Year-on-year, the level of new drilling activity in Texas in November was down by more than half, a state regulator reported.

The Railroad Commission of Texas, the state energy regulator, said it issued 687 new drilling permits last month, against the 1,508 issued last year. Of those, the bulk of original permits were for oil or gas, with about a quarter going specifically for oil.

As of Friday, oil services company Baker Hughes recorded 333 rigs actively exploring for or producing oil and natural gas in Texas, a number that represents about 45 percent of all rigs in service inland in the United States.

Oil production in Texas for September, the last full month for which data are available, was 83.3 million barrels, down about 8 percent from the previous month for the second straight month of decline. Year-on-year, however, the daily production rate of 2.4 million barrels is 10 percent higher than for September 2014.

The U.S. oil sector is faltering under the strain of the long slump in crude oil prices, which are down about 45 percent from this time last year. Texas, however, has shown some resiliency during the downturn, with federal reports showing shale basins in the state among the few expected to record stronger rates of production next month.

Nevertheless, the Texas Petro Index, a metric used to gauge the health of the state's energy sector, declined for the 11th straight month in October, the last full month measured by the index.

The Dallas Federal Reserve last week said some parts of the state economy were performing better than the rest of the nation, though wages and employment prospects continued to falter as lower crude oil prices become the new normal.