An Interactive 5-Day Training Course
Gross Rock Volume & Volumetric Mapping
Mapping Gross Rock Volume for Volumetrics
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Duration
5 Days
Price
$ 3,500
Starting From
01 Nov 2027
Home Geology and Geoscience Gross Rock Volume & Volumetric Mapping
Gross Rock Volume & Volumetric Mapping
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Gross Rock Volume & Volumetric Mapping - GG-GRV-PEA27
| Code | Date | Time | Duration | Location | Currency | Early Bird Fee Per Person |
|---|---|---|---|---|---|---|
| GG-GRV-PEA27 | 01 - 05 Nov 2027 | 10 AM CST | 4 Hours Per Day |
Online |
USD |
3500 |
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Gross Rock Volume & Volumetric Mapping
This training covers gross rock volume and volumetric mapping. It works through gross rock volume definition and its components, area depth curves, volume calculation methods, contact and spill point treatment, segment and compartment volumes, geometric and trap shape factors, structural uncertainty and its volume effect, net volume calculation, reconciliation between methods and the delivery of volumetric estimates.
Description
Gross rock volume is the largest term in a volumetric calculation and carries most of its uncertainty, particularly before a field is drilled. It is determined by the structure map, the contact depth and the spill point, and small changes in any of those can change the volume substantially, especially in low relief structures. Calculating it properly, and understanding how sensitive it is to each input, is a central skill in exploration and appraisal.
This training covers the subject in detail. Gross rock volume definition and its components are established first. Area depth curves follow, covering their construction and their use as the central tool for volume work. Volume calculation methods are then developed, covering integration, trapezoidal and pyramidal methods and grid based calculation. Contact and spill point treatment follows. Segment and compartment volumes are then addressed. Geometric and trap shape factors follow, covering their derivation and legitimate use. Structural uncertainty and its volume effect are then developed. Net volume calculation follows. Reconciliation between methods is addressed. The training closes with delivery.
The area depth curve is the tool that does most of the work. Measuring the area enclosed by each depth contour, and tabulating area against depth, gives a curve from which the gross rock volume for any contact depth follows by integration. Once the curve exists, the volume for every contact scenario is available immediately, the sensitivity to contact depth is visible as the slope of the curve, and the spill point appears as a change in the curve's character. Building the curve takes an hour and answers most volumetric questions.
Low relief structures are disproportionately sensitive and the effect is asymmetric. In a structure with twenty metres of relief, moving the contact ten metres changes the area within closure by a large fraction, so the volume changes by much more than ten per cent. Depth conversion uncertainty of that magnitude is routine. The effect is also asymmetric: a deeper contact adds area quickly on a flat flank while a shallower one removes it, so the volume distribution is skewed and the mean exceeds the most likely value.
Geometric factors are a shortcut with a specific validity. The volume of a trap can be approximated as the area at the contact times the height times a shape factor, with the factor depending on whether the structure is closer to a cylinder, a cone or something between. This is useful for screening and for checking a detailed calculation, and it is only as good as the shape assumption. Deriving the factor from the area depth curve of the actual structure, rather than using a default, makes it a reasonable approximation.
Finally, the volume should be calculated twice by different methods and reconciled. A grid based calculation from the structure, net to gross and porosity grids, and a calculation from the area depth curve with average properties, should agree closely. Where they do not, one contains an error: a unit conversion, a net to gross applied twice, a contact at the wrong depth or a grid extending beyond the closure. Reconciling them finds these, and it is the only reliable check on a volume that will reach a decision.
By the end of this training, participants will be able to:
- Define gross rock volume and its components
- Construct and use area depth curves
- Calculate volume by integration, trapezoidal and pyramidal methods
- Calculate volume from grids and reconcile against curve based methods
- Treat contacts and spill points correctly in volume calculation
- Calculate segment and compartment volumes and aggregate them
- Derive and apply geometric and trap shape factors
- Quantify the volume effect of structural and depth uncertainty
- Calculate net rock and hydrocarbon pore volume
- Deliver volumetric estimates with their sensitivities
The training is volume calculation practice on real structures. Participants build area depth curves and calculate volumes by several methods, reconcile the results and trace discrepancies. The volume sensitivity to contact depth and to depth conversion uncertainty is quantified for structures of differing relief. Deliberately flawed volume calculations are supplied for diagnosis.
