Oil explorers expanded drilling in U.S. fields for the first time this year as rising crude prices buoyed optimism.

Working U.S. oil rigs rose by 10 this week to 862, according to data released Friday by oilfield-services provider Baker Hughes (BHGE.N). The hike in rigs only partially reversed the worst setback for American exploration in almost three years.

Crude has climbed about 25 per cent since Christmas Eve, restoring some confidence among management teams and wildcatters rattled by a steep, fourth-quarter collapse. Halliburton Co. (HAL.N), the world’s biggest fracker, earlier this week forecast a modest increase in demand for its services during the current quarter, although the Houston-based company warned it probably won’t be able to raise its prices.

“As our customer budgets reload in the first quarter, they are going back to work,” Halliburton CEO Jeff Miller told analysts and investors during a Jan. 22 conference call. “Despite a slow start, 2019 will be another year where we continue to build the foundation for a longer-term recovery.”

U.S. crude producers are pumping a record 11.9 million barrels a day, according to the Energy Information Administration.