2. A resistivity survey was conducted to explore hydrocarbon potential in an area. The inverted resistivity section and resistivity of rock types within the area are shown in figure 1 and table 1 respectively. Sketch three (3) possible interpretations of the resistivity section. 25 marks Distance (m) 300 600 900 1200 1500 1800 2100 2400 2700 3000 3300 0 E 100 Depth (m) 200 300 RESISTIVITY (ohm-m) 700 Figure 1. Inverted resistivity section Resistivity (ohm.m) Rock type 1-180 Clay 150 - 500 Salford Shale 300 - 700 Oil barren Sandstone Oil saturated sandstone 600-900 750-1000 limestone Gabbro 800- 1400 1100-2300 Marble Table 1. Resistivity of some rock types Interpretation 1 Distance (m) 900 1200 1500 1800 2100 2400 2700 3000 3300 O 300 600 100- Depth (m) 200- 300 RESISTIVITY (ohm-m) 700 Interpretation 2 Distance (m) 1200 1500 1800 2100 2400 2700 3000 3300 300 600 900 100 Depth (m) 200- 300 RESISTIVITY (ohmm) 700 Interpretation 3 Distance (m) 800 900 1200 1500 1800 2100 2400 2700 3000 3300 300 100 Depth (m) 200- 300 RESISTIVITY (ohm-m) 700