Integrated 3-D Real-Time Visualization of Reservoir Navigation Model, 3-D Seismic Cube and While-Drilling Inversion of Ultra-Deep Azimuthal Resistivity

Abstract

Abstract

Optimizing well placement in today's complex reservoirs requires new technology. To optimize the use of this new technology, complimentary real-time workflows and software are required.

Through presentation of a case study from an offshore well in Brazil, this paper describes a new application and methodology which allow quicker, and more informed well placement decisions to be made.

The initial reservoir navigation objective for the well was to delineate the top and the base of the reservoir while maintaining the wellbore in the pay zone for a 1000 meter interval, using a pre-well geosteering model based on seismic data, and inversion of ultra-deep azimuthal resistivity measurement while drilling. The new workflow proposed was to compare the geosteering model and bed position information derived from rig-site inversion of ultra-deep resistivity measurements with the seismic model in a 3D visualization tool to allow real-time interpretive updating of the seismic model. Integrating the reservoir navigation and geophysical workflows while drilling significantly reduces the time taken versus a more conventional sequential workflow. It also reduces the 3D geospatial model uncertainty by incorporating the latest interpretive revisions, such as faults or formation dip changes. This collaborative interpretation ultimately means that a risk to the planned well objectives can be identified and mitigated more efficiently.

The new workflow resulted in an updated seismic interpretation in real time, allowing early replanning of the optimum well trajectory based on early identification of a 10 m vertical shift in TVD if, and a 5 degrees formation dip change compared to the initial seismic model. In this case, a 600 meter reservoir section was drilled, successfully steering and mapping the reservoir architecture. The well was stopped when the OWC hardline was reached.

AAPG Datapages/Search and Discovery Article #90260 © 2016 AAPG/SEG International Conference & Exhibition, Cancun, Mexico, September 6-9, 2016