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
The first deep well in China's offshore world was successfully put into production at 9,508 meters
Recently, CNOOC Limited announced that China's first self-designed and implemented ultra-deep and extended-reach well, Well A1H of Enping 21-4 Oilfield, was successfully put into production in the Pearl River Estuary Basin, with a daily test output of more than 700 tons of crude oil. The well has a drilling depth of 9,508 meters and a horizontal displacement of 8,689 meters, becoming the deepest well in China's offshore and setting a record for the horizontal length of drilling in China, marking that China has successfully overcome the technical bottleneck of 10,000-meter-level extended-reach wells, and the technical level of offshore ultra-far and ultra-deep drilling has entered the forefront of the world.
The Enping 21-4 oilfield developed by this ultra-deep well is located about 200 kilometers southwest of Shenzhen, with an average water depth of about 86 meters. CNOOC Limited uses the Enping 20-5 unmanned platform 8 kilometers away to implement ultra-deep and extended reach wells, which can efficiently develop oil and gas resources in marginal oilfields.
Extended-reach wells are cutting-edge technologies that challenge the limits of drilling, and are also one of the technical problems recognized by the global industry. Enping 21-4 oilfield A1H well water vertical ratio of 4.43, equivalent to every 1 meter step, to take a big stride of nearly 4.5 meters, drilling tools in the lack of gravity propulsion, must rely on external driving force through more than 8,000 meters.
Guo Yongbin, chief engineer of CNOOC Shenzhen Branch, said that extended-reach wells are an important means of efficient exploration and development of oil and gas resources in complex areas such as oceans and mountains, and the ultra-deep extended-reach wells in Enping 21-4 oilfield have refreshed 4 national records, formed 13 technical achievements in 5 categories, and the localization rate of materials and equipment used has reached 95%. Relying on this model, oil and gas resources can be used within 10,000 meters of the production platform in the future, which can significantly improve the development efficiency of oil and gas fields.
According to statistics, in recent years, about 350 extended-reach wells have been drilled offshore China, with a drilling footage of 1.745 million meters, which is equivalent to drilling through nearly 200 Mount Everest. The operation scale, average aging, maximum water gravity ratio, and target quality are all in the forefront of the world.
Text: Reporter Dong Pengcheng Translation: Shi Yangyi