Drilling The Longest Reentry Well in Khafji Joint Operations with Smart Fit for Basin Drilling Services

Abstract

Abstract To boost the target production and to achieve the Kingdom of Saudi Arabia and the State of Kuwait visions, Khafji Joint Operations (KJO) started evaluating new projects to boost their daily production in 2020. KJO decided to drill an exploratory reentry well to confirm the existence of oil beyond the known area in one of its carbonate formations. This objective required drilling the longest reach reentry well in the field. The well challenges were to sidetrack from a vertical existing well with high-collision risk and passing through shaly formations associated with wellbore stresses and instability. Also, other difficulties were drilling across zones with high risks of lost circulation and geological uncertainty. To effectively ensure reducing the drilling cost and flawless operations, an integrated solution from different domains including drilling, geomechanics, petrophysics, mud logging, well placement and drilling fluids were included in the project. Drilling challenges have been reviewed from offset wells and previous drilling performance was analyzed to deliver a comprehensive well risk assessment. The risk assessment dictated different measures to be taken in the planning phase. First, a geomechanics study was used to optimize the trajectory design and define trajectory limits for each formation. Second, engineering analysis included a finite-element drilling dynamics study to evaluate combining the rotary steerable system (RSS) bottomhole assembly (BHA) with logging while drilling (LWD) to predict the dynamics and dogleg capability. Third, recommended drilling practices and roadmap were provided with contingency plans for anticipated risks. Finally, different drilling, formation evaluation, and geosteering services were included in the well design requirements to provide challenging well profile, real-time data assurance and decision making on reservoir fluid characterization, reservoir description, and detailed fracture characterization, which will be critical for proper well placement and delivering well objectives. The well was successfully drilled, meeting the required objectives and delivered the longest reentry lateral in Khafji offshore using the latest generation of RSS and full geosteering and petrophysical technologies which enabled a cost-effective well placement solution in a complex geological environment with high uncertainty. The well delivered the required reservoir evaluation objectives, which opens additional future opportunities with similar application in Khafji field.