EEG 335: Petroleum Geology and Geophysics Winter Term 2024
Woodford SCOOP shale play Geosteering Exercise
*When exiting the SES Program, always navigate back to the Main Menu screen and press “Exit.”
Geosteering Introduction
Geosteering software such as SES is generally viewed as a tool used for keeping horizontal wells in a specific target zone, using real-time data to interpret subsurface stratigraphic well location and make decisions while drilling. However, geosteering software can also be used post-drilling to supplement an operator’s regional structural and stratigraphic understanding of a play, to develop stratigraphic correlation across a basin, to learn the process of geosteering, and to evaluate how effectively the well the penetrated the objective section (assuming a given distance that can be fracked). With geosteering software like SES, operating geologists use MWD and LWD data (in this case gamma ray log data) to interpret the location of a lateral well bore with respect to surrounding stratigraphy.
SES Explained
Following the workflow from the provided SES Workflow document, geologists use well survey data, type log data, and LWD gamma ray log data in tandem with maps and seismic data to determine the location of a wellbore relative to surrounding stratigraphy. After the well is “kicked” from vertical, the operations geologist communicates their interpretation of the data to the drilling engineer to ensure that the well stays “in section.” Using the SES geosteering software, the geologist can communicate information such as when the wellbore jumps a fault or when apparent dip of beds begins to change.
In the real world, seismic data, structure maps, and thickness maps are used to develop expectations of what the wellbore might encounter in the subsurface. Use the provided structure and isochore maps to get an idea of what trends to expect when interpreting the data in SES. Such as, what the nominal dip magnitude and azimuth should be.
The Assignment
Well 1 will be done in class. You will complete Well 2 on your own. I strongly suggest you work on this second well before class on Wed so you can ask questions at the beginning of class.
Your task is to interpret well data from the Woodford SCOOP shale play in Oklahoma’s Anadarko basin. The data provided are on R:\courses\Geo 335-Petroleum 2024\SES Geosteering Project and include the following data for three wells:
Inspect all of these data before you begin. Get a sense of what the structure is, what is the dip, where the wells are, etc. Jot down a few sentences about your observations, and what you should expect in the subsurface.
We are going to steer two wells depending on our time constraints. One, a simple horizontal well (Woodford SCOOP Well 1), and the other a slightly more structurally and stratigraphically complex well (Woodford SCOOP Well 2), both of which are found in the R: drive location referenced above.
Copy and Paste SES Geosteering Project folder to your (Q:) folder and then follow the instructions for the “SES Workflow” document.
To be turned in by Friday Mar 8, for each well:
A cross section of your steered well, and a one-page description that addresses summarizes the general structure, and how the effectively well stayed within the target interval (payzone). Also, of the general dip and what distance the frac would need to reach away from the well bore to reach the payzone and the broader objective section (the given stratigraphy UW2 through LW).