ISCWSA validation of uncertainty and anti-collision calculations in Oliasoft WellDesign's Trajectory Design module
The ISCWSA provides comprehensive datasets and spreadsheets for validating software calculations. These resources ensure that software implementations adhere to recommended methods for calculating uncertainties and anti-collision models.
This validation involves testing our software against ISCWSA's published example datasets. Oliasoft WellDesign has recreated all scenarios presented by ISCWSA to validate our uncertainty and anti-collision calculations in the Oliasoft Trajectory module.
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Key Components of ISCWSA Validation
Example datasets include:
- Case #1: Three individual wellbores with NEV cov/uncertainties results for validating ISCWSA Uncertainty Models.
- Case #2: A field with a reference well and eleven offset wellbores all provided with EOU, center-to-center distance, and clearance/separation factor results for validating Anti-collision calculations.
Uncertainty and Anti-Collision Calculations:
- The datasets contain detailed trajectory inputs such as wellbore parameters, geomagnetic models, and survey error models - and verified results.
- Calculations are based on the latest revision of ISCWSA models and methodologies presented by Williamson.
Case #1 - Validating ISCWSA Uncertainty Models
- Plots of total COV element results from ISCWSA compared to Oliasoft WellDesign results.
- Oliasoft results are plotted as solid grey lines, while ISCWSA results as dotted lines.
![](https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/COv-1.jpg?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=750&s=80f363a45ba6469ad6ef47acd4857735 750w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/COv-1.jpg?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=1000&s=8722d9b89a76d99644e1882229946b58 1000w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/COv-1.jpg?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=1250&s=45c4121ef6bf984acdeec96bcccb6b54 1250w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/COv-1.jpg?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=1500&s=e9f76cfe129d8bdaa5433cf829442ade 1500w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/COv-1.jpg?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=1750&s=e6d67dc35667084a7fa5ddd88295c029 1750w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/COv-1.jpg?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=2000&s=0e8698ff5ab755a756d25fe3f9557c78 2000w)
Image 2: Calculated Covariance Matrix Elements from Oliasoft WellDesign and ISCWSA datasets, #1
![](https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Cov-2.jpg?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=750&s=6694fbffa236941d713537c532f8805a 750w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Cov-2.jpg?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=1000&s=6bf1285e991c6664daba8640df24a57c 1000w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Cov-2.jpg?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=1250&s=d36f7ef1f64a7383ed30f2bb4c41690f 1250w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Cov-2.jpg?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=1500&s=5411b8b4bcd8327032653ba4da06265b 1500w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Cov-2.jpg?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=1750&s=03f33bf55a1e28a5fa1967accd6042cd 1750w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Cov-2.jpg?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=2000&s=ceed41803648c287b2b10eca593fc2b1 2000w)
Image 3: Calculated Covariance Matrix Elements from Oliasoft WellDesign and ISCWSA datasets, #2
![](https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Cov-3.jpg?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=750&s=deddfce13307a4133cb2142a5a180a85 750w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Cov-3.jpg?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=1000&s=5169faf5d05e899c80d3f47691ad3e72 1000w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Cov-3.jpg?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=1250&s=21811ee175a6aa323834b872f544c2ad 1250w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Cov-3.jpg?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=1500&s=41216d4111002d076a4a725100a61320 1500w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Cov-3.jpg?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=1750&s=d57649a66565b413442222c63eddc9a7 1750w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Cov-3.jpg?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=2000&s=e8a6a9a5884b6ae4848227050fd3641f 2000w)
Image 4: Calculated Covariance Matrix Elements from Oliasoft WellDesign and ISCWSA datasets, #3
Case #2 - Validating Anti-Collision Calculations
Comparison of verified ISCWSA results against Oliasoft WellDesign calculations.
Focus areas include validation of:
- Ellipse of uncertainty (EOU) major axis
- Center-to-center distance
- Clearance/separation factor calculations.
The below results show a comparison of the verified results presented from ISCWSA against the calculated results produced in Oliasoft WellDesign. The presented validation follows the same format with Oliasoft results plotted as solid grey lines against dotted lines from ISCWSA.
