URUMQI, June 4 (Xinhua) -- After a day's work, the uniform of Li Sijiu, an worker at Zhundong oil production plant in northwest China's Xinjiang Uygur Autonomous Region, was still clean.

This was unimaginable before new eco-friendly equipment was developed and put into operation in the plant, he said.

"Our uniforms used to be stained with crude oil and wax after a day's work, and sometimes the uniforms could even stand up by themselves after being taken off due to the viscous crude oil," Li added.

Located in Zhundong Oilfield in Junggar Basin, the plant has developed a series of equipment to mitigate the impact of oil exploitation on the environment since 2015.

"We have reduced the emissions of pollutants during oil exploitation by over 90 percent through new technologies for disposal of oily sludge and automation of workover operations," said Xie Jianyong, deputy head of the plant.

Since 2016, the plant has invested more than 10 million yuan (1.56 million U.S. dollars) in developing automated workover operations and other technologies, he added.

The Zhundong plant has applied for more than 33 patents and set three operational standards in the field of eco-friendly technologies.

The plant aims to achieve zero pollution and cut the energy consumption by one-third in five years, according to Xie.

In the Northwest Oilfield near Taklimakan Desert, where the environment is extremely fragile, oily sludge, one of the major toxic pollutants during oil exploitation, has been turned into uncontaminated soil which can be used to pave roads thanks to a series of eco-friendly technologies.

"Pollutants containing cadmium and other poisonous heavy metals emitted during oil exploitation can severely pollute the soil if they are not dealt with properly," said Gu Minhe, deputy head of environmental protection

department at the oilfield.

The oil content of the oily sludge could be reduced to 2 percent using the eco-friendly disposal technology, which helps save 45 million yuan in the cost of pollutant control every year, he added.

PetroChina Tarim Oilfield Company has invested 218 million yuan to construct a 436-km-long shelterbelt along the desert road in the Tarim Basin over more than 10 years. The company also completed the construction of more than 1,300 hectares of afforested areas in the oilfield.

Since 2017, Zhundong oil production plant closed a total of 284 oil wells in the Kalamayli Nature Reserve, which is home to various endangered animals including Przewalski's horse, a first-class national protected animal. The plant will also dismantle the wells and restore the environment by the end of 2018.

"Though the efforts to protect the environment would cost the plant more than one billion yuan, we must take the responsibility for the whole society as a state-owned enterprise," said Wang Ning, Party chief of the plant.