"碳酸盐岩油储" can be translated into English as "carbonate rock oil reservoir" or "carbonate oil reservoir".
Here, "碳酸盐岩" (tàn suān yán yán) refers to carbonate rocks, which are a type of sedimentary rock composed mainly of carbonate minerals. "油储" (yóu chǔ) means oil reservoir, which is a geological formation containing significant amounts of oil that can be extracted.
Therefore, combining these two terms, we get "carbonate rock oil reservoir" or the more concise "carbonate oil reservoir" to describe an oil reservoir hosted in carbonate rocks.