Abstract:
Natural gas hydrates are widely distributed and shallowly buried in the ocean. It is clean, pollution-free, and huge in reserves. As a clean energy source, it has great development potential in the future. In order to conduct the commercial exploitation of natural gas hydrate, it is necessary to explore the efficient gas hydrate exploitation technology based on multilateral wells. In the process to use the TOUGH+HYDRATE simulator to make numerical simulation, the complex structure well modeling is the difficulty. In this paper, we proposed a fast modeling method for complex structure well based on mVIEW. Taking the multilateral well as an example, the modeling process is briefly introduced in this paper. In addition, combined with the TOUGH+HYDRATE simulator, based on the logging curve data from the testing well of SHSC-4 operated by the China Geological Survey in 2017 in the Shenhu area of the Baiyun Sag in the deep water area of the northern South China Sea, an ideal layered geological model is established for hydrate reservoirs. Single horizontal well and multilateral well numerical simulation for depressurized production in the central part of the Hydrate Layer II is conducted. The simulation results show that: The modeling method has improved the simulator's ability in complex modeling and has good effect and reference significance for the numerical simulation research work for highly efficient gas hydrate production; Compared with single well depressurization production, multilateral well technology can maximize the exposed area and depth of gas hydrate reservoirs, and effectively increase the degree of production of hydrate reservoirs. It is a technical method worthy to be developed for efficient production of natural gas hydrates in the future.