Organisations sending participants to this training will:
- Calculate gross rock volume reliably
- Use area depth curves for contact sensitivity
- Reconcile volumes by independent methods
- Quantify the volume effect of structural uncertainty
- Recognise the sensitivity of low relief structures
- Reduce volume errors reaching decisions
Participants will:
- Build and use area depth curves
- Calculate volume by several methods
- Treat contacts and spill points correctly
- Quantify structural uncertainty effects
- Reconcile volume calculations
- Deliver defensible volume estimates
- Exploration geoscientists producing volume estimates
- Development geologists calculating in-place volumes
- Reservoir engineers using volumetric inputs
- Reservoir modellers producing model volumes
- Planning and reserves staff
- Graduate geoscientists learning volumetrics
- Technical staff reviewing volume calculations
Module 1 - Gross Rock Volume Components
- Gross rock volume definition
- Area and thickness components
- Structural closure and its definition
- Contact depth and its role
- Spill point and its effect
- Reservoir top and base surfaces
- Reservoir interval against gross rock volume
- Stratigraphic and structural trap differences
- Units and conversion factors
- Common definitional errors
- Relationship to in-place volume
- What dominates the uncertainty
Module 2 - Area Depth Curves
- Area measurement by contour
- Planimetry and digital area measurement
- Area depth tabulation
- Curve construction and plotting
- Reading the curve
- Slope and contact sensitivity
- Spill point expression on the curve
- Volume by integration of the curve
- Curves for multiple segments
- Curves above and below a contact
- Curve based scenario testing
- Documenting the curve and its source
Module 3 - Volume Calculation Methods
- Trapezoidal rule application
- Pyramidal rule and when it applies
- Switching between rules
- Simpson's rule
- Top slice and residual volume
- Grid based volume calculation
- Cell volume summation
- Grid resolution effects on volume
- Thickness limited against contact limited volume
- Combined structural and stratigraphic limits
- Volume above and below a surface
- Method comparison on one structure
Module 4 - Contacts and Spill
- Contact types and definitions
- Free water level against oil water contact
- Contact determination evidence
- Contact uncertainty and its range
- Contacts varying between segments
- Spill point identification on maps
- Spill point from the area depth curve
- Fill to spill assumptions
- Underfilled traps
- Column height limited by seal capacity
- Multiple spill points
- Contact scenarios and their volumes
Module 5 - Segments and Aggregation
- Segment and compartment definition
- Fault bounded segment volumes
- Stratigraphic compartment volumes
- Separate contacts per segment
- Segment by segment calculation
- Aggregating segment volumes
- Arithmetic against probabilistic aggregation
- Dependence between segments
- Shared contact assumptions
- Common risk across segments
- Reporting segment and total volumes
- Avoiding double counting
Module 6 - Geometric and Shape Factors
- Geometric factor concept
- Area times height times factor
- Factor values for standard shapes
- Cylindrical, conical and intermediate traps
- Deriving factors from area depth curves
- Factors by trap type
- Screening use of factors
- Checking detailed calculations with factors
- Limitations of the approach
- Factors in probabilistic calculations
- Area and height dependency
- Documenting factor derivation
Module 7 - Structural Uncertainty Effects
- Depth conversion uncertainty
- Structural interpretation uncertainty
- Multiple depth realisations
- Volume from each realisation
- Volume distribution from structural uncertainty
- Low relief structure sensitivity
- Asymmetry in the volume distribution
- Probability of closure failure
- Spill point uncertainty
- Combined structural and contact uncertainty
- Dominance over property uncertainty
- Reporting structural volume uncertainty
Module 8 - Net Volume, Reconciliation and Delivery
- Net rock volume calculation
- Net to gross application
- Pore volume calculation
- Hydrocarbon pore volume calculation
- Formation volume factor application
- Avoiding double application of factors
- Reconciling grid and curve methods
- Acceptable discrepancy levels
- Diagnosing volume discrepancies
- Volume deliverable content
- Sensitivity presentation
- Documenting the volumetric basis
Upon successful completion of this training course, delegates will be awarded an official Certificate of Completion issued by the Petroleum Engineers Association (PEA), an ISO 9001:2015 certified training organization. The certificate carries 10 Credits and formally records the total learning hours completed.
Each certificate is signed by the Course Facilitator and the CEO of the Petroleum Engineers Association, and serves as verifiable proof of professional training that delegates can present to employers and professional bodies worldwide.
Frequently Asked Questions
All course bookings made through PEA are strictly non-refundable. By registering for a course, you acknowledge and accept that all fees are payable in full and are not subject to refund under any circumstances, including changes in personal or professional commitments or partial attendance.
PEA reserves the right to make reasonable adjustments to course content, trainers, or schedules where necessary, without entitling delegates to a refund. Comprehensive details of each course — including objectives, target audience, and content — are clearly outlined before enrolment, and it is the responsibility of the delegate to ensure the course's suitability prior to booking.
For any inquiries related to cancellations or bookings, please contact our support team, who will be happy to assist you.
