China National Petroleum Corporation CNPC's Shendi Chuanke 1 oil well, located in Jiange County, Southwest China's Sichuan Province. Photo: CMG

As China National Petroleum Corporation (CNPC) achieved a drilling depth of over 10,000 meters at one of its wells, it marked a significant step forward in the nation's exploration of deep-earth energy resources, China Media Group reported on Wednesday.

On Wednesday morning, the Shendi Chuanke 1 Well, located in Jiange County, Southwest China's Sichuan Province, reached this milestone under extremely complex geological conditions, the media report said. 

This deep-earth "mega project," which involves highly challenging drilling conditions, has penetrated 23 strata and reached the Sinian Formation dating back 540 million years, marking the first time drilling has entered the deep "no-go zone" of the Sichuan Basin.

When describing the technical challenges of ultra-deep drilling, the report noted that formations below 7,000 meters in the area remain completely unknown, making the process akin to "opening a blind box." Temperatures exceeding 200 degrees Celsius underground cause metal drilling tools to become "as soft as noodles," while formation pressures surpass 130 megapascals—equivalent to the weight of more than a dozen elephants pressing on an area the size of a fingernail.

The project has brought back samples that dispel earlier assumptions that oil and gas could hardly be trapped in the region, confirming that the deep layers of the Sichuan Basin still possess favorable storage conditions and hold vast exploration potential.

Traditionally, strata below 8,000 meters were considered unsuitable for oil and gas accumulation due to extreme heat and pressure. However, analysis of Sinian rock cores retrieved from a depth of more than 9,500 meters revealed "pores, cavities, and fractures with well-developed reservoirs。"

Shendi Chuanke 1 Well is the second over 10,000-meter-deep borehole in China after the Shendi Take 1 Well in the Tarim Basin in the Northwest China's Xinjiang Uygur Autonomous Region, according to CNPC.

Launched in July 2023, Shendi Chuanke 1 Well is the first scientific exploration well in the Sichuan Basin to reach 10,000 meters. It aims to explore unknown domains of Earth science, forge major national capabilities in deep-earth drilling, and serve as a source of original technologies for oil and gas exploration and development.

Global Times