Wellbore seismic and core sample measurement analysis: integrated geophysical study of the Lake Bosumtwi impact structure, Ghana

• Author / Creator

  Meillieux, Damien Yves Justin

• Wellbore seismic measurements were recorded in the Lake Bosumtwi impact structure, Ghana, in 2004. A full range of petrophysical measurements were also performed in the laboratory on core samples from the same boreholes.
  The Vertical Seismic Profile shows low velocities for both P and S waves in the hardrock basement of the crater. Although we were expected to locate fractures within the rock, no upgoing waves were detected. Density and porosity measurements on the core samples indicate higher than normal porosity in the impact damaged rocks. Mercury porosimetry and SEM analysis characterized the pores as impact induced microcracks. These microcracks are most likely the reason for the low velocities observed on the seismic profiles, the in situ sonic logs, and the seismic velocity measurements on the core samples. Furthermore our laboratory P and S velocities measurements indicate a strong heterogeneity within the impactites.

• Subjects / Keywords

  • Microcracks
  • Rock damage
  • Bosumtwi
  • Impact crater
  • Porosity
  • Rock physics
  • Vertical seismic profile
  • Impactites

• Graduation date

  Fall 2009

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R38G9K

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.