1. Important logging methods for the exploration of hydrocarbons include: Electric Logging: It measures the electrical resistivity of the formations penetrated by the borehole. The resistivity of rocks is directly related to their porosity and the nature of the fluids filling the pore spaces. Spontaneous Potential Logging: It measures the natural potential difference between the drilling mud and the formation fluids. This method is used to determine the type and nature of the formation fluids, as well as the shaliness of the formations. Sonic Logging: It measures the travel time of sound waves through the formation. This method is used to determine the porosity, density, and compaction of the formations. Density Logging: It measures the density of the formation using gamma rays. This method is used to determine the porosity and lithology of the formations. Caliper Logging: It measures the diameter of the borehole. This method is used to detect any washouts, caves, or ledges in the borehole, which could affect the interpretation of other logs