Daily report & productivity metrics
Learning objectives
- Build a daily bar chart: good VPs, weather-down, mechanical-down
- Read the cumulative S-curve: plan vs actual vs forecast
- Compute forecast completion date and schedule slip
- Link crew day rate to cost-of-slip in dollars
The daily report is the operations heartbeat of every survey. It captures what the crew did in the last 24 hours, what went wrong, and where the project is heading. The client, HQ, and the crew chief all read the same document every morning; disagreement about the numbers is where projects bleed money.
Daily bar chart
Each day’s VP budget splits three ways: good shots that entered the processing pipeline, weather-down VPs (scheduled but unable to fire due to wind, rain, lightning, swell), and mechanical-down VPs (vibrator breakdown, cable fault, bird-controller failure). The three stack up to the day’s nominal VP target. A bar short of target means downtime that will show up in the S-curve as a flat day.
Cumulative S-curve
Plotting cumulative VPs against time gives the survey’s signature S-curve. The plan is a straight line from 0 to target over the planned period. The actual is a stepped curve that tracks or falls behind the plan. Forecast completion is computed by extrapolating the recent average daily rate out to the target — if that line crosses day N+slip, the survey is slipping by slip days.
Cost of slip
Land crew day rate: typically 150k for a medium crew including trucks, people, office, and fuel. Marine streamer vessel: 700k/day. A 5-day schedule slip on a marine job is a $2–3M cost overrun. That single number motivates the entire QC chain: every hour of real-time QC, binning QC, signature QC, first-break QC, and navigation QC exists to avoid a schedule slip whose direct cost dwarfs the QC effort by orders of magnitude.
Reading patterns
Weather days cluster: a storm takes out a week in winter North Sea. Mechanical failures scatter: one or two per week on a well-maintained crew, four-plus signals a fleet aging out of spec. A flat S-curve for a week means investigate: either a weather pattern, a site-prep delay, or a recurring mechanical issue. The single most useful daily habit: read the bar chart first (what went wrong today?), then the S-curve (are we still on plan?), then the cost-to-date.
References
- Cordsen, A., Galbraith, M., Peirce, J. (2000). Planning Land 3-D Seismic Surveys. SEG Geophysical Developments 9.
- Stone, D. G. (1994). Designing Seismic Surveys in Two and Three Dimensions. SEG Geophysical References 5.
- Pritchett, W. C. (1990). Acquiring Better Seismic Data. Chapman & Hall.