Research And Application Of Seismic Characterization For Formation He8of Sulige Gas Field

In this paper, the largest gas filed in China, Sulige has been studied. The main gas reservoir, known as He8formation, is located between3200and3600m in depth and is interbedded with sand and shale. Because the reservoir is thin (15-35m), strongly anisotropic and water bearing in partial area, it is a great challenge for seismic characterization.Integrated techniques of seismic characterization for He8formation has been researched in this paper. The poststack, prestack and multicomponent seismic technique of seismic characterization is selected according to the quality of seismic data. The workflow of seismic prediction for main channel, lithology and fluid is set up.The poststack techniques of waveform analysis, poststack seismic impedance inversion and DHI have been applied for prediction of main channels.Aiming at the geological conditions, the sensitive factors for lithlogy and fluids have been selected through detailed seismic rock physics analysis of full wave logging data. The effective AVO attributes has been selected. The sensitive elastic impedance invertion has been proposed for water and gas identification. The elastic invertion based on partial stacks or prestack gathers has been applied due to data conditions. The workflow for prestack seismic characterization has been set up.Conventional one-component P wave exploration has difficulty differentiating lithology and identifying subsurface fluids, However, the accuracy of the integration of both PP and PS data can be improved by using the multicomponent (MC) method. The AVO of PS data has been thoroughly studied. The integrated techniques of MC seismic attributes analysis, joint invertion of PP&PS have been applied to enhance the prediction.The integrated techniques of P-wave and MC data have been applied in Sulige gas field and have been supported with real data.