Relief well planning can be a critical safety measure, ensuring readiness and rapid response in the event of a catastrophic blowout that threatens human life and the environment. Recent regulatory changes in the oil industry have spurred a demand for extensive relief well planning for shelf and deepwater wells around the world. This paper discusses well planning, trajectory design, and drilling as it applies specifically to relief wells.

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In January of 2008, Shell began drilling an extended reach exploration well from the Mars tension leg platform (TLP). This was an ambitious undertaking with targets nearly 20,000 ft (6,096 m) away in an unexplored fault block. Because of the high inclination of the borehole and the shallow depth of the objective sands, any geological uncertainty in the targets jeopardized the success of the project.While surface seismic is used to evaluate potential targets, it lacks the resolution needed to reliably place those targets. Different seismic processing techniques are available, but the validation of each model requires additional information. True vertical depth (TVD) and true vertical thickness (TVT) synthetic ties created from realtime logging data can improve that resolution. By employing a method that uses TVT, the synthetic ties better match the seismic model allowing for updates to the well path and precise placement inside the target. Multiple velocity models are also incorporated to obtain better time-to-depth relationships and to better predict pore pressure anomalies.In extended reach wells, small issues in the beginning can escalate into more serious problems at total depth. The well path, dogleg severity, and casing shoe placements must be optimized, leaving room for the possibility of changes due to unexpected events. Bottom hole assembly (BHA) design is also a key success factor. Acquiring the needed information in realtime to update the seismic model, while also factoring in tool reliability and planning for shoe-to-shoe performance, is critical. Further, at these high angles, it is important to drill a smooth and continuous borehole to reduce torque and allow for better casing runs. This paper describes how the geological, mechanical, and economical uncertainties were identified and minimized through well planning and the use of realtime data. Specifically, this paper addresses those uncertainties, associated risks, and the methods to minimize them in the A-8 well.The authors examine the pre-well work undertaken with the seismic data and how the BHA and well plan were designed to allow for possible changes. In addition, they will discuss how all the data were used to continually update the model and reduce geologic uncertainty as the targets were approached. Answers were provided in time to update the well path, increasing the chances for success, and ultimately meeting the well objectives.

With well depths more commonly surpassing 30,000 ft below the mudline and ever-increasing water depths, exceedingly high-pressure environments present a new and challenging frontier for both operators and service companies. These new environments demand advances to existing technology to endure such pressure extremes while also accurately positioning the wellbore in the reservoir and obtaining critical geological information as the well is drilled. A recent example in this pressure regime in the deepwater Gulf of Mexico will be reviewed. Pressure limits of the currently available technology are extended while successfully meeting drilling and evaluation goals. The drilling and evaluation technologies delivered real-time formation pressure and geological information, along with continuous directional control, enabling the operator to make vital decisions while drilling and for sidetrack evaluation. This real-time decision-making capability reduced the time required to execute casing point selection and subsequent sidetrack plans. Emphasis is placed on the need for operators and service companies alike to focus on thorough pre-job planning while paying close attention to complete system requirements high-pressure evaluation tools and detailed reviews. Newer drilling opportunities, particularly in the deepwater arena, involve operating in extreme environments such as ultrahigh pressures, and demand different approaches to ensure flawless execution. This paper presents the variety of challenges, critical success factors, and lessons learned when drilling these ultra-high pressure wells in the demanding waters of the Gulf of Mexico. With downhole pressures approaching 30,000 psi and ever-increasing rig costs, the need for dependable drilling systems and integrated advanced formation evaluation technology is needed now more than ever. The case results showcase the ability to set a new performance standard, extend the conventional operating envelop farther, and deliver answers while drilling.

In these times of record operating costs, stakeholders place paramount importance on avoiding unnecessary, unproductive trips in the well. In well intervention applications such as milling, cutting, washing over and casing exit work, the lack of accurate information about downhole conditions often leads to wasted time and money. As wells become deeper, more tortuous and technically challenging to intervene, the need to know more about what is actually occurring at the downhole tools becomes even more critical. Traditional surface-based indicators and gauges often provide inaccurate readings of the forces exerted at and around downhole tools. This paper discusses a new, MWD-style "smart" intervention performance sub that contains a variety of sensors and electronics that gather critical downhole measurements and transmit them to surface. The smart tool affords the operator a completely new level of control with real-time decision-making capabilities that can lead to more efficient and reliable wellbore intervention jobs and significantly reduce operators' risk exposure. The paper will describe the smart tool and present several case histories where the smart intervention performance sub was integrated into well intervention bottomhole assemblies. Data from the smart tool was then transmitted using mud pulse telemetry and viewed at surface. The same data was also transmitted onshore to a real-time operating center, thus allowing a broader audience of experts to witness the early field trial applications. The field trials verified several capabilities. Vacuum filter operation could be observed in real time, casing windows could be quantified with a window quality indicator, lightweight fish could be identified in real time at the bottom of deep, deviated wells, and packer setting forces and overpull could be accurately monitored downhole in a variety of depths and deviations. This summarizes the capabilities explored during deepwater system integration tests. Introduction Well intervention jobs are specialized, often critical, operations performed by experienced and well-trained tool experts. The more critical the operation, the more accurate this statement, and never more so than when conducting casing exit and fishing operations such as multilateral (ML) junction creation, milling, cutting, and washing over. Complex well intervention operations of a critical nature bring with them an inherent element of risk. The nature of this particular risk is that unseen sub-surface conditions and events can manifest themselves as unplanned non-productive time (NPT) with potentially severe consequences for fiscal prudence. Well intervention operations cover a huge expanse of well and rig activities. The processes and techniques discussed here, however, are not yet sufficiently advanced to be applied across the whole gamut of operations, so in the context of this paper, the term "well intervention" will apply to workover systems; fishing and milling, including packer setting and recovery; casing exit systems [sidetracking or junction creation], and wellbore cleanup. Well intervention operations are traditionally performed using surface-acquired parameter measurements such as RPM and hook load; complemented by a tool expert's sense of feel and anticipation. It is well known that the industry is entering a period where such experience is becoming scarce. These factors, combined with ever-increasing well reach and complexity, act to increase the risk to wellbores. Drilling, on the other hand, has benefited from new technologies that optimize complex well construction to the extent that, compared to only a few decades ago, drilling operations have evolved into highly efficient and predictable processes. It is this drilling optimization technology that has been adapted to form the basis of a new smart intervention system that boosts performance by allowing downhole parameters to be displayed at surface to enable real-time decision-making and full process optimization in well intervention operations.