Abstract: The gravel-packing sand control technology applied in offshore in China originated from foreign companies, which has become unified after years of developments. Conventional 7" casing wells have a bore diameter of 3.25" after completion of sand control. Although it is possible to realize a multi-layer high-speed water filling, fracturing and filling operations cannot be performed, and the small internal diameter after well completion limits the implementation of later layered injection and production operations. The new single-pass multilayer gravel packing technology is based on conventional sand control technology, and it improves the tool structure, expands the outer diameter of the service tools, increases the fracturing capacity of the filling operation, meets the needs of various on-site processes, and achieves the inner diameter of 3.88" after completion of sand control, which finally facilitates the smooth implementation of subsequent operations.