In the deepwater Gulf of Mexico (GOM), an operating company planned to drill and log a challenging wellbore in a mature field within the Upper Tertiary set of target sands. High levels of depletion as well as extremely tight pore pressure margins were anticipated. The operator and the service company's drilling and evaluation (D&E) integrated teams developed a highly collaborative environment from the early planning stage of the project, aligning people and processes and enabling applications. Regional knowledge from an archived geomechanical model was updated during collaborative planning sessions, enabling both parties to have a consistent understanding of the subsurface challenges to correctly drill and log each interval. Potential wellbore instability issues were mitigated using a proactive geomechanics analysis and hydraulics management from an integrated real-time operations center (iROC). Formation compressional slowness from a logging-while-drilling (LWD) sonic system was used, updating the geomechanical model for accurate real-time pore pressure and wellbore stability analysis. Additionally, the sonic system was used for top-of-cement (TOC) evaluation behind the intermediate casing to satisfy the Bureau of Safety and Environmental Enforcement (BSEE) requirements to differentiate fully bonded pipe from free pipe. Geosteering services from real-time log response correlations and at-bit geological predictions were used to correctly geostop for an intermediate casing point before pressure regression. An LWD formation pressure system provided pressure tests over various depth intervals, providing excellent fluid gradient determination for the primary target sand package. An LWD azimuthal density system delivered high-quality borehole images within the 16 ½-in. borehole section, providing dip information for geological correlation to seismic. Further, the azimuthal density image system resolved the interbedded shale/sand sequences, allowing dip analysis for geological model correlation within the reservoir. Challenges for this wellbore included shallow water hazards, wellbore instability, setting intermediate casing above the sand targets, and the depleted reservoir section. The deployment of specific technologies with associated unique applications discussed in detail within this paper led to superior well construction execution under time (8 days) and under budget (USD 4 million).

Operators often use real-time operation centers (RTOC) as a funnel point for data streams transmitted from multiple rigs during the well construction process. A RTOC is typically staffed by subject matter experts (SMEs), with the primary goals of interpreting real-time wellbore conditions and relaying actionable recommendations to help reduce nonproductive time (NPT) and well control incidents. Automation is a strong industry trend. Autonomous systems are being developed to flag potential NPT events before they occur; however, these systems are not yet widely used. In the absence of these systems, workflows among complementary disciplines have been developed to identify potential NPT events in large data streams transmitted to a RTOC. This paper presents example scenarios from deepwater prospects with potential actionable recommendations. Robust data streams transmitted to a RTOC can be received by the overlapping disciplines of hydraulics optimization, drilling optimization, and geomechanics. Staff from each discipline filter through the raw data to capture incoming information relevant to their respective output analysis. A key goal of each discipline is to mitigate the risk of NPT through real-time identification of warning trends observed during deepwater drilling in narrow pressure window situations. The multidisciplinary overlapping efforts produce a process that is much more effective than is possible with each discipline operating independently. Because real-time geomechanics seeks to update the bounding conditions of the downhole pressure operating windows, collaborative workflows are structured around validation and calibration of the real-time geomechanical model. Collaborative workflows are presented for specific operations during the well construction process in which NPT events are likely to occur, such as tripping out of the hole and drilling. In the examples, real-time calculated equivalent circulating density (ECD) models, hole cleaning parameters, swab pressure models, and torque/drag plots provide input to the real-time geomechanical model. Outputs of this analysis are actionable recommendations, such as an extended flow check, check trip, or mud weight increase. The workflows were developed based on lessons learned from information in a central database and the resulting best practices from multiple deepwater wells. Decision makers are provided with data-supported recommendations at crucial junctures; these recommendations typically involve costly rig time. The trade-off between increased rig time and benefits gained from the recommendation is difficult to quantify. The workflows derived from a library of NPT events address the perception of wasted rig time and provide context to real-time interpretations. Combined plots supporting the recommendation provide confidence for the driller that the increased rig time is time justified.