On June 23, 2022, CNPC successfully drilled to a depth of 9,010 meters in Well Shuangyu 001-H6 in the Southwest Oil and Gas Field, setting a record for the deepest gas well onshore in China.

Well Shuangyu 001-H6 is located in Guangyuan City, Sichuan Province. It is an ultra-deep, ultra-high temperature and ultra-high pressure horizontal well. The well temperature exceeds 180 degrees Celsius, the formation pressure exceeds 130 MPa, and the hydrogen sulfide content reaches 6 grams per cubic meter.

During the construction of the horizontal section of Well Shuangyu 001-H6, the drill bit was extended from the ground to 9 kilometers underground through a drilling tool. It is no less difficult to control a 149.2 mm diameter drill bit 9 kilometers away to walk along the reservoir, as difficult as threading a needle 100 meters away. Chuanqing Drilling relies on advanced and mature directional well technology, and the wellbore trajectory in the horizontal section is smooth and stable.

Drilling fluid is known as "drilling blood" and affects the success of drilling operations. Chuanqing Drilling adopts the self-developed oil-based drilling fluid system that is resistant to high temperature and strong plugging. In horizontal well drilling, the wellbore is stable without collapse, the maximum well deviation is 92.16 degrees, and the maximum well temperature is 180 degrees. At the same time, we creatively explored the use of oil-based drilling fluid system with high temperature resistance and strong plugging and solid lubricant glass microbeads to successfully solve the problem of directional depressurization in ultra-deep wells.

The breakthrough of 9,000 meters has overcome complex geological problems such as "ultra-high temperature, ultra-high pressure, and ultra-well depth", providing valuable experience for the development of drilling engineering technology.Editor/Ma Xue