(ECNS) — A shale oil well in northwest China's Xinjiang Uygur Autonomous Region was completed in 7.75 days, setting a national record for the shortest drilling cycle among shale oil wells of comparable depth, CCTV News reported.

A shale oil well in northwest China's Xinjiang Uygur Autonomous Region. (Photo: CCTV news)

Located in the Jimsar National Continental Shale Oil Demonstration Zone, the well reached a measured depth of 5,501 meters and a true vertical depth of 4,031 meters. According to the report, its drilling efficiency ranks among the international leaders for comparable shale oil wells.

Jimsar shale oil is considered particularly difficult to extract because of strong reservoir heterogeneity and complex interbedded mudstone formations, which can cause wellbore instability and downhole sticking.

The successful drilling marks a major advance in coordination among geologists, drilling crews, the project operator and contractors. It also offers a practical model for drilling deep shale oil wells in China more quickly and efficiently.

(By intern Wu Jingjing)