Drilling wells to depths >25,000 ft will continue to present geologic and economic challenges for deepwater operators. These capital-intensive projects require acute attention to maximizing drilling efficiency and mitigating risk. Using several case studies, this paper describes recent deepwater subsalt exploration activity and discusses the challenges of drilling through the salt. Through close collaboration between the operator and drilling service provider, efforts to push rig and tool limitations successfully resulted in an increase in drilling efficiency. Additionally, extensive job planning, close monitoring of drilling parameters and continual testing against modeled data during execution were shown to address uncertainties seen below the base of salt. This paper takes lessons from multiple wells and presents an approach to: Improve drilling penetration rates in salt by means of vibration mitigationAchieve early detection of base of saltModel and integrate design (BHA) components for optimum drilling performanceValidate structural dip and improve upon the geologic seismic model using real-time LWD imaging.

This paper discusses the successes and lessons learned during the first deployment of a High Speed Telemetry Drill Pipe Network with a Rotary Closed Loop System (RCLS) and Triple Combo suite in North America. The paper details the operational experience while drilling a lateral well with an emphasis on drilling optimization and LWD processing; given the ability to receive real-time, memory quality, data via a telemetry drill pipe network. Recent advances in Logging While Drilling technologies call for broader bandwidths and faster telemetry data rates for full utilization of data available downhole. In addition to the improvements in LWD technologies, there has been a remarkable development of downhole drilling dynamics and optimization tools. A telemetry drill pipe network that delivers real-time memory quality data at 57,000 bps transmission rates, provides a step change in capability for the industry - dramatically changing the decisions that can be made in real-time. The major lessons learned during the project were i. Real-time monitoring is a valuable tool for controlling and mitigating dynamic dysfunctions downhole resulting in immediate ROP improvements; ii. High volume of real-time memory data imposes new challenges on surface software systems; iii. High resolution bore hole images via telemetry drill pipe facilitate real-time on-site dip picking and analysis of downhole conditions; iv. Handling of telemetry drill pipe at surface plays a key role in improving the efficiency of overall drilling operation. With a telemetry drill pipe network, the present generation of drilling engineers can have high quality down-hole dynamics information and mechanical specific energy (MSE) data real-time while drilling. Likewise, the geologists and petrophysicists can have access to 8 sector gamma images and 16 sector density images, real-time via telemetry drill pipe. The success of the project has provided the industry with an impetus to pursue this technology as a ground-breaking path towards making real-time informed decisions while drilling. Introduction Increasing drilling and completions costs are pushing oil companies to look for innovative technologies that can offset economic forces associated with challenging environments. High Speed Telemetry Drill Pipe or Wired Pipe Telemetry is an emerging technology that has the potential to revolutionize exploration and development drilling by optimizing the overall drilling and completions process. A telemetry drill pipe network has successfully demonstrated data transmission rates of 2 megabits per second in testing facilities (Jellison et al. 2003) and 57,000 bits per second in several field trials (Manning et al. 2007). The data rates demonstrated by this technology are significantly higher than the standard Mud Pulse Telemetry (8 to 12 bits per second). Electromagnetic telemetry can deliver rates up to 100 bits per second but still is nowhere close to the bandwidth available with high speed telemetry drill pipe network. The first deployment in North America of the high speed telemetry drill pipe network was in conjunction with an RCLS and a triple combo logging suite of a leading MWD/LWD service provider. Previous deployments of this technology with RCLS / LWD / Triple Combo include the Troll Field, North Sea, where two extended lateral wells were drilled, and in off-shore Myanmar, where a commercial well was drilled for pressure management (Hernandez et al. 2007).

No abstract

In deepwater and other challenging environments, operators often have to drill through ‘problem zones.’ These zones could be rubble zones, tar zones, or just unstable pressure zones. In the past, operators often had to drill through these areas, lose drillstrings, and drill a sidetrack, hoping that they might be able to avoid these areas the second time. But with the advancement of steerable drilling liner systems, we now have a solution in place to tackle the toughest drilling challenges. With much of the equipment coming from field-proven technologies, the next generation of steerable liner systems is increasingly proving to be the answer to reducing nonproductive time. This technology will allow operators to drill well sections directionally with the liner string as part of their normal drilling operations and case off that section all in one trip. This paper highlights these steerable liner systems and illustrates their ability to outperform conventional casing while drilling systems.

With the world's dependence on hydrocarbon-based energy sources driving global demand, new drilling opportunities require technological innovation to increase efficiencies and optimize production. Some newer drilling operations, particularly in the deepwater arena, involve extreme environments such as ultra-high 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 Gulf of Mexico's demanding waters. With downhole pressures approaching 30,000 psi and escalating rig costs, the need for dependable rotary steerable systems (RSS) along with advanced formation evaluation technology is needed now more than ever. With well depths surpassing 30,000 ft below the mudline and increasing water depths, ultra-high-pressure requirements present a new and challenging frontier for both operators and service companies. These new environments demand advances to existing technologies' operational limits 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. In cases, pressure limits of the currently available technology are extended while successfully meeting drilling and evaluation goals. 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 pressure ratings, high-pressure tool inventory management and detailed reviews. As always, communication is one of the critical success factors to ensure success. The drilling and evaluation technologies delivered real-time formation pressure and geological information, along with continuous directional control, allowing operators to make vital decisions while drilling. This real-time decision-making capability reduced the time required to execute casing point selection and subsequent sidetrack plans. Additionally, by following an application-based philosophy to technology selection, critical drilling and evaluation questions were answered in real time, reducing risks for nonproductive time (NPT) in these extreme environments. The case results showcased the ability to set a new performance standard, extend the conventional operating envelope, and deliver answers while drilling. Introduction The deepwater environment and the potential for large hydrocarbon discoveries have driven technology innovation for a substantial period of time. Advances in rig design, downhole tools, data communications and dozens of others have all rested on the challenges associated with pushing and extending limits. Considering only the drilling of a deepwater well, the associated problems are quite substantial. Throw in a variety of additional complications: a large volume of salt, geologic uncertainty, directional work in excess of 25,000 ft TVD, and a final TVD in the area of 33,000 ft, and one has an extensive set of obstacles to overcome (Fig. 1). It is critical to determine how to effectively surmount these problems rather than adopting an attitude of resignation and concluding that "it can't be done." How does one push the limits of technology while managing the known risks, extend the limits of technology and mitigate the "suspected" risks, and build a model for success?