THE DISTRIBUTION OF GAS CHIMNEY STRUCTURES IN SHENHU AREA AND THEIR INFLUENCE ON GAS HYDRATE ACCUMULATION

Many seismic indicators of gas hydrate and free gas,such as BSR (Bottom Simulating Reflector), bright reflection under BSR and chimney structures,have been found in the Shenhu area by seismic survey. The distribution of BSR is consistent with chimney structures. Chimney is believed the main migration path of the pyrolysis gas from deep sediments. The pyrolysis gas originated in the deep hydrocarbon source rock is transported to HSZ(Hydrate Stability Zone),which offers favorable conditions for massive gas accumulation, through chimneys. Therefore, it is significant to learn the distribution of chimney structures for understanding the distribution and accumulation pattern of the gas hydrate in the Shenhu area. The traditional method recognizes chimney structures only by use of seismic data based on weak reflection,columnar shape and related attributes. This paper comprehensively and efficiently analyzed the distribution of chimney structures with the method of neural network based on the MLP (Multi-Layer Perception) algorithm. The influence of chimney structure on gas hydrate accumulation is interpreted by integration of BSR distribution and regional tectonics.