An Innovative Wellbore Cleanup Solution for Non-Cemented Lower Completions Saves 27 Million$ in ADNOC Onshore

Abstract

The long-term development of any mature field requires a fresh perspective of long MRC (Maximum reservoir contact) wells and increased well accessibility. To improve well accessibility the deployment of lower completion has been a mandate. Onshore UAE Field demands drilling Slim hole (6″ /6-1/8″ ) laterals and Slim Hole ERD (Extended reach drilling) wells with 4.5″ Uncemented Lower Completion. This paper highlights the innovative wellbore cleanout procedure prior installation of Lower Completions. Conventionally, using Water Based Mud (WBM) with high friction factors in 6″ Horizontal Hole (HH), two trips were required to reduce the friction factor prior running the Lower Completion. The optimized solution allowed wellbore clean-up and displacement of brine in one trip with drilling assembly (BHA). This innovative technique eliminated one dedicated trip for wellbore cleanout and thus saved millions in CAPEX and Business Plan days. The T&D data for 5 wells with dedicated cleanout trip were compared to clean-out with 6″ drilling BHA with viscous-lubricated brine. The 6″ BHA was optimized to fit with innovative dormant drilling scrapper and lubricated viscous brine was displaced in the Open Hole. A thorough hole cleaning procedure was formulated and was applied to all the wells. After analyzing over 5 wells, it was observed that in both runs, the one with 6″ BHA compared to dedicated cleanout-trip, the torque and drag values were similar and the effective reduction in friction factor was similar. This supported the elimination of planned dedicated cleanout trip and saved average 2 days/well and 27MM$ for year 2022. This optimized BHA design with enhanced hole cleaning procedure was a keystone in deploying slim 4-1/2″ lower completion in WBM system. This practice led to successful deployment of First Slim Hole ERD in UAE with 15000ft of 4-1/2″ lower completion with WBM system. This was a one-of-a-kind achievement in UAE.

Aqueous drilling fluids systems incorporated with green nanoparticles and industrial spent caustic: Optimum rheology and filtration loss properties

“…PV = reading at 600 rpm -reading at 300 rpm (1) YP= reading at 300 rpm -PV (2) AP = reading at 600 rpm / 2…”

“…The effect of proper selection of drilling fluid on drilling operations has always been a very significant topic to discuss, also, drilling fluids cost has always been a very vital factor that has greatly affected the process of selecting the proper required fluid. Water-based mud types are generally costeffective, and this makes them become workable in various situations [1], while, oil-based fluids have always been characterized to be expensive and costly [2], which generally makes them unfeasible in some cases. It is worth well recognizing that cost, technical performance, and environmental impact are the three main basic and effective reasons to guide the correct and proper selection of the drilling fluids [3].…”