The Petrophysics tab provides views and commands for calculating, interpreting, and editing well-log data.

This overview explains the ribbon layout and behavior shared by the calculation wizards. For calculation methods and required inputs, use the dedicated topics under Petrophysics in the contents.

Ribbon groups

The ribbon contains eight groups. Some button captions are shortened; point to a button to see its full command name.

• Views – use its button to open or return to the Petrophysics window, which contains the Well correlation view, Cross-plot view, and Well log histogram.
• Properties – Evaluation (Petrophysical Evaluation), Shale Volume, Porosity, Permeability, NMR T2 (NMR T2 interpretation), and Saturation.
• Core – Saturation Height Model.
• Lithology – Lithology (Lithology interpretation), Electrofacies, and Mineral Volume Estimation (ribbon caption Mineral volume).
• GeoMech – Base properties, Pore pressure, Elastic (Elastic properties), Horizontal stress, UCS, and Focal mech. (Focal Mechanism).
• Rock Physics – Fluid sub (Fluid substitution).
• Image logs – Dip detection.
• Logs – Edit curve (see LAS editing), Calculator (see Well log calculator), ML predict (ML Log prediction), and Env. corr. (Environmental Corrections).

Working with calculators

The calculation wizards are modeless: the ribbon, views, and Data manager remain available while a wizard is open. You can inspect results in the views between Run cycles without closing the wizard.

Controls vary by tool, but the shared controls behave as follows when present:

• Method – selecting a method leaves only the input curves and parameters used by that method visible.
• Input curves – each list contains the selected well's curves. A field is pre-filled when a curve has the required log type and remains empty when there is no match.
• Units – each curve and numeric parameter has its own unit list or label. Defaults follow the project measurement system: for example, density uses g/cc in Metric projects or lb/ft³ in Imperial projects, travel time uses µs/m or µs/ft, and proportional values use a fraction or %.
• Batch calculation – the list offers All wells plus saved well filters, well folders, and well sections, so one run can be limited to a project group.
• Input/Output – the preview title includes the selected well and displays its inputs with the calculated output. When the panel is widened, its curve tracks remain equal in width and grow proportionally.
• Panel size – drag the divider to give the inputs or the preview more room; neither side can be hidden completely. Each wizard remembers its size, including after g-Space restarts. Log calculator has no such divider.
• Run report – after a run, the wizard lists completed wells separately from wells skipped because a required input curve was missing. No empty output curve is created for a skipped well.

Depth and zones

• Depth ranges – MD range, TVD range, TVDSS range, and Markers range express the same Start and End boundaries in different depth references. Enabling a boundary on one tab enables it on every tab, and its unit follows the project measurement system. Scrolling the mouse wheel over a numeric depth-range field leaves its value unchanged; enter a value or use its arrow buttons to change it.
• Full depth – a cleared boundary remains disabled and shows the shallowest or deepest point of the selected well on the numeric tabs; the marker lists remain Undefined. Selecting another well refreshes these values. In a batch run, each well uses its own available interval, and a well without trajectory data is skipped.
• Range validation – Base properties and Petrophysical Evaluation reject an enabled pair in which Start is not shallower than End and report Start depth must be shallower than End depth.
• Zones range – select one or more zones from the default marker dataset. Use Set default in the Data manager to use zones from another dataset. If none are available, the tab reports No zones are available for the default marker dataset "<marker dataset>". or No marker zones are available in the project.
• Interval area – the active depth or zone tab determines the initial height. Drag the horizontal border below the tabs to make a long marker or zone list larger and return space to the parameters below. The wizard remembers the height you set.

Calculated curves

A saved result carries the LAS mnemonic and log Type of the quantity it represents. The result is therefore recognized like an imported curve and can be pre-filled in a later calculation.

• Base properties writes temperature as TEMP with the type Temperature; Lithology interpretation writes LITH with the type Lithology.
• Elastic properties uses the mnemonic of the calculated property, for example VPVS with the type Vp/Vs Ratio.
• Mineral Volume Estimation assigns Mineral Volume to every mineral component, including user-defined minerals.
• Petrophysical Evaluation assigns quantity types such as Permeability and Bulk Water Volume, uses Petrophysics QC for clip, net-reservoir, and net-pay flags, and uses Mineral Model QC for mineral-model diagnostics.

When a project is opened, a calculated curve saved by an earlier version receives a missing type automatically. A type selected manually is preserved.

Workflow tasks

Many petrophysical wizards can be added to the project Workflow and run again as tasks. When a wizard provides the shared action row, its buttons are:

• Save to workflow – stores the selected wells, input and output curves, method, parameters, user-defined constants, and output names as a task.
• Run – executes the calculation with the current settings. This replaces the former Calculate button.
• Save – stores the calculated result in the well.
• Close – closes the wizard.

Reopening a task restores its saved settings so they can be reviewed, edited, run, and saved back to the task.

Saved zone selections are checked against the current project. Zones whose marker dataset was removed, or whose dataset is no longer the default, are removed from the restored setup. Wizards that report the change use the messages Some zones saved in this workflow are no longer available in the project and were removed from the calculation setup. and Some zones saved in this workflow belong to a marker dataset that is not the default one and were removed from the calculation setup. Set that dataset as default to use them. In Lithology interpretation, the wording is interpretation setup; Permeability and Elastic properties remove unavailable zones without a message.

Replacing output curves

When a wizard uses the shared overwrite check, saving a result whose output name already exists opens a Confirm message before anything is written. For one well it says The well "<well name>" already contains a curve with that name. Do you want to overwrite it? For several wells it says Some wells already contain a curve with that name. Do you want to overwrite it?

Yes, which is preselected, replaces the existing curve in every affected well. No cancels the save and leaves the wizard open with the result unsaved. A curve in an uneditable LAS file cannot be replaced.

Mineral Volume Estimation handles existing curves with its own Curve overwrite setting.

The Well log calculator writes a calculated curve with either Run or Save. Its own confirmation names the curve and well and can be applied to all remaining wells. A Log calculator task run by a Workflow replaces an existing curve without confirmation.