JINAN, Dec. 18 (Xinhua) -- Powered by intelligent technologies, China's Shengli Oilfield has achieved the capability to drill shale oil wells to depths almost 6,000 meters in just 17.7 days. The drilling periods were 29.5 days in 2023 and 48 days in 2022.

The Shengli Oilfield, under China Petrochemical Corporation (Sinopec Group), the country's largest oil refiner, achieved this breakthrough by using an intelligent drilling fluid monitoring system and smart drill bits.

During shale oil extraction, high drilling pressure can create cracks in the formation, causing well leakage. Conversely, insufficient pressure may allow underground oil, water, or gas to escape, potentially leading to a blowout.

Drilling fluid is essential for maintaining well pressure, but controlling its density remains a significant challenge.

"In the past, workers typically relied on experience to adjust the density of drilling fluid," said Lu Feng, a drilling expert at Shengli Oilfield.

"Today, the intelligent drilling fluid monitoring system can promptly and accurately detect blowouts and well leaks, providing vital data to on-site personnel to ensure construction safety," Lu added.

The monitoring system also records the conditions of various geological strata, which saves manpower and improves efficiency.

"The intelligent drilling fluid monitoring system functions like an AI-powered mud engineer, tirelessly working 24 hours a day without error," said Liu Yanyan, a member of the drilling team at Shengli Oilfield.

The intelligent drilling monitoring system operates alongside smart drill bits, which can accurately assess and analyze deep formation conditions.

According to Huang Zhe, project leader for smart drill bits, the team developed a prismatic array structure to effectively minimize interference.

To enhance data projection, Huang and his team introduced physical constraint correction data, significantly reducing projection errors.

"We also developed a multi-objective evaluation model for drilling parameter schemes based on the information-sharing strategy of bird predation. This allows for rapid and efficient collection of shared information," Huang explained.

During drilling, operators can generate the optimal parameter route for the fully automatic drilling machines, avoiding downhole risks and improving drilling efficiency.

The smart bits, independently developed by Huang's team, have been applied at the Shengli Oilfield.

Shale oil mainly refers to liquid hydrocarbons that are trapped in formations of shale rock that can be extracted for refining. It is often found in organic-rich shale and thin interlayers of carbonate rocks, sandstones and siltstones.

According to official data, China's crude oil output reached 208 million tonnes in 2023, while shale oil production surpassed a record-high 4 million tonnes.

The country has established three national-level shale oil demonstration zones in Xinjiang Uygur Autonomous Region, Heilongjiang Province and Shandong Province.