Bohai offshore oil and gas area was formed by onshore Liaohe depression, Huanghua depression, seaward extension part of Jiyang depression and Bozhong depression, covered 51 thousand sq. km . Bohai oil and gas fields covered 58.327 thousand sq. km and ranked the second largest among the oil production areas in China, its energy resource ranked the first largest in China.

Oil and gas exploration was started from seashore of Huanghua depression, 72 oil and gas fields or oil-bearing and gas-bearing structures have been found, it is a Teriary sedimentary basin rich in oil and gas resources, also is the major oil and gas production base in China with oil and gas resource 7.67 billion tons and 27.2 billion cubic meters relatively. At present, proven oil and gas reserve are 860 million tons OOIP and 27.2 billion cubic meters OGIP. The major oilfields are Huanzhong36-1, Qinhuangdao32-6 and Penglai19-3.

The development of Bohai offshore lead China ocean petroleum development, including 96 functional oil and gas area, in 2000, accumulative oil and gas production were 6.5345 million tons and 855.93 million cubic meters relatively from total 832 productive wells. The turnover was accumulated to about RMB1.085849 billion Yuan.

Exploration was initiated in 1958, ten oilfields and nearly 20 oil and gas bearing structures have been found in Haisi, Yuanbei, west428, east428, 427, Bozhong28-1, Bozhong34-2, Bozhong34-4, Huanzhong36-1 oilfields and Jinzhou20-2 condensate oilfields with OOIP and OGIP 300million tons and 20 billion cubic meters relatively. In 1988, annual oil and gas production were 410 thousand tons and 13.87 million cubic meters. Thus it can be seen that Bohai oilfield has been formed the first offshore oilfield in China with primary scale.

Penglai19-3 oilfield is located north part of western Liaohe depression with low uplift, downstream of Liaodong bay, Bohai basin, is also located in Liaodong bay of Bohai.

Oil and gas exploration was initiated in 1959, Jinzhou20-2-1 structure favorable structure in the new digital seismic interpretation. Jinzhou20-2 condensation gasfield was discovered by natural gas and condensation oil flow from Jinzhou20-2-1 well on the high of Jinzhou20-2 on Dec.5, 1984. At the end of Dec., 1984, controlled oil-bearing area was 14.4 sq. km, OOIP was 4.52 million tons. Penglai19-3 is the largest oilfield in China.

Jinzhou20-2 condensate gas field is locate north part of western Liaohe depression of low uplift, downstream of Liaodong bay, Bohai basin, is also locate in Liaodong bay of Bohai.

Oil and gas exploration was initiated in 1959 , Jinzhou20-2-1 structure is a favorable structure in the new digital seismic interpretation. Jinzhou20-2 condensation gasfield was discovered by natural gas and condensation oil flow from Jinzhou20-2-1 well on the high of Jinzhou20-2 on Dec.5, 1984. At the end of Dec., 1984, controlled oil-bearing area was 14.4 sq. km , OOIP and OGIP and condensate reserve were 4.52 million tons and 13.54 billion cubic meters and 3.327 million tons relatively. Jinzhou20-2 is condensate gas field with high production and pressure in come scale in China.

Huanzhou36-1 oilfield is located middle part of western Liaohe depression by low uplift in Liaodong bay downstream, Bohai basin, also is located in the sea area of Liaodong bay, 50km west from Huanzhong town, Liaoning province, 102km far from Qinhuangdao city, Hebei province.

Exploration in Liaodong bay was initiated in 1959, Huanzhong oilfield was discovered by industrial oil flow from Huanzhong36-1-1 well. At the end of Dec.1997, controlled oil-bearing area was 43.3 sq. km hold 288.44 million tons OOIP, it’s the offshore oilfield with the biggest reserve in China.

Bohai is a sedimentary basin rich in oil and gas resource, offshore oilfield along with onshore oilfields such as Shengli, Dagang and Lioahe formed the No2 oil production region in China. Bohai offshore lead to the development of ocean oil and gas in China. Among the six big ocean sedimentary basins, Bohai is the earliest oilfield to initiate geophysical exploration, with the most amount of drilling wells, fixed production platform is account for more than ninety percent in the similar platform in China. Yuanbei oilfield the first offshore oil production base constructed by international standard, its production been sable at the first place in offshore oilfields in China.