4月13日，我国首口自主设计实施的海上超深大位移井 — 恩平21-4油田A1H井在距离深圳200公里的珠江口盆地海域投产，测试日产原油超700吨。请看本报16日报道：

China’s first independently designed ultra-deep large-displacement well, the Enping 21-4 oilfield A1H well, has commenced operations. The well is located about 200 kilometers southwest of Shenzhen in the South China Sea and has a tested daily production capacity of over 700 tons of crude oil.

The Enping 21-4 oilfield, where the ultra-deep well is located, has an average water depth of about 86 meters and is classified as a small sandstone marginal oilfield.

文中的marginal oilfield指的是一些中、小型油田或地层构造复杂及地处边远的油田。由于储量有限、该地区缺乏基础设施以及开发成本过高，这些油田通常仍未开发。