When an oil field has been exploited for nearly 30 years, what else can it rely on to sustain its life? The answer given by BP in the ACG oil field in Azerbaijan is not to find new oil fields, but to drill through multiple reservoirs with one well.

Technological breakthrough of the most mature oil field in the Caspian Sea

BP and Azerbaijan SOCAR have recently completed the landing of two key technologies in the ACG oil field. One is to apply a 1.1-kilometer horizontal naked eye tube in the B18W well of the Central Azerbaijan Platform, in conjunction with advanced drilling and completion technology, to initiate non associated gas production operations; Secondly, the first multi branch well C44 in the Caspian Sea was delivered from the West Azerbaijan platform.

Multi branch well technology allows drilling multiple reservoirs from a single wellbore, directly solving the dual constraints of drilling complex formations in ACG and tight platform space. The first MLT well had zero safety accidents and was completed 30 days ahead of schedule. The drilling and completion efficiency exceeded expectations, providing a strong commercial justification for the promotion of the entire oilfield.

From single well testing to system deployment

BP has clarified the follow-up rhythm. C44 and D41 wells will be put into operation in the first half of 2026, and another well will be launched within the year, with a total of three MLT wells leading the way; Continue to expand deployment scale from 2027 to 2028. However, BP also emphasized that no single MLT scheme can cover all reservoir conditions. In the future, multi branch wells will be combined with horizontal drilling, intelligent completion, sand control, and inflow management technologies to match the optimal configuration for different geological targets. The joint venture partners also include MOL, Inpex, ExxonMobil, TPAO, and ONGC Videsh, and multi-party collaboration has reduced the risk exposure of technology promotion.

The logic of ACG oil fields represents a common shift in mature oil fields around the world: the increase in installed capacity is at its peak, and the real increment lies in further improving the recovery rate of existing assets. Multi branch wells are not a new technology, but their first application in the highly complex and spatially constrained environment of the Caspian Sea is a clear signal - the second half of mature oil fields is not about scale, but about technological density.Editor/Cheng Liting