After fourth-quarter profit dropped 23%, Asia's largest refiner ( SHI , quote ) plans to boost oil production in West China and increase exploration for unconventional resources including gas from shale formations.

The Beijing-based China Petroleum & Chemical Corporation, commonly known as Sinopec, said the strategy is aimed at countering losses from selling diesel and gasoline at state-mandated prices. China controls oil-product prices to curb inflation, raising tariffs by as much as 7.1% last year.

Sinopec wants to achieve a better balance between downstream and upstream parts of the company, say analysts, more closely resembling that of Exxon Mobil ( XOM , quote ) or Royal Dutch Shell ( RDS.A , quote ).

According to Sinopec, its production of crude and gas rose 1.6% last year to 407.9 million barrels of oil equivalent, crude output fell 1.9% to 321.7 million barrels, and gas production jumped 17%, to 517.1 billion cubic feet.

China, estimated by the U.S. Energy Information Administration to hold the world's largest reserves of shale gas, aims to produce 6.5 billion cubic meters of the fuel annually by 2015, and between 60 billion and 100 billion by the end of 2020.

With analysts estimating that unconventional oil and gas will be the main sources of growth for Sinopec's upstream business (predictions are that it will produce at least 2 billion cubic meters of unconventional oil and gas by 2015), Sinopec has already started exploring for shale gas in Anhui province with China National Offshore Oil Corp (CNOOC).

Sinopec's capital spending on exploration and production will reach CNY78.2 billion ($12.4 billion) this year as the company develops oil blocks, including Shengli, and gas fields such as Yuanba and Ordos, according to its most recent earnings statement. Spending on refining will be CNY36.8 billion, mainly to upgrade plants.

The firm also plans to acquire overseas oil and gas assets owned by its parent when appropriate it said, following the move in November by the refiner's parent company, Sinopec Group, to pay $5.2 billion for a stake in Portugal's Galp Energia to explore for oil off Brazil's coast - China's biggest overseas purchase in 2011. In 2010, the group paid $7.1 billion for a 40% stake in Repsol YPF's Brazilian unit.

The company also plans to build refineries and oil-storage bases overseas, President Wang Tianpu stated, and Sinopec Group signed an agreement with Saudi Arabian Oil Co. in January to develop a 400,000 barrel-a-day oil-processing plant in Saudi Arabia.