5. Exploration Geophysics

Survey Design — Quiz

Test your understanding of survey design with 5 practice questions.

Practice Questions

Question 1

A seismic reflection survey is designed to image a deep geological structure at $5 \text{ km}$ depth. If the average P-wave velocity in the overlying rock is $3000 \text{ m/s}$, and the desired vertical resolution is $10 \text{ m}$, what is the approximate minimum frequency required for the seismic source to achieve this resolution, assuming a quarter-wavelength criterion for resolution?

Question 2

When designing a controlled-source electromagnetic (CSEM) survey for hydrocarbon exploration in a marine environment, which of the following factors is most critical in determining the optimal source-receiver offset and frequency range to maximize sensitivity to resistive hydrocarbon reservoirs?

Question 3

A microgravity survey is planned to detect a small, shallow void (e.g., a cave or tunnel) with an expected density contrast of $-1500 \text{ kg/m}^3$ relative to the host rock. If the void is anticipated to be approximately $5 \text{ m}$ below the surface and have a diameter of $2 \text{ m}$, what is the most significant challenge in terms of noise mitigation for this survey?

Question 4

When planning a high-resolution ground penetrating radar (GPR) survey to map rebar within a concrete structure, which of the following resolution requirements is paramount for accurate structural assessment?

Question 5

A resistivity survey is being designed to delineate a contaminated groundwater plume. If the plume is characterized by a significantly lower resistivity than the surrounding aquifer, and is expected to be at a depth of $20 \text{ m}$, what is the most appropriate electrode array configuration to maximize sensitivity to this horizontal target at depth while minimizing the effects of near-surface heterogeneity?