Layer | Fill | Outline |
---|
Map layers
Theme | Visible | Selectable | Appearance | Zoom Range (now: 0) |
---|
Fill | Stroke |
---|---|
Collaborating Authors
Results
Geomagnetic Referencing in the Arctic Environment
Poedjono, Benny (Schlumberger) | Beck, Nathan (Schlumberger) | Buchanan, Andrew (Eni Petroleum Co.) | Brink, Jason (Eni Petroleum Co.) | Longo, Joseph (Eni Petroleum Co.) | Finn, Carol A. (U.S. Geological Survey) | Worthington, E. William (U.S. Geological Survey)
Abstract Geomagnetic referencing is becoming an increasingly attractive alternativeto north-seeking gyroscopic surveys to achieve the precise wellbore positioningessential for success in today's complex drilling programs. However, thegreater magnitude of variations in the geomagnetic environment at higherlatitudes makes the application of geomagnetic referencing in those areas morechallenging. Precise, real-time data on those variations from relatively nearby magneticobservatories can be crucial to achieving the required accuracy, butconstructing and operating an observatory in these often harsh environmentsposes a number of significant challenges. Operational since March 2010, theDeadhorse Magnetic Observatory (DED), located in Deadhorse, Alaska, was createdthrough collaboration between the United States Geological Survey (USGS) and aleading oilfield services supply company. DED was designed to produce real-timegeomagnetic data at the required level of accuracy, and to do so reliably underthe extreme temperatures and harsh weather conditions often experienced in thearea. The observatory will serve a number of key scientific communities as well asthe oilfield drilling industry, and has already played a vital role in thesuccess of several commercial ventures in the area, providing essential, accurate data while offering significant cost and time savings, compared withtraditional surveying techniques.
- Geology > Sedimentary Geology (0.94)
- Geology > Rock Type > Sedimentary Rock > Clastic Rock (0.69)
- Energy > Oil & Gas > Upstream (1.00)
- Government > Regional Government > North America Government > United States Government (0.73)
- North America > United States > Alaska > Schrader Bluff Formation (0.99)
- North America > United States > Alaska > North Slope Basin > Western North Slope > Canning Formation (0.99)
- North America > United States > Alaska > Nikaitchuq Field > Schrader Bluff Formation (0.99)
Successful Application of Geomagnetic Referencing for Accurate Wellbore Positioning in a Deepwater Project Offshore Brazil
Poedjono, Benny (Schlumberger) | Montenegro, Diana (Schlumberger) | Clark, Pete (Chevron Corporation) | Okewunmi, Shola (Chevron Corporation) | Maus, Stefan (Magnetic Variation Services and CIRES, University of Colorado) | Li, Xiong (Fugro Gravity & Magnetic Services)
Abstract Accurate wellbore positioning is a major challenge in the Frade field, a deepwater heavy oil project offshore Brazil that has been historically technically and economically challenging. The inherent subsurface and surface complexities alone might have prevented the development of this asset, as the structure is a low-relief anticline with two main fault blocks, consisting of three stacked reservoirs, and spanning an area of 20 km. The key challenge in magnetic surveying in Brazil is the large discrepancy between downhole tool readings and the British Geological Survey (BGS) Global Geomagnetic Model (BGGM), which provides the magnetic field at a 400-km resolution. A better understanding of natural variations in the local magnetic field is essential for a successful development of the field. As such, a new method of mapping the natural variations was developed. With its recent refinements, geomagnetic referencing can now produce significant savings in overall project cost by providing accurate, real-time data on wellbore position while corrections to trajectory are still possible, preventing the costly sidetracks often required when errors are discovered in a post-drilled survey. It can also eliminate the need for costly troubleshooting of downhole magnetic tools in real time, caused by inaccuracy of the geomagnetic model used. This paper outlines collaboration among operator, contractors and academic experts, and the development of the High-Definition Geomagnetic Model (HDGM) by the United States National Geophysical Data Center, which improves the spatial resolution to 30 km. The large-scale magnetic field study was integrated with the Bacia de Campos aeromagnetic survey to account for the entire spatial spectrum of the geomagnetic field, down to the kilometer scale. Using ellipsoidal harmonic functions and an equivalent source technique, two 3D geomagnetic references were produced for comparison purposes, and the results were validated by observations from the downhole measurement-while-drilling (MWD) tool reading.
