Description

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🧲 Res2DInv 2026.2.1 & Res3DInv 2026.1 — Professional 2D / 3D Resistivity & IP Inversion Software

⚡ Res2DInv and Res3DInv are the worldwide standard for turning electrical resistivity tomography (ERT / DC) and induced polarisation (IP) field data into trustworthy 2D and 3D models of the subsurface. Born as Geotomo software from the inversion research of Dr M.H. Loke and now developed inside Seequent, the Bentley Subsurface Company, the 2026 line is built for geophysicists, hydrogeologists, environmental consultants, mining teams and geotechnical engineers who need models they can defend — in the field and in the office.

🌍 Use cases include groundwater and aquifer mapping, saltwater intrusion, contamination plumes, clay vs sand discrimination, void and bedrock mapping, mineral zoning, tailings and infrastructure monitoring, and time-lapse environmental surveillance. Import almost any commercial instrument format, clean resistivity and full-decay IP, invert with smooth / sharp / constrained methods, then push georeferenced results into Oasis montaj, Leapfrog, Aarhus Workbench, VTK and ParaView.

📦 Current versions in this listing: Res2DInv 2026.2.1 (feature release 2026.2 + critical import fix) and Res3DInv 2026.1 (compatibility and Seequent Connector stability). Both are 64-bit Windows desktop applications licensed with a Seequent ID via MySeequent.

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✨ Why teams standardise on Res2DInv / Res3DInv

• ✅ Fast, automatic inversion — no starting model required — with full expert control when you need it
• ✅ Virtually every electrode layout: Wenner, dipole-dipole, pole-pole, pole-dipole, Wenner-Schlumberger, gradient, custom, borehole, underwater, streamed and vector arrays
• ✅ Topography, water layers, fixed regions and time-lapse in one workflow
• ✅ In-field speed on a laptop; large-mesh 3D on a workstation with up to 256 GB RAM
• ✅ Native path into the Seequent ecosystem (Oasis montaj, Leapfrog, Workbench, Connector)

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🚀 What’s new in Res2DInv 2026.2 and 2026.2.1

🎯 2026.2 theme: get cleaner IP into the inversion, and get models out of Res2DInv into Oasis montaj and Leapfrog without fighting coordinates. 2026.2.1 is the current supported build: same features as 2026.2, plus a point-release fix for an import error that could stop inversion when using instrument importers or certain .dat layouts.

🗺️ Integration with Oasis montaj & Leapfrog

• 📤 Export georeferenced grids straight to Geosoft grid format
• 📐 Straight and crooked sections keep real-world alignment — no manual nudge after export
• 🔗 Spatial context survives the hop into Oasis montaj and Leapfrog so geology, drilling and resistivity sit on the same map

📉 Full-decay IP workflow (the 2026 headline feature)

Instead of treating IP as a single integrated number, Res2DInv 2026 lets you inspect and edit the entire decay curve before inversion. That is how you separate earth signal from coupling, late-time noise and bad gates.

• 👁️ View every IP window and the full decay for each measurement
• 🚫 Enable / disable a whole curve or selected gates across the dataset
• 🙈 Hide disabled points so profile and decay plots autoscale on the good data
• 🎨 Apply one colour scale across all IP windows and integrated IP
• ✂️ Separate slope and sign filters for full-decay IP
• 💾 Manual QC edits are preserved when you apply filters later
• 📋 Full-decay details appear in the dataset information tab
• 🔢 NaN values accepted on import

🧱 Model setup before you invert

• 📍 View fixed regions and edit resistivity + weight
• 💧 View water layers / surfaces and edit resistivity, IP and elevation
• ⚙️ Open inversion settings from an imported .r2r model
• 📁 Save those settings to an .ivs file and reuse them on the next line

🛠️ Everyday speed-ups

• ↩️ Undo the last processing step — including manual edits and filters — without starting over
• 🔀 “Merge .dat files” now works on a single file (ideal for reversing a profile)
• 📍 Original coordinates are preserved when merging files
• ⚡ Improved performance on large borehole datasets
• ⌨️ Electrode editor: paste a block of cells from Excel; Tab moves one cell right

🐛 Bugs fixed in Res2DInv 2026.2

• 🔧 Integrated IP now recalculates after an IP processing filter
• 🔧 Log colour scales no longer break on IP windows that contain negative values
• 🔧 Global coordinates kept when saving .dat files that include borehole info
• 🔧 Reversed profiles no longer mirror distance around the first electrode during merge
• 🔧 Inversion no longer fails on index-based formats with very small electrode spacing

🩹 What 2026.2.1 specifically fixes

• ✅ Import error during inversion when using instrument data importers or loading .dat files with particular formatting — resolved in 2026.2.1

📌 Seequent lists 2026.2.1 as the current Res2DInv version. Supported desktop line: 2026.2.1 back through 5.0.0.

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🔬 What’s new in Res2DInv 2026.1 (foundation of the 2026 IP tools)

2026.1 shipped the first full-decay IP tools. 2026.2/2026.2.1 build on them, so buyers of the current installer get both generations of work.

• 📈 Shifted IP decay curves on a log-scale profile — patterns and outliers jump out
• ⚠️ Negative IP values marked for instant QC
• 🔍 Dedicated Decay Plot to inspect and edit gates measurement by measurement
• 🧹 Slope filtering + auto-disable of negative gates
• 📝 Log entry when integral IP is discarded on import because a value sits outside the allowed range

2026.1 stability fixes: Autoscale colours no longer errors on Sensitivity / Uncertainty; Compare colours stay correct when Autoscale is toggled; automatic colour scales work when all IP values are identical or nearly flat; bulk Geosoft-grid export no longer fails when Display Type is “Both”; rectangular models no longer get a “_trapezoidal” filename suffix; legacy .inv files with a huge number of time-lapse steps load again.

