1000+! China's Offshore Drilling Is World-leading!

In 2024, the total number of offshore drilling in China exceeded 1,000 for the first time, and more than 10 key technologies achieved breakthroughs. "In 2024, key indicators such as China National Offshore Oil Corporation's daily drilling efficiency, production timeliness, and downtime reached the best level in history, helping offshore oil and gas exploration and development to make significant progress." Li Zhong, chief engineer and drilling and completion expert at the China National Offshore Oil Corporation Research Institute, said. Offshore drilling and completion have the "three highs" characteristics of high risk, high cost, and high technology. Since the "14th Five-Year Plan", China National Offshore Oil Corporation has made continuous breakthroughs in drilling and completion technology, and the average annual number of domestic offshore drilling has increased by more than 60% compared with the "13th Five-Year Plan". Among the offshore drilling carried out in 2024, the Enping 21-4-A1H well created two "national bests" of the deepest offshore well depth and the largest horizontal displacement. Zhou Shouwei, an academician of the Chinese Academy of Engineering, said: "CNOOC's overall offshore drilling and completion technology has reached the world's advanced level, and some deep-sea drilling and completion technologies have also reached the world's advanced level." Thanks to the solid and optimized capacity design, CNOOC has made breakthroughs in four technical series and more than 10 key technologies to drill more than 1,000 wells offshore. Li Zhong introduced: "In 2024, CNOOC completed 13 basic drilling and completion designs throughout the year, and promoted the effective development of complex fields such as deepwater, medium-deep layers, shallow underwater, and low permeability with technological innovation and achievement transformation."

Based on the concept of "few wells and high production", CNOOC has formed a series of technologies in four aspects, namely "well type optimization, production improvement, long-term stable production, and residual oil potential tapping", and more than 10 key technologies, actively responding to the key problems faced by offshore oil and gas field development, such as stable production of producing oil and gas fields and effective development of low-quality reserves. In 2024, these key technologies will be applied to 238 single wells, helping to optimize and reduce 52 wells, and achieve an increase of 10,319 cubic meters of oil per day and 6.24 million cubic meters of gas per day. More than 1,000 offshore wells have benefited from focusing on innovation in drilling and completion technologies, "unlocking" oil and gas exploration and development in restricted waters, high temperature, high pressure, deep water, and low permeability.

In the shallow water field, CNOOC took the lead in developing a shallow water electric pump well underwater Christmas tree system, created an underwater drilling and completion operation mode under the mud surface, and applied it in Jinzhou 25-1W oilfield. By optimizing the installation process and tools, the diving time was shortened by more than 70%, providing an efficient solution for oil and gas development in restricted waters.
In the deepwater field, the blowout operation of the A12 well of the Phase II project of the "Deep Sea No. 1", the highest pressure natural gas development well in my country, was successfully completed in August 2024. The test output exceeded expectations, marking the completion of the offshore drilling and completion operations of the Phase II of the "Deep Sea No. 1", my country's first deepwater high-pressure natural gas development project. The total well depth exceeds 60,000 meters, which is nearly the height of 7 Mount Everests. The operation period is 30% shorter than the design, and the operation quality qualification rate is 100%. "In the exploration of digital intelligence in deepwater gas field development, we have cooperated with relevant units to achieve phased results in digital wellbore, near-drill bit engineering parameter measurement, intelligent drilling navigation, and intelligent wellbore construction, relying on innovative technologies to help speed up and improve the efficiency of on-site operations." Li Zhong introduced. In the field of high temperature and high pressure, China National Offshore Oil Corporation has developed offshore precise pressure-controlled drilling and pressure-controlled cementing technologies for offshore drilling and completion operations with "narrow pressure windows" such as deepwater high temperature and high pressure, ultra-high temperature and high pressure, and controlled the accuracy within 0.2 MPa, which has been successfully applied to the pressure-controlled drilling operations of Caofeidian 23-6 oilfield.

More than 1,000 offshore wells have been drilled thanks to the continuous upgrading of digital safety management and control technology. The "Sky Eye Project" deeply integrates advanced machine vision technology with drilling and completion business, and pioneered 10 drilling and completion feature video recognition scenes in China. After the technology was put into use on the "Haiji No. 1" platform, the average daily alarm number dropped from 1.55 to 0.1, effectively playing a "deterrent" role and helping the drilling and completion development project achieve the "zero accident" goal of 345,000 man-hours.
In the future, China's offshore drilling and completion will still face challenges such as arduous tasks of increasing reserves and production, severe safety risks, and digital intelligent upgrades. "In 2025, China National Offshore Oil Corporation will adhere to the concept of innovation-driven and technological leadership in the field of drilling and completion, deepen the development of fewer wells and high production, and contribute value to increasing reserves and production of marine oil and gas." Li Zhong said.