First Successful Run of 17.5 Inch Hybrid Bit in ADNOC Onshore to Drill Deviated Section

Abstract

In the onshore drilling operation the main objective is always finding ways to optimize cost and improve the efficiency of drilling operations. Among the various available option, one possibility was to drill 17.5" deviated section in one run through the interbedded formation, which cause high vibrations and risk of twist-off. This section previously was drilled with minimum 2-3 bit runs for a heavy casing design. This would definitely reduce the well duration and cost. The plan involved to drill 17.5" deviated section using rotary steerable system using hybrid bit technology. Recent advances in drilling bit design has proved to be very effective in drilling surface hole sections but are limited to drill vertical holes and require multiple runs to complete a section. Special design and cutting structure is required when it comes to drill deviated hole. One supplier has combined the traditional design and come up with hybrid bit structure to achieve this goal of drilling surface deviated hole in one run. This special hybrid bit, drilled successfully 17.5" deviated section in one run with enhanced ROP by 40% compared to previous wells. This saved additional trips to change bit and avoided any stuck pipe and twist off. This kind of strategy has helped to maximize average ROP of 64 ft/hr for the entire section. The main element in optimizing the performance of is the systematic approach towards the bit selection, hydraulics and mud parameters. Outcome of this optimization resulted in case history data which shows that this kind of hybrid bit technology can be used to drill deviated wellbore with better penetration rates, lesser washouts and longer on-bottom time. This technical paper describes the results of first well drilled by a service provider using hybrid bit technology with rotary steerable system in one run. This has resulted in increasing the rate of penetration for the 17.5" deviated top hole section. Applying this kind of hybrid bit technology has not only enhanced the ROP but also helped to save rig days and cost.