Near Surface Investigations using Reflection Seismic and VSP Measurements in the Ekeby District, Southern Sweden
Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
The Ekeby district is located in Östergötland County in south – central Sweden. In October 2012 both Vertical Seismic Profiling (VSP) and surface seismic data were acquired simultaneously in three boreholes (BH1B, GH2,RL1) under pressure from gas. A weight drop was used as the source with 24 single components geophones, 2 m apart on the surface and 24 hydrophones, 1m apart, at 3 different depths in the boreholes. The acquired records were processed using Claritas software in order to obtain an image of the geologicalstructure in the vicinity of the boreholes. Surface and VSP data were separated from each other and different processing flows were adopted for each data set. The seismic images obtained from two of the surface profiles and the VSP profiles are providing information for the top 10m – 20m below the surface. The seismic sections are in agreement with thelocal geology and correlate very well with the borehole logs. The surface data from profile BH1B indicate a planar or nearly planar interface at depth 25m with velocity above the interface at 2200 m/s while the RL1 profile suggests a planar interface at 11m depth with formation velocity above at 2000 m/s. The seismic image for the VSP profile BH1B indicates an interface at 24m depth. The velocity for the formation above the interface ranges from 1600 m/s to 1900 m/s. Furthermore, the VSP profile RL1 identifies the water level at 18m from the surface and below a formation with velocity 4000 m/s.
Place, publisher, year, edition, pages
2013. , 66 p.
Examensarbete vid Institutionen för geovetenskaper, ISSN 1650-6553 ; 268
near surface, reflection, seismic, VSP, Ekeby, Östergötland
IdentifiersURN: urn:nbn:se:uu:diva-210539OAI: oai:DiVA.org:uu-210539DiVA: diva2:663058
Gripen Oil & Gas
Subject / course
Master Programme in Physics
Juhlin, Christopher, Professor