Planning and Execution of MRC / ERD Well with Slim Lower Completion PPL in Al Nouf Field, Abu Dhabi, UAE

Abstract

Well was drilled in Al Nouf field with the objective to support the pressure sustainability of multiple producer wells across Shuaiba-1 formation based on MRC / ERD approach. This paper presents the challenges faced in planning and drilling of subject well and successfully running of slim lower completion to total measured depth of 21,000ft (6.4 km) with having horizontal section of 10,450ft (3.18 km) with directional difficulty index (DDI) of 6.520 using slim casing design. Planning of this well commenced by meetings and collaboration with subsurface operation and reservoir team with the common objective of drilling a well of over 11,000ft horizontal extent and having a capability of running 4 ½" pre-perforated liner with multiple swell packers as lower completion to well TD of (21,000ft) across Shauiba - 1 reservoir. Purpose of lower completion are to properly control the well injectivity regime and support multiple producers across SH-1. All the associated risks were highlighted and mitigated by proper planning and engineering analysis such as trajectory, collision risks, BHA, hydraulics and casing design. This MRC injector well of 21,000ft MD / 8953 ft TVD (2.34 ERD H:V ratio) is the first well in the region to have 11,000ft of geo-steered 6" horizontal section with slim lower completion installed till TD of well. This paper will explain the innovative approach of mitigating the challenges faced while drilling a complex well of 3500ft departure and have a horizontal section of over 11,000ft with 6" drainage. A few challenges like collision risk at surface & horizontal section with total losses across aquifer were major disquiet but successfully catered. Second major challenge was to run 4 ½" pre-perforated liner of 11,000ft with multiple swell packers (each 1000ft) to TD of well were immaculately mitigated with advanced engineering analysis and innovative technologies like swivel master etc. Results from this well have proven that having lower completion in MRC / ERD wells have significantly improved the well accessibility and well performance and enhanced the reservoir management and significantly reduced the field development cost. This paper summarizes the practice and technology used to drill successfully the MRC / ERD well in artificial island and running of slim lower completion across horizontal section till TD of well. The challenges and its mitigation explained in this paper will support the idea of having lower completion in MRC/ERD wells which helps to stretch the reservoir boundaries and have more control on injectivity / productivity of reservoir because of proper isolation by swell packers and have maximum well accessibility across ERD horizontal section.