The White House announced today that President Carter will nominate Frank C. Carlucci, the U.S. ambassador to Portugal, to become deputy director of the Central Intelligence Agency.

The choice of Carlucci, 47, former director of the Office of Economic Opportunity in the Nixon administration, is expected to help ease internal friction in the CIA that has been brought about by implementation recently of a reorganization plan.

But first the nomination will have to be approved by the Senate. Earlier this year, Carter selected Carlucci to be deputy under secretary of state for management, to succeed Richard M. Moose.

But that nomination ran into opposition from some congressional Democrats, partially because of Carlucci's role as OEO director and later deputy director of the Office of Management and Budget in the Nixon administration.

The selection of Carlucci ends the White House search for a No. 2 man who was a veteran civil servant. The CIA director, Adm. Stansfield Turner, is a career military man. Under law, if the CIA director is a military officer, the deputy director must be a civilian.

The reorganization plan that has spawned some turmoil in the agency was put into effect last August, when, in response to an order by Turner, the agency began reducing the number of overseas agents. The reductions are designed to bring more younger persons into the agency gradually and to increase the chances for promotions.

The White House also announced today that Richard J. Bloomfield, ambassador to Ecuador, would be nominated to replace Carlucci in Portugal. Bloomfield, 50, is a native of Derby, Conn. He has been the U.S. representative in Ecuador since 1976. e hazard is not great, she said.