- North America > United States (1.00)
- South America > Brazil > Rio de Janeiro > South Atlantic Ocean (0.26)
- South America > Brazil > Rio de Janeiro > South Atlantic Ocean > Campos Basin > Area do 1-RJS-366 > Frade Block > Frade Field (0.99)
- South America > Brazil > Campos Basin (0.99)
- Well Drilling > Well Planning > Trajectory design (1.00)
- Well Drilling > Drilling Measurement, Data Acquisition and Automation > Measurement while drilling (1.00)
- Reservoir Description and Dynamics > Reservoir Characterization (1.00)
- Data Science & Engineering Analytics > Information Management and Systems (1.00)
High Definition Geomagnetic Models: A New Perspective for Improved Wellbore Positioning
Maus, Stefan (NOAA’s National Geophysical Data Center and CIRES, University of Colorado) | Nair, Manoj C (NOAA’s National Geophysical Data Center and CIRES, University of Colorado) | Poedjono, Benny (Schlumberger) | Okewunmi, Shola (Chevron Corporation) | Fairhead, Derek (GETECH) | Barckhausen, Udo (German Federal Institute for Geosciences and Natural Resources) | Milligan, Peter R. (Geoscience Australia) | Matzka, Jürgen (Techical University of Denmark)
Abstract Earth’s gravity and magnetic fields are used as natural reference frames in directional drilling. The azimuth of the bottomhole assembly is inferred by comparing the magnetic field measured-while-drilling (MWD) with a geomagnetic reference model. To provide a reference of sufficient quality for accurate well placement, the US National Geophysical Data Center (NGDC), in partnership with industry, has developed high-definition geomagnetic models (HDGM), updated regularly using the latest satellite, airborne and marine measurements of the Earth’s magnetic field. Standard geomagnetic reference models represent the main magnetic field originating in the Earth’s liquid core, but the new models additionally account for crustal magnetic anomalies, which constitute a significant source of error in directional drilling. NGDC maintains a public archive of global ship and airborne magnetic field measurements. These are compiled into a global magnetic anomaly grid and expanded into ellipsoidal harmonics. The harmonic expansion coefficients are then included in the high-definition models to accurately represent the direction and strength of the local geomagnetic field. The latest global model to degree and order 720 resolves magnetic anomalies down to 28 km half-wavelength, achieving more than an order-of-magnitude improvement over previous models. A side-by-side comparison of different on- and off-shore regions shows the high level of local detail represented in the new model. Accounting for a larger waveband of the geomagnetic spectrum significantly improves the accuracy of the reference field. This directly benefits the reliability of the well azimuth determination. We further demonstrate that model accuracy is a prerequisite for applying drill string interference corrections. Finally, an accurate reference model facilitates the validation of MWD surveys by keeping the field acceptance criteria centered on the true downhole magnetic field. Together, these factors improve well placement, prevent and mitigate the danger of collision with existing wellbores and enable real-time steering to save rig-time and reduce drilling costs.
- Europe (1.00)
- North America > United States > Louisiana (0.24)
- Energy > Oil & Gas > Upstream (1.00)
- Government > Regional Government > North America Government > United States Government (0.94)
- North America > United States > West Virginia > Appalachian Basin > Marcellus Shale Formation (0.99)
- North America > United States > Virginia > Appalachian Basin > Marcellus Shale Formation (0.99)
- North America > United States > Pennsylvania > Appalachian Basin > Marcellus Shale Formation (0.99)
- (3 more...)