Geologist interview questions

I've been a geologist for eight years, five in Oman. Started in operations geology with an Indian operator drilling exploration wells in the Krishna-Godavari basin, then moved into development geology, and for the past four years I've been at PDO covering both exploration and field development on conventional sandstone and complex carbonate plays. My current focus is the southern Oman tight carbonates; complex reservoirs that need careful integration of seismic, well data, and geological knowledge. I hold an MSc in petroleum geology.

Multi-element analysis. Trap: confirm structural closure (4-way, 3-way against a fault, stratigraphic), assess sealing capacity. Reservoir: estimate effective reservoir thickness and quality from analogs and direct evidence (any nearby wells). Source: confirm mature source-rock kitchen with migration path to the prospect. Migration timing: did the trap form before or after hydrocarbon migration. Each element has an associated probability; the prospect's chance of success is the product. I document all assumptions and uncertainties in a prospect evaluation report. Independent peer review by another geologist before recommending to management.

Start with the structural framework: depth conversion of seismic horizons, interpretation of faults, building a structurally consistent model in Petrel. Then layer the stratigraphy: define zones and sub-zones based on the wells and the depositional understanding. Facies modelling: distribute facies in 3D based on well control and depositional concept (object modelling for channels, sequential indicator simulation for more uniform settings). Petrophysical properties: porosity, permeability, saturation distributed within each facies. Multiple realisations to capture uncertainty. The model is a hypothesis to be tested against dynamic data, not a fact.

Quantify it explicitly. For structural depth: depth-conversion uncertainty propagated through to volume estimates. For reservoir quality: range from best-case (highest porosity wells) to worst-case (lowest) with the most-likely value. For trap integrity: probability of seal failure based on sealing capacity analysis. Output is a probabilistic range (P10/P50/P90), not a single value. Critical for decision-makers: a P50 case of 100 million barrels with P90 of 30 and P10 of 250 tells a much richer story than just '100 million barrels'. Single-value interpretations mislead executives into thinking we're more certain than we are.

We're partners. I provide the pre-drill geological prognosis: expected depths of formation tops, expected reservoir quality, key risks to watch for. The operations geologist provides real-time wellsite data while drilling: cuttings descriptions, gas readings, mud-logging data, casing-shoe pressures. We have a real-time data channel; I'm available 24/7 during critical sections of the well. When drilling encounters something unexpected I help interpret quickly so operations can make the right calls (continue, side-track, set casing). Good drilling outcomes depend on this collaboration.

For a senior geologist role with major operator experience in Oman I'd target OMR 2,200 to 2,700 total package depending on the bonus and asset scope. Roles with both exploration and development scope, or on flagship development assets, command a premium. I'm on 90 days' notice. Beyond pay I'd value the calibre of the technical work; my career is built on the studies I've led.