PetroChina's Chuanqing Drilling Breaks National Record For Coal, Rock And Gas Horizontal Wells

Recently, the Ningtan 1H well drilled by PetroChina Chuanqing Drilling Team 70516 was successfully drilled to a depth of 5,470 meters. The deepest vertical depth of this well reaches 4071.49 meters, setting a new national record for the deepest vertical depth of a coal gas horizontal well, laying a solid foundation for the efficient development of coal gas wells in Sichuan and Chongqing.

Drilling crew members inspect drilling tools. Photo courtesy of Chuanqing Drilling

Coalbed methane is a kind of unconventional natural gas. The industry usually identifies coalbed methane with a vertical depth of more than 1,500 meters as deep coalbed methane. my country is rich in coalbed methane resources, especially deep coalbed methane which has broad prospects. However, due to the more complex geological conditions of deep coalbed methane, with characteristics such as deep burial, high in-situ stress, and strong plasticity, development is more difficult. Currently, the Sichuan and Chongqing areas are still in the early stages of exploration.

This year, Chuanqing Drilling has identified the "Unconventional Gas Revolution Project" as one of the "Top Ten Projects" and will use this as a guide to accelerate the improvement of well engineering operation capabilities and service efficiency.

Well Ningtan 1H is the first coal gas risk exploration well deployed in Southwest Oil and Gas Field. The well was drilled on July 31, 2023, with a horizontal section of 1,000 meters. The well faces the well-developed coal and rock section of the Longtan Formation, with active oil and gas displays and high well control pressure; the coal seam box is narrow, the coal gangue layer in the interlayer has complex lithology and poor drillability; the formation inclination angle changes greatly, the well trajectory is tortuous, and the coal and rock Problems such as easy collapse.

The drilling team employees completed the construction tasks safely and efficiently. Photo courtesy of Chuanqing Drilling

During the construction, Chuanqing Drilling dispatched experts to track and guide throughout the process, constantly refining technical plans and measures, and optimizing drilling parameters; the team strictly implemented technical measures, insisted on working together with all relevant parties every day, and relied on the advantages of integrated engineering and geology collaboration to adopt large-scale drilling methods. Displacement, high speed and other means can solve complex geological problems in real time. At the same time, the team always puts well control safety first, and the on-duty cadres follow throughout the entire process, effectively preventing underground complications and ensuring that the well is drilled efficiently and safely.

The industry believes that the successful completion of Well Ningtan 1H not only opened up a new situation in coal, rock, gas and oil and gas exploration in the Sichuan and Chongqing areas, but also provided important reference and valuable experience for subsequent coal and rock gas well construction.