China’s second-largest oil company Sinopec has started drilling what it claims to be Asia’s deepest onshore well in the Tarim basin in northwestern China’s Xinjiang region.

The Yuejin 3-3XC well is designed to be drilled to a depth of 9472 metres, a record in Asia, the company said.

The previous record was also set by Sinopec. The Shunbei 84 well, drilled in March, reached a vertical well depth of 8938 metres. This well flowed 1017 tonnes of oil per day.

The Yuejin 3-3XC well, which was spudded on 1 May, is part of Sinopec’s Shendi 1 project being developed at its Shunbei oilfield in Xinjiang, where the average reservoir depth is 7300 metres — considered one of the deepest in the world, according to Sinopec.

The well will encounter complex geological structures, characterised by high temperatures, high pressures and a high hydrogen sulphide content, Sinopec said.

With a designed horizontal drilling distance of more than 3400 metres, the well will face challenges in casing insertion and the formation of a "rock debris bed" in the horizontal section.

For the Shendi 1 project, Sinopec has drilled 49 oil and gas wells — each with average vertical depths of more than 8000 metres.