Construction and Interpretation of Structural Map Using Seismic Reflection Times in Location of Prospective Hydrocarbon Trap

Geophysical investigation of the subsurface structure at Mapi, Niger Delta area was carried out by the construction and interpretation of structural maps using Seis mic reflection t imes. Surfer 8.0 software was used for the structural interpretation to prepare the contour map fro m seis mic reflection times, with a view to identify surface location of prospective geologic traps containing hydrocarbon. The acquired seismic reflection time data fro m Mapi field was computed into the surfer 8 software and the structural map was generated, showing all the contours. The map showed that the geological formation mapped is upfolded, downfolded, d ipped gently and tipped steeply in different areas. This indicates that the topography of the sedimentary bed is not of a particular type. Two anticlines were seen in two areas of the map (high contour closed) labeled A and B in red. These anticline structures are prospective traps to be test drilled. The study showed that anticline B is more p ros pective than anticline A because B is larger in size and deeper than A. The surface location of tops of the anticline A and B are indicated by red dots, the position coordinates are respectively A (424272, 205337) and B (427257, 203995). Also the study revealed a steeply dipping potion of the sedimentary bed shown by closely spaced group of contours decreasing toward the northern part of the map, this is also a target. This steeply dipping feature suggests an indication of position of tilted and faulted part of the format ion. To min imize drilling risk, exp loratory well could be located on anticline B first, to test the predicted stratigraphy of oil and gas accumulation.