Houston-based drilling giant ConocoPhillips is making a play in Louisiana’s portion of the Austin Chalk formation, raising the prospect of a resurgence of onshore drilling activity in the state.

Already EOG Resources, another Houston company, has drilled a test well in the formation, which stretches across Texas through the middle of Louisiana.

The formation had little leasing activity here for two decades until the past year or so.

In that time, a handful of companies — Conoco being the latest with its lease announcement this week — have established positions in Louisiana going from the Texas line eastward through Avoyelles, the Felicianas and beyond Baton Rouge.