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Using diamond saw wire could cut the seabed oil compound pipes. There are different advancing velocities according to the material of pipes; it makes the cutting and advancing velocities under the condition of harmony at the time of cutting the compound pipes underwater. First of all, the experiment system of diamond saw wire was set up by test cistern, equipment of diamond wire saw underwater, hydraulic pressure system, measuring and controlling system, diamond saw wire and single layer seabed oil compound pipes so on. Next, the cutting parameters, which include pipe sizing, working pressure, tensioning force of diamond saw wire, cutting velocity and advancing velocity were initialized and the first experimentation was done. Then, after adjusting the cutting parameters according to the analysis of cutting test, the next cutting experimentation underwater was done. In the end, the wearing capacity of diamond beads was measured and got the optimal advancing velocity which can minish the wearing capacity and prolong the cutting time of diamond beads. So, using these cutting parameters to cut the seabed oil compound pipes validated the feasibility of engineering application.

Through the combination subject of scientific research, the design method of the winch driven by contactless magnetic coupling is researched for the core purpose of the turning shaft sealing in a deepwater environment. This method has six design phases, including domestic and foreign information query and retrieval, graphic analyses of relevant structures, innovative design of 2D assembly sketches, a theoretical computation of structure parameters, the 3D modeling and motion simulation and engineering drawing. This method is of generality, which can provide examples for the postgraduate students and engineering personnel in self-renovation design of scientific research.

The disadvantages of the traditional steel clamp include installation difficulty, a short service life. Therefore, a non-metallic clamp was designed to relieve these issues. MFE711 bisphenol-A epoxy vinyl resin was identified as the matrix materials needed to meet the requirements of corrosion resistance, impact resistance and other performances. After analyzing the wave load on the clamp, the resultant force on the cable protection pipe is 78784N, and its maximum equivalent stress is 73.78 MPa. This is less than the value of 155 MPa of yield strength on the clamp; therefore it meets the predetermined design requirements. Presently, there are 11 Clamp products that have been installed on the standing pipe under the offshore platform and will apply widely to engineering.