Application of Seismic Attenuation Attribute for Gas-bearing Sandstone Reservoir Detection

摘要

It is known that,natural gas produces much less sulfur dioxide and nitrous oxides than any other fossil fuel such as coal or petroleum,so it is a type of cleaner energy.In recent years,China has increased the percentage of natural gas steadily in her energy consumption and the environmental reward will come soon.For example,this effort contributes a lot to more bright-blue days in 2008 Olympic host city,Beijing.The demand of natural gas will definitely accelerates in China and this will promote more efforts for gas exploration and development,which provides substantial support to reduce pollution and reestablish our environment.Currently the industry exhibits an extensive interest in lithology gas reservoirs,especially the gas-bearing sandstone reservoirs which have abundant potential gas resources.However,lithology reservoirs appear more implicit to geophysical surveys than structural reservoirs.In recent years,a number of successful cases proved that the seismic wave attenuation attribute,which can indicate oil and gas accumulation underground,has played a significant and irreplaceable role in lithology gas reservoir predicting.In this paper,the model based study method is adopted.Based on several hypotheses which have been developed to try to explain seismic attenuation effects,we present a new 2D geologic model containing gas-bearing reservoirs.After the seismic record synthesizing,data processing and attenuation attribute extracting,the numerical experiment shows that seismic energy attenuated dramatically while propagating through gas-bearing sandstone blocks comparing to its surrounding rocks.Then the attenuation attribute is derived from a 3D field seismic data from northeastern Sichuan Province,China.By investigating the seismic attenuation anomalies of field data and those of synthetic data,we could see the magical power of attenuation technology.All this work would show us a vivid picture that seismic attenuation attributes could help human being to detect more nature gas underground effectively.