The number of rigs used in exploration and production in Texas declined, resulting in layoffs in the oil field services sector, the Dallas Federal Reserve said.

The Dallas bank released its so-called Beige Book, noting employment in most industries held steady or increased in March. Oil field services companies like Schlumberger, however, were cutting staff in response to a slowdown in the energy sector.

"Oil and gas producers and oilfield service firms continued to cut their workforce as low oil prices forced deeper cost cutting, although many contacts expressed confidence that industry employment declines will be temporary," the bank said. "Shortages of skilled construction workers persisted."

The national unemployment rate remained at 5.5 percent for March. For mining and the oil and gas sector, the rate was 8 percent.

A report last week from Bentek, the forecasting unit of energy news agency Platts, found oil production in the Permian basin in Texas has increased 50 percent in the last three years. For natural gas, production is up 30 percent during the same period.

While other reserve basins are seeing a decline in rig activity, Bentek said the Permian shale has shown resiliency in the era of low oil prices.

The Beige Book reported rig count and demand for oil services declined, however, in the Permian and Eagle Ford shale basins. While most firms surveyed by the Dallas Federal Reserve said they'd be able to weather the storm, the slump should continue through the year.

"Outlooks remained negative for 2015, with an expected 30 to 40 percent drop in capital expenditures," the bank said.

Texas is the No. 1 oil producer in the United States.