SWN Resources was granted the extension in the Court of Queen's Bench in Fredericton on Monday, just hours before its existing injunction was set to expire.
The company said that the injunction, which includes a buffer zone around their equipment, has been effective but it needs more time to complete its work.
It cited security concerns — namely, recent protests that have resulted in arrests — and poor weather in their arguments.
The company has not yet completed all of its seismic testing along Highway 11.
An anti-shale gas protest near Rexton turned violent in October when police enforced an injunction to halt the blockade of a SWN equipment compound.
Forty people were arrested and six police vehicles burned.