERD campaign was unusual because of its combined ERD ratio and very shallow TVD for the long horizontal sections. In addition to the obligation to reach the targeted formation in a 12¼-in. hole, complex challenges were addressed, such as the obligation to kick off and drill large holes (12¼-in. horizontal hole section and 9⅝-in. casing) up to a 5.4:1 ERD ratio at 4,200 ft (approximately 1,300 m) TVD. The solution involved implementation of technically modeled engineered solutions that were verified during execution. Operational procedures included the following: - Proper planning and execution of well profiles to ensure optimal placement in a specific formation and minimum side force - Drilling and tripping procedures to ensure the lowest friction factor (FF) and allow drilling to TD with a limited rig capability - Engineered solutions for casing-running technologies, which involved rotation and conventional running and flotation Following risk assessment and the multiple peer reviews made for the subject well, a drilling plan was established that addressed the anticipated main limitations, which included the following: - Bottomhole assembly (BHA) and drillstring design to allow reaching TD within optimal rig capacities - Bit selection to reduce the number of - runs needed to two (three maximum if a contingency were to be considered) - Total dissolved solids (TDS) torque-limit management (30,000 lbf-ft at 180 rev/min) - A rig-pumping pressure limit of 4,600 psi - Hole-cleaning and FF management to prepare for deployment of 9⅝-in. casing