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🧊 What’s new in Res3DInv 2026.1

🧭 Compatibility-first release. Res3DInv 2026.1 does not add a new inversion engine. It updates the 3D platform so large ERT/IP jobs stay stable and remain compatible with connected Seequent workflows — including the latest Seequent Connector.

That matters if you combine 2D lines into 3D, run time-lapse cubes, or hand models to Leapfrog / Workbench / montaj. You still get the full 3D product:

• 🧱 True 3D inversion and 3D inversion of combined 2D survey lines
• 🌊 Water bodies, water layers and streamed electrode arrays
• 📡 Vector-array datasets (e.g. IRIS Full Waver)
• ⏱️ 2D and 3D time-lapse (Professional / higher licence tiers)
• 🧮 Large meshes — on the order of ~10 million nodes with ~128 GB RAM; up to 256 GB RAM supported
• 📤 Export to Workbench, Oasis montaj, Leapfrog, VTK, ParaView and other 3D viewers

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🧭 What the software does every day (not just “what’s new”)

Res2DInv — 2D ERT & IP

• 📥 Import → filter → invert → visualise in one desktop workflow
• 📺 Live pseudosection updates while you work
• 🕳️ Process and invert borehole, cross-borehole and surface-borehole data
• ⏳ 2D time-lapse inversion and easy collation of repeat surveys
• 🎨 Compare models, sync colour scales, bulk invert / bulk display / bulk export
• 📄 Optional resistivity-only inversion when IP is too noisy to keep

Res3DInv — 2D + 3D ERT & IP

• 🧩 Everything in Res2DInv, plus full 3D inversion and 3D visualisation
• 📏 Surface, topography, borehole, water and streamed geometries
• 🧠 Smooth, sharp or constrained inversion with optional known-geology constraints
• 📦 Volume of Investigation (VOI) and high-RAM Professional options on eligible licences

Typical instruments & files

📥 Native and converted formats commonly include .dat, ABEM Terrameter databases, Iris Instruments, AGI SuperSting, Geosoft GDB, Instrumentation GDD, Zonge .dat, MAE, OYO and McOHM. Export inversion models as XYZ, Geosoft grids, VTK and other interpretation formats.

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💻 System requirements (official Seequent guidance)

Item	Minimum	Recommended
🖥️ Operating system	Windows 10, 64-bit	Windows 11, 64-bit
🧠 Processor	4 CPU cores	16 CPU cores
💾 System memory	4 GB RAM (typical 2D lines)	8 GB+ for Res2DInv; far more for big Res3DInv / time-lapse jobs
💽 Storage	10 GB free	256 GB fast SSD (Res3DInv buffers large meshes on disk)

💡 A modern laptop with 4 GB+ RAM will invert ordinary 2D lines in a few minutes. Extra cores help most when you jump from 4 to 16 CPUs; going from 18 to 32 gives a smaller extra gain. Res3DInv can address up to 256 GB RAM on Professional-class licences. Keep plenty of free SSD space — swap files should be several times RAM on heavy 3D jobs.

🔐 Licensing uses Seequent ID / Seequent Connector (not the old USB dongle workflow of legacy Geotomo builds). Download installers from MySeequent.

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💡 Interesting facts (useful for Google — and for buyers)

• 📚 Res2DInv is the commercial descendant of Loke & Barker’s smoothness-constrained least-squares 2D resistivity inversion — the method most ERT papers still treat as the reference implementation.
• 🏆 It became the de facto teaching and production standard in universities, water agencies and mineral explorers long before the Seequent acquisition of Aarhus GeoSoftware / Geotomo products.
• 💧 Case in point: Living Water International used Res2DInv resistivity sections to site wells instead of “drill and hope,” cutting dry holes in difficult aquifers.
• 🔋 The 2026 story is IP growing up: full-decay QC means chargeability models are no longer a black box built from a single integral that hid bad gates.
• 🧩 Res3DInv 2026.1 looking “quiet” on features is deliberate — Connector and licence-stack updates keep 3D projects opening after platform changes. Stability releases are the ones that save a week of rework on a 3D cube.
• 🏷️ Version tip for search and support tickets: ask for Res2DInv 2026.2.1 (not only “2026.2”) so you get the instrument-importer fix.

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🛒 Which product should you put in the cart?

• 🟩 Res2DInv only — 2D ERT/IP lines, groundwater, environmental and most geotechnical profiles; 2D time-lapse; in-field QC.
• 🟦 Res2DInv + Res3DInv bundle — true 3D volumes, stitching 2D lines into 3D, mining and infrastructure blocks, vector arrays, large meshes, 3D time-lapse, full 3D viewer.

Licence tiers historically include Starter / Basic / Professional limits on electrodes, RAM, mesh size and time-lapse. Confirm the exact SKU and seat type with your Seequent or Bentley reseller before checkout.

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⭐⭐⭐⭐⭐ — Production ERT/IP workhorse
Senior geophysicist, environmental & water projects

“Res2DInv 2026.2.1 is what we actually run after the survey, not a demo toy. Full-decay IP QC finally lets us kill bad gates before inversion, and georeferenced crooked-section export into Oasis montaj / Leapfrog saves a painful afternoon of shifting grids. Fast on a field laptop, honest about noisy data, and Res3DInv 2026.1 stays compatible with Seequent Connector when we stitch lines into 3D. Still the standard for resistivity and IP modelling.”