Please join GSOC for our October technical session and luncheon
Presenter: Paul Constance, Chief Geophysicist Continental Resources
Multicomponent Surface Seismic, Multicomponent VSP in Reservoir Characterization: Mississippian and Woodford - Noble, Pawnee and Payne Counties, Oklahoma
A 180 square mile multi-component 3D survey was acquired in Noble, Pawnee and Payne counties, Oklahoma to characterize the Mississippian Lime and Woodford reservoirs for unconventional drilling. The Mississippian Lime is highly fractured, karsted and faulted. The underlying organic Woodford is more homogeneous. Porosities within the Woodford vary across the project area, ranging from 6 to 14 percent.
We recorded a comprehensive suite of logs in 5 pilot wells broadly distributed across the 180 square mile project area. We took a conventional core in the George 1-23 SWD well through a complete section of the Mississippi Lime and Woodford Shale and used the results to calibrate our Petrophysical models. We recorded a densely sampled multicomponent 3D Vertical Seismic Profile (3C3DVSP) at the same time as recording the surface 3D seismic. Wealso recorded 2 Microseismic surveys. One in a lateral landed in the Miss Lime and the second in a lateral landed in the Woodford.
The goal for the project was to define the reservoir with well control and then map these reservoir parameters across the project area using surface 3D seismic. The Petrophysical data and downhole seismic (3C3DVSP) were used tocalibrate the surface 3D seismic, improving the fidelity and therefore the confidence in the results.
This paper outlines the technologies, and methods used to define a complex heterogeneous reservoir. The project demanded the integration of multi-disciplinary data to achieve its goals of calibrated reservoir definition. Many surface seismic projects are recorded mainly for hazard control; improving well landing, and avoiding faults during drilling and completions. However 3D seismic has the potential to add much more value. The first step is to define the problem, whether it’s laterally varying porosities, fracture and fault distribution, or the ‘fracability’ of the reservoir to name a few, and then determine what tools best image, identify and map these parameters. As we demand more from our seismic we have to be more exacting in how we design record and processes our seismic surveys.
The Mississippian Lime is a tight highly fractured reservoir. Our lateral FMI log in the George 1-23H recorded up to twenty fractures per foot along the lateral. The FMI’s in the verticals show that the fractures are bed limited. Sonic Scanner data in the same wells, logged velocity differences of up to 16 percent between the fast and slow shear waves due to shear wave splitting. This horizontal anisotropy correlates to zones of intense fracturing.
Understanding and mapping the fracture system within the Mississippian Lime was clearly important in planning new well locations and guiding completion methods.