Recently, China National Offshore Oil Corporation (CNOOC) announced that China's first independently designed ultra-deep large-displacement well, the Enping 21-4 oilfield A1H well, has commenced operations. The well is located in the Pearl River Estuary waters and has a tested daily production capacity of over 700 tons of crude oil. It has a drilling depth of 9,508 meters and a horizontal displacement of 8,689 meters, making it the deepest well in China's seas and setting a record for the country's horizontal drilling length. This marks a successful breakthrough in the technical bottleneck of 10,000-meter-class large-displacement wells, positioning its offshore drilling capabilities among the world's leading.
The Enping 21-4 oilfield, about 200 kilometers southwest of Shenzhen, operates in waters with an average depth of around 86 meters. CNOOC has leveraged an unmanned platform "Enping 20-5", positioned 8 kilometers away, for extended-reach drilling, which can efficiently exploit the oil and gas resources of marginal oilfields.
Extended-reach wells are cutting-edge technologies that challenge drilling limits and are recognized globally as one of the most technically challenging endeavors in the industry. At the Enping 21-4 oilfield A1H well, the HD/VD Ratio reaches an impressive 4.43, which means that for every 1-meter descent, the drilling equipment needs to make a large stride of nearly 4.5 meters forward. This requires drilling equipment to traverse over 8,000 meters without the assistance of gravity, relying solely on external driving forces.
Guo Yongbin, Chief Engineer of CNOOC Shenzhen Branch, stated that extended-reach wells are crucial for efficiently exploring and developing oil and gas resources in complex regions such as the ocean and mountainous areas. The Enping 21-4 oilfield's ultra-deep extended-reach well has set four national records and yielded five categories of 13 technological achievements, with 95% of the materials and equipment used being domestically produced. This model has the potential to unlock oil and gas resources within a 10,000-meter radius of production platforms, significantly enhancing the efficiency of oil and gas field development.
According to statistics, China has implemented approximately 350 extended-reach wells offshore in recent years, with total drilling footage of 1.745 million meters, equivalent to drilling through nearly 200 Mount Everest. This places China at the forefront of the world in terms of operational scale, average efficiency, maximum HD/VD ratio, and target accuracy.
Source :Yangcheng Evening News
9508米！中國海上第一深井順利投産
近日，中國海油宣布，中國首口自主設計實施的超深大位移井——恩平21-4油田A1H井在珠江口盆地海域順利投産，測試日産原油超700噸。該井鑽井深度9508米，水準位移8689米，成為中國海上第一深井，同時創造中國鑽井水準長度紀錄，标志着中國成功攻克萬米級大位移井技術瓶頸，海上超遠超深鑽井技術水準跨入世界前列。
該超深井開發的恩平21-4油田位于深圳西南方約200公裡的海域，平均水深約86米。中國海油利用8公裡外的恩平20-5無人平台，實施超深大位移井，可以高效開發邊際油田的油氣資源。
大位移井是挑戰鑽井極限的尖端科技，也是全球行業公認的技術難題之一。恩平21-4油田A1H井水垂比達4.43，相當于每下一個1米的台階，就要往前邁出近4.5米的大跨步，鑽具在缺少重力推動下，必須依靠外部驅動力穿行8000多米。
中國海油深圳分公司總工程師郭永賓表示，大位移井是高效勘探開發海洋、山地等複雜地帶油氣資源的重要手段，此次恩平21-4油田超深大位移井重新整理4項全國紀錄，形成5類13項技術成果，使用的材料、裝備國産化率達95%。依托該模式未來可實作在生産平台1萬米範圍内的油氣資源動用，顯著提高油氣田開發效益。
據統計，近年來中國海上實施大位移井約350井次，鑽井進尺達174.5萬米，相當于鑽穿近200座珠穆朗瑪峰。作業規模、平均時效、最大水垂比、中靶品質等均居于世界前列。
文｜記者 董鵬程翻譯｜史洋溢