An offshore drilling platform in the South China Sea. Photo: Xinhua

A submarine pipeline at a depth of 1,542 meters on the south side of the E3-E2 sections of the Lingshui 17-2 gas field has been successfully completed, marking a breakthrough for China in deep water gas field exploitation in the South China Sea.

The Lingshui 17-2 gas field - the first deep water field established by a Chinese company - is located in the South China Sea near South China's Hainan Province. 

The operational depth of the field, which is also the China National Offshore Oil Corporation's (CNOOC's） first self-operated deep water field, is 1,220-1,560 meters with trillions of cubic meters of exploitable gas reserves.

The field is expected to be operational by the end of China's 13th Five-Year Plan (2020). It will have an annual gas output of 3-5 billion cubic meters, which could promote the exploitation of deep-water gas resources.

Submarine pipeline is the main artery that transports oil and gas and is regarded as the lifeline of the offshore oil and gas production system. 

Three hundred meters below sea level is considered to be deep water and 1,500 meters is known as ultra deep water. Due to the complex and changeable submarine environment, constructing an ultra deep water submarine pipeline is a challenge, it also has strict requirements on the pipeline's quality and size. 

Prior to the construction of the Lingshui field, ultra deep water submarine pipelines were mostly built by foreign countries.