Pushing the Technical Limits in an 8½-in. Section of Manifa ERD Wells Through a Redesigned PDC Bit and Reengineered Drilling Practices

Abstract

Abstract Over the field development life of the Manifa extended-reach-drilling (ERD) project, extensive drilling tools and practices were introduced to continuously improve drilling performance and well delivery times. One of the main challenges encountered in Manifa ERD wells lies in landing the 8½-in. section into hard carbonate rocks. Historically, a motorized rotary steerable system (RSS) was used to manage the downhole stick/slip and vibrations experienced by the bottomhole assembly (BHA) while crossing the interbedded hard layers in the 8½-in. section. Engineering efforts were implemented to determine an alternate drilling strategy for the 8½-in. section to overcome such drilling challenges—at lower cost and with a higher performance impact. Using 4D simulation software, the drill bit was completed remodeled so it could be used on an RSS BHA and still minimize the vibration on drilling tools. This involved revising the cutter count, cutter placement, angle of attack, hydraulics, and gauge configuration. In addition, a thorough drilling parameters road map was modeled to help mitigate downhole vibration. The objective was to constantly remain within the RSS and measurement/logging-while-drilling (MLWD) tool shock limitation to increase their life and ensure reaching the target entry in a single run. Drilling practices were optimized by focusing on improving connections and reaming times without compromising hole cleaning. This performance initiative was implemented in the field in three steps and resulted in unprecedented drilling performance, achieving a record in drilling this long directional 8½-in. section. As a first step, the redesigned drill bit was introduced in the field to verify the design output in the field and gather the drilling parameters and shock and vibration data with this new design. The design delivered as expected and increased rate of penetration (ROP) by 67% compared with previous records with no shock and vibration recorded on BHA equipment. The second step focused on following the modeled parameters road map from the simulations and improved ROP a further 7%. In the third step of this project, new drilling practices were implemented, which minimized connection and circulation time while maintaining good hole cleaning, tracking of pickup and slackoff weight, and correlating with the torque and drag analysis. The overall drilling performance improved with an increase of 37% in ROP (97.1 ft/hr) over the last record. A total savings of USD 180,000 was achieved on this third attempt, and a new approach to the ERD wells was implemented by the operator's drilling engineering team. This paper will review the progressive design process and will present the detailed results for each run. Insight will be provided on how this process can be applied to increase ROP performance and reduce cost per foot in a variety of drilling applications.