The Vacuum oil field was discovered in Lea County, New Mexico in 1929 on the northwest shelf of the Permian basin.
Vacuum cumulative production, primarily from the Permian age Grayberg and San Andres dolomites, totals more than 600
MMBO and 800 BCF gas from 2400 wells at 4200 to 4800 feet.
Enhanced Recovery Project
A research project organized through the Colorado school of Mines, using multiple 3-D seismic surveys and multiple
geochemical surveys, evaluated both tools for tracking hydrocarbon movements in an enhanced recovery project on the Vacuum
oil field. Results of the seismic portion of the project are available
here. The orange box shows the one square mile area
studied for this project. The structure, below, is the map generated from the multiple 3D seismic surveys. The six CO
2 injectors
are shown along with two established faults and two probable faults. This same structural map is overlaid on the "net change"
geochemical survey maps below.
Stucture contour map based on the top of the San Andres. Interval, 100 feet. Roy Milks (1957) and the Roswell Geologic Society.
The first net change map shows a pronounced sweeping of hydrocarbon away from the injectors and down the structure both to
the north and south. The hydrocarbons are also moving away from the injectors to the east and west but they are moving
towards the highs.
Survey 1 Baseline 3/98
Survey 2 10/98
Survey 3 10/99
Net Change Iodine, Survey 1 to Survey 2
Net Change Iodine, Survey 1 to Survey 3
Lea County, New Mexico
Vacuum Oil Field
Survey 1 Baseline 3/98
Iodine Survey Results
The first survey, below (3/98), was before any CO2 injections and represents a baseline to evaluate the next two surveys. The
baseline iodine data indicated substantial anomalies (remaining hydrocarbons) associated with this elderly Field. If we use the
baseline survey as a measure of subsurface hydrocarbons at each sample location then other than analytical error the differences
between the baseline and subsequent surveys should be the net change in underlying hydrocarbons. If a reading goes lower the
hydrocarbons have moved away, if values increase hydrocarbons have moved to that location. The "net change maps" should
represent the subsurface hydrocarbon movements responding to the CO
2 injections.
The net change map for the baseline to the third survey is very similar to the first net change map. The swept areas to the
north have remained much the same, to the south there are few increases south of the fault The areas around the injectors is
largely swept with the exception of the southwest injector with a very high value on a possible fault. Most of the increases in  
hydrocarbons are now on or very close to the structural highs.
These surveys have established real time relationship between soil iodine and subsurface hydrocarbons. Geochemical surveys
should be a useful tool to monitor hydrocarbon movements associated with CO
2 enhanced recovery projects.  
GrayStone Exploration Labs, Inc
GrayStone Exploration Labs, Inc