Software Research And Application For Natural Gas Hydrate Seismic Identification

With the shortage of traditional energy sources,such as petroleum and natural gas,gas hydrate is recognized as an ideal alternative energy of fossil fuels in the future. Its identification technology research and software development for evaluating the potential gas hydrate exploration is very necessary. However, the existing commercial software cannot distinguish gas hydrate effectively and reliably. And relying on the reflection characteristics of seismic wave is ambiguous and limited. Seismic multi-attribute identification technology need to be done.Response characteristics of the gas on seismic is not separable, but a related unity macroscopically. Affected seismic attributes or response characteristics from deep to shallow are as follows: the quality factor (permeability), coherence, elastic parameters(transverse wave and longitudinal wave,density),feather flow. A software system needs to be developed to estimate these attributes and present these results, and make comprehensive comparison with seismic data. These can detect the actual underground gas effectively, which is helpful to analyze the spatial distribution of natural gas hydrate,and can provide scientific reference for seismic exploration.As a part of gas-hydrate identification team, my research is summarizing new methods of hydrate identification worked out by team members, eventually compiling these methods into software system to make the theory and method applied practically.The software system can be applied to conventional seismic data inversion. Based on ratio of p-wave increment to s-wave velocity increment method and AVO inversion method of primary software systerm, seismic multi-attribute inversion method was added,namely methods of interlayer quality factor,elastic parameters,and coherence.In addition,during actual operation, some primary software modules do not meet the demand for new projects, so they need to be improved in the light of their defects, the structures and functions of software need to be redesigned in order to be more practical.The operation of seismic data also needs to be improved ,actualizing the extension from 2d seimic data to 3d data,which is not ony the demand for projects, but also the demand for analyzing hydrate accumulation in a wide range . Human-computer interaction and the display of inversion results also needs to be improved further. Therefore, based on the Qt platform,I developed a set of natural gas hydrate seismic identification software with varied functions, easy operation and high efficiency. Functions between modules and modules complement each other, which become an analyzing system from submarine strata, seafloor to seawater, dedicating to the identification of gas hydrate.