Patent ID: 8191416

Claim:
A method for evaluating an underground formation penetrated by a wellbore, comprising: conveying an elongated tool having a longitudinal axis into the wellbore, the elongated tool having a transmitter coil and a receiver coil, at least one of the transmitter coil and the receiver coil having an axis tilted with respect to the longitudinal axis of the tool; injecting a fluid through at least a portion of the wellbore wall and into a portion of the underground formation; emitting an electro-magnetic wave into the underground formation using the transmitter coil; and measuring a resistivity value of the underground formation using the receiver coil, the resistivity value being indicative of a depth of invasion of the underground formation by the injected fluid, in a direction related to a tilting direction of at least one of the transmitter coil axis and the receiver coil axis.