Abstract: To address the core challenges in drilling the Paleozoic fractured limestone reservoirs of an oilfield in Bohai Sea, namely "frequent lost circulation, low rate of penetration (ROP), and coexistence of blowout and lost circulation caused by inconsistent pressure systems", an integrated technology system has been established through systematic research and field practice. This system covers "gel + bridging" composite lost circulation control, enhanced torsional impact tools, precision managed pressure drilling (MPD), and efficient handling of complex working conditions. The application of this technology in Well X has achieved remarkable results. After adopting the composite lost circulation control technology, the lost circulation rate dropped from 60～70 m³/h to 5～6 m³/h, a reduction of over 90%. With the enhanced torsional impact tools, the ROP reached 15 m/h, which was 5 times higher than that of Well Y (2.5 m/h) using simple drilling tools in the same block, and twice as high as that of Well Z (7.6 m/h) using conventional ROP-enhancing drilling tools. Additionally, the single-trip footage reached 366 m with slight bit wear. Meanwhile, the fine MPD technology effectively balanced the contradiction between blowout and lost circulation, improving the overall efficiency in terms of both operation safety and drilling efficiency. Eventually, the well was successfully drilled to the target depth, and complete and accurate geological data was acquired. This technology provides an effective technical solution for the efficient exploration of fractured limestone reservoirs and has popularization value.