MADISON (AP) — The city of Madison has filed a trespassing charge against affiliates of a Texas-based oil company that is in Madison County surveying for carbon dioxide that could be used to increase oil production.

Crews working for Denbury Resources have set up seismic survey equipment across the county from Flora to the Ross Barnett Reservoir.

The company is using controlled blasts to create an underground map of potential CO2 pockets, but Madison Mayor Mary Hawkins Butler said the city never granted permission for crews to use its rights of way.

Denbury geophysics manager Bob Schellhorn says the risks involved with this type of testing are “extremely small.”

If CO2 is found, it could be pumped to dead oil fields to make them produce more oil.

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