@ARTICLE{Dec_Jerzy_A_2012, author={Dec, Jerzy and Pietsch, Kaja}, volume={vol. 28}, number={No 3}, journal={Gospodarka Surowcami Mineralnymi - Mineral Resources Management}, pages={93-112}, howpublished={online}, year={2012}, publisher={Komitet Zrównoważonej Gospodarki Surowcami Mineralnymi PAN}, publisher={Instytut Gospodarki Surowcami Mineralnymi i Energią PAN}, abstract={In the Fore-Sudetic Monocline area, gas deposits occur in carbonate rocks of cyclothems PZ1 (Zechstein limestone Ca1) and PZ2 (main dolomite Ca2). The location of deposits is closely connected with zones of carbonate sedimentation. Generally, gas deposits occur within barrier zones and at the foot of carbonate platforms. The outburst of rock fragments into the heading of the KGHM Rudna mine in 2009 was evidence that gas could also appear in the basin zone Ca1 of the copper deposit. 2D and 3D surface seismic surveys comprise the basic method which is applied to hydrocarbon prospecting. The main advantage of this method is the fact that P-wave velocity and bulk density decrease as a result of gas saturation of the pore spaces. As a result, one can observe anomalous seismic [records(activity?)] which can be connected with gas deposits, and reservoir interpretation of seismic data is based on Direct Hydrocarbon Indicators analysis (DHI). This paper presents and compares seismic images of gas saturation [in traps(trapped?)] in a typical carbonate barrier (Kościan gas field in Ca1) at the foot of a carbonate platform (Lubiatów gas field in Ca2), and in a porous/fractured zone in Ca1 dolomite where there was a gas outburst in the Rudna mine. Based on available well logging data and 1D seismic modeling (synthetic seismograms) this study developed criteria for identification of gas-saturated zones for each case. The results of the study provide the following basic criteria for gas saturation: (1) phase change at Ca1 bottom from negative at the basin zone to positive at the barrier zone - for the Kościan barrier Ca1; (2) the bright spot at the top of the saturated zone - for the Lubiatów deposit at the foot of the carbonate platform; (3) reflections with close to zero amplitude at the bottom of Ca1 dolomites - for the porous and fractured deep-water zone of the Rudna mine.}, type={Artykuły / Articles}, title={A possibility of seismic identification of gas accumulations in zechstein carbonate formations of the fore-sudetic monocline}, URL={http://www.czasopisma.pan.pl/Content/85718/PDF/dec-pietsch.pdf}, doi={10.2478/v10269-012-0025-z}, keywords={gas deposit, seismic survey, Zechstein Limestone, seismic anomalies, Direct Hydrocarbon Indicator}, }