A Seamless Execution of Managed Pressure Drilling Controlling Drilling Hazards and Pore Pressure Uncertainty Related High-Pressure High-Temperature in Horizontal North Kuwait Jurassic Deep Wells

Abstract The objective of the project is to drill a horizontal 6 in hole section through Najmah Formation in North Kuwait by utilizing Managed Pressure Drilling to define Pore Pressure uncertainty, reduce extra overbalance to mitigate hazards of losses, maintaining pipe rotation during well control events and differential stuck and utilizing Early kick/loss detection system. The well is located in a naturally fractured zone. Overall, Najmah's stratigraphy is divided into four lithological units, two of which are clean carbonate-platform limestones, and the other two are organic-rich. Its reservoir properties are dominated by fractured porosity and extremely low classified as a tight reservoir in terms of permeability In collaboration with Kuwait Oil Company (KOC) and Weatherford, a high-level strategy was developed by following the recommendations shared in a Pre-section Geomechanics Data Package (PSGDP). The package included estimated pore pressure values, based on a 5-point system analyzed by a precise study of the drilling hazards from offset wells highlighting the risks associated with and lessons learnt. Majority of the offset wells drilled were complex sections encountering challenging drilling hazards, specifically severe losses from the start up of the section to the target depth leading to None-Productive Time in the conventional approach to resolve the encountered issues, cement plugs, bull-heading in case of well flowing. With the given data the MPD drilling program planned an Equivalent Circulating Density of not higher than 12.4 ppg as target while utilizing MPD-CBHP Application to manage the bottom hole pressure in case encountering the high pressure of 13.99 ppg and to avoid bull heading by precise monitoring and quick response of adjusting ECD in case of experiencing gain and manage to circulate out the influx within MPD's given capabilities. The application of MPD technique allowed efficient and safe drilling through a highly uncertain pressure window by performing a number of MPD-Dynamic Pore Pressure Tests providing real-time pressure assessments. MPD techniques in the section included staged mud weight reductions from 14.5 to 11.2 ppg, tandem pill applications, backpressure management during connections, and continuous monitoring of background gas and flow stability. The final section was drilled with BHECD ranging from 12.36 to 12.18 ppg, with no total loss events compared to offsets, controllable returns losses (≤15 BPH). The section also encountered high gas and well-flowing and was safely circulated the gas to the flaring line, highlighting the efficient use of MPD for effective well control and kick-loss situation management The liner was successfully run and set at 18,860 ft MD with static conditions and efficient hole cleaning, reinforcing the value of MPD not only in drilling but also in casing and completion operations. The flawless execution showcases the value of collaboration in the latest geomechanics workflow, supporting KOC's journey by optimum mud weights to overcome challenges to use the proper completions in similar wells.