The Royal Dutch-Shell group, parent of the Houston-based Shell Oil Co., yesterday reported its 1979 earnings rose 181 percent above previous year levels.

Royal-Dutch Shell had profits of $6.8 billion in 1979 versus $2.4 billion in 1978. Revenues were up 19.2 percent to $66.1 billion from $53.8 billion.

U.S. dollar amounts are translated from British pounds at the exchange rate of one pound equalling $2.23.

Royal-Dutch Shell said its earnings surge reflected a sharp escalation in oil prices, currency translations and the strengthening of the British pound. These factors added about $2.5 billion to its net income last year before the start of the first-in first-out method of inventory accounting.

With these factors eliminated, the company said net earnings were up only about 31 percent from 1978.

Royal-Dutch Shell said its capital and exploration expenditures totaled $9.87 billion last year, of which 74 percent went to the search for and development of oil and natural gas.

Included under 1979 expenditures was $3.75 billion spent by Shell Oil for the purchase of Belridge Oil Co. Under terms of the acquisition, former Belridge shareholders have the option for a limited period of buying an interest of up to 44 percent in Belridge's former oil and gas properties.