Photo: Xinhua

With a depth of 9,026 meters, the Pengshen-6 in Southwest China's Sichuan Province has set a new record for the deepest vertical gas well in Asia. 

The completion of the drilling and cementing on Monday indicates that China's drilling equipment and technology hold leading positions in Asia and have reached world-class levels, industry insiders said.

The well, located in the Penglai gas area in Sichuan's Yanting county, is a key pre-exploration well, aiming to explore the development and gas-bearing property of the reservoir at a depth of 8,000 meters, according to chinanews.com.

The Penglai gas area is an important future natural gas production base in the Sichuan Basin. Additional storage capacity of 1 trillion cubic meters is basically in place, according to Sichuan local media outlet Scol.com.

The well was drilled by a subsidiary of China National Petroleum Corp (CNPC) in July 2021. The original design depth of the well was 7,990 meters. In order to further explore the oil and gas properties in the deep stratum, the drilling depth was eventually increased to 9,026 meters.

Industry insiders call it an "underground Mount Qomolangma," also known as Mount Everest.

"The depth is a record for the deepest vertical well in Asia, which provides a strong engineering and technical guarantee for ultra-deep oil and gas exploration in China," Ma Yong, a deputy director of the Engineering Technology Department at CNPC Southwest Oil & Gasfield Co, said.

The geological conditions of the well are complicated, and they pass through more than 10 different strata. The drilling faced challenges such as extreme depths, temperatures, pressure levels and sulfur content.

For instance, the minimum drilling hole diameter of the Pengshen-6 well is 15 centimeters. At a depth of more than 9,000 meters, such a small drilling space is a great test for the precision control of drilling.

Ma said that the drilling of the Pengshen-6 well has laid a good foundation for the 10,000-meter-deep exploration well to be implemented in 2023.

In the practice of oil and gas exploration and development, strata buried more than 8,000 meters belong to the super-deep category. 

Since 2011, CNPC has completed eight super-deep wells with depths surpassing 8,000 meters and two ultra-deep wells over 9,000 meters in the Sichuan Basin. 

Global Times