Estimation of petrophysical parameters is an important issue of any reservoirs. Porosity, volume of shale and water saturation has been evaluated for reservoirs of Upper Assam basin, located in northeastern India from...Estimation of petrophysical parameters is an important issue of any reservoirs. Porosity, volume of shale and water saturation has been evaluated for reservoirs of Upper Assam basin, located in northeastern India from well log and seismic data. Absolute acoustic impedance(AAI) and relative acoustic impedance(RAI) are generated from model based inversion of 2-D post-stack seismic data. The top of geological formation, sand reservoirs, shale layers and discontinuities at faults are detected in RAI section under the study area. Tipam Sandstone(TS) and Barail Arenaceous Sandstone(BAS) are the main reservoirs,delineated from the logs of available wells and RAI section. Porosity section is obtained using porosity wavelet and porosity reflectivity from post-stack seismic data. Two multilayered feed forward neural network(MLFN) models are created with inputs: AAI, porosity, density and shear impedance and outputs: volume of shale and water saturation with single hidden layer. The estimated average porosity in TS and BAS reservoir varies from 30% to 36% and 18% to 30% respectively. The volume of shale and water saturation ranges from 10% to 30% and 20% to 60% in TS reservoir and 28% to 30% and 23% to 55% in BAS reservoir respectively.展开更多
Well log responses can be used to delineate coal and carbonaceous shale from other non-potential litho-units by cross-plotting technique. The cross-plotting between gamma ray and density had been carried out for 15 we...Well log responses can be used to delineate coal and carbonaceous shale from other non-potential litho-units by cross-plotting technique. The cross-plotting between gamma ray and density had been carried out for 15 wells of Jharia coalfield, India. Through these different cross-plots across the study area, different litho-units like;coal, shaly coal, carbonaceous shale, shale, sand/sandstone, shaly sand, jhama and igneous intrusion (mica peridotite) have been identified. Clustering of points for different lithologies in the above cross-plots indicate that the different trends with marginal overlap between carbonaceous shale/shaly coal and shale as well as shaly sand and shale. The coal horizons are mostly overlain and underlain by shale or sandstone. Cross-plot analysis indicates the various coal lithologies which will play important role in CBM exploration and exploitation strategy.展开更多
基金funding the project (MoES/P.O. (Seismo)/1(273)/2015)
文摘Estimation of petrophysical parameters is an important issue of any reservoirs. Porosity, volume of shale and water saturation has been evaluated for reservoirs of Upper Assam basin, located in northeastern India from well log and seismic data. Absolute acoustic impedance(AAI) and relative acoustic impedance(RAI) are generated from model based inversion of 2-D post-stack seismic data. The top of geological formation, sand reservoirs, shale layers and discontinuities at faults are detected in RAI section under the study area. Tipam Sandstone(TS) and Barail Arenaceous Sandstone(BAS) are the main reservoirs,delineated from the logs of available wells and RAI section. Porosity section is obtained using porosity wavelet and porosity reflectivity from post-stack seismic data. Two multilayered feed forward neural network(MLFN) models are created with inputs: AAI, porosity, density and shear impedance and outputs: volume of shale and water saturation with single hidden layer. The estimated average porosity in TS and BAS reservoir varies from 30% to 36% and 18% to 30% respectively. The volume of shale and water saturation ranges from 10% to 30% and 20% to 60% in TS reservoir and 28% to 30% and 23% to 55% in BAS reservoir respectively.
文摘Well log responses can be used to delineate coal and carbonaceous shale from other non-potential litho-units by cross-plotting technique. The cross-plotting between gamma ray and density had been carried out for 15 wells of Jharia coalfield, India. Through these different cross-plots across the study area, different litho-units like;coal, shaly coal, carbonaceous shale, shale, sand/sandstone, shaly sand, jhama and igneous intrusion (mica peridotite) have been identified. Clustering of points for different lithologies in the above cross-plots indicate that the different trends with marginal overlap between carbonaceous shale/shaly coal and shale as well as shaly sand and shale. The coal horizons are mostly overlain and underlain by shale or sandstone. Cross-plot analysis indicates the various coal lithologies which will play important role in CBM exploration and exploitation strategy.