The comparison will be presented to compare:
![](https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Image-5.jpg?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=750&s=d1d841593ef728b9de99452948c5ebc3 750w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Image-5.jpg?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=1000&s=2e547fadc5125fca664548fc4e00d25b 1000w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Image-5.jpg?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=1250&s=7686d28dbeed99fe289f6ad7157a427a 1250w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Image-5.jpg?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=1500&s=8127e773b743b038d35e477c334e6353 1500w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Image-5.jpg?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=1750&s=5bef22edc867d08b0c236216525cbd47 1750w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Image-5.jpg?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=2000&s=33cae128df86075e5041651bbf350e96 2000w)
Image 5: Wellbores from case #2 plotted in Oliasoft WellDesign’s 3D viewer
1. Uncertainty major axis:
![](https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Calculated-EOU-major-axis-from-Oliasoft-WellDesign-and-ISCWSA-dataset-2.png?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=750&s=292ef7ab25ea3a98fc19cde35304a156 750w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Calculated-EOU-major-axis-from-Oliasoft-WellDesign-and-ISCWSA-dataset-2.png?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=1000&s=7bdf0a5e3ad8da5bf7331f51800d5332 1000w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Calculated-EOU-major-axis-from-Oliasoft-WellDesign-and-ISCWSA-dataset-2.png?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=1250&s=3f3686ebe43d3c9cad46ec3fb3f9f512 1250w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Calculated-EOU-major-axis-from-Oliasoft-WellDesign-and-ISCWSA-dataset-2.png?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=1500&s=15ff6441352a2d7f378d541dde22e241 1500w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Calculated-EOU-major-axis-from-Oliasoft-WellDesign-and-ISCWSA-dataset-2.png?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=1750&s=7713a58c7c9b606fa13c5fb52b339530 1750w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Calculated-EOU-major-axis-from-Oliasoft-WellDesign-and-ISCWSA-dataset-2.png?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=2000&s=1076f50bcf301f0f318490ba48678171 2000w)
Image 6: Calculated EOU major axis from Oliasoft WellDesign and ISCWSA dataset #2
![](https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Screenshot-2024-07-08-at-16.00.19.png?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=750&s=a51bbb237349b458f6b36271322c86a8 750w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Screenshot-2024-07-08-at-16.00.19.png?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=1000&s=3cb718cffb816ae718dd22b99b240100 1000w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Screenshot-2024-07-08-at-16.00.19.png?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=1250&s=076b136b20c043fa337ec76cfb857bdc 1250w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Screenshot-2024-07-08-at-16.00.19.png?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=1500&s=8566015a7a218565b1e425e9ef2936c3 1500w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Screenshot-2024-07-08-at-16.00.19.png?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=1750&s=4199bff61b9ea2f2ac7c65b22ce80925 1750w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Screenshot-2024-07-08-at-16.00.19.png?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=2000&s=e12cb96ff028c1a6be426cd7cd51a119 2000w)
Image 7: Calculated EOU major axis from Oliasoft WellDesign and ISCWSA dataset #2
2. Center-to-center distance calculation:
![](https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Calculated-center-to-center-distance-from-OWD-and-ISCWSA.png?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=750&s=5a42efd13dfcecc39295ec7b9d02319d 750w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Calculated-center-to-center-distance-from-OWD-and-ISCWSA.png?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=1000&s=7e18084cd94e9b4a7ab8d2bcdda6c28c 1000w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Calculated-center-to-center-distance-from-OWD-and-ISCWSA.png?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=1250&s=4935f83b5517893100029c4f808f5a8a 1250w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Calculated-center-to-center-distance-from-OWD-and-ISCWSA.png?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=1500&s=7a8e9e42c8707e909a644c20f7a3cc9e 1500w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Calculated-center-to-center-distance-from-OWD-and-ISCWSA.png?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=1750&s=00969dbe492f9e1611eca1beb636c385 1750w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Calculated-center-to-center-distance-from-OWD-and-ISCWSA.png?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=2000&s=fc46e25452fe0e75241e1f063599015d 2000w)
Image 8: Calculated center-to-center distance from OWD and ISCWSA
![](https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Center-to-Center-distance-between-reference-well-and-offset-wells.png?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=750&s=d878f649a5b78842f3a380e658158ece 750w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Center-to-Center-distance-between-reference-well-and-offset-wells.png?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=1000&s=80f6b557383aa4fdd883cd0941ea4b0b 1000w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Center-to-Center-distance-between-reference-well-and-offset-wells.png?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=1250&s=c4116b6b8cfb06273418738fcb57e60a 1250w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Center-to-Center-distance-between-reference-well-and-offset-wells.png?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=1500&s=5df609c65dac3c0a89f4dee370123db0 1500w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Center-to-Center-distance-between-reference-well-and-offset-wells.png?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=1750&s=6b30aa4bcf79c8c2281f873f9fc7373f 1750w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Center-to-Center-distance-between-reference-well-and-offset-wells.png?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=2000&s=bc27005413a4a888341ac3e4fbbeccdc 2000w)
Image 9: Calculated center to center distance from Oliasoft WellDesign and ISCWSA
3. Clearance/Separation factor calculation:
![](https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Separation-Factor-between-reference-well-and-offset-wells.png?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=750&s=b3d456347ad43f4575d0c1758fd1e4c6 750w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Separation-Factor-between-reference-well-and-offset-wells.png?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=1000&s=0400e288e06b2f7d0dd7275cec2094ee 1000w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Separation-Factor-between-reference-well-and-offset-wells.png?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=1250&s=a412a1b6e10779e7d8444faeea808fcc 1250w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Separation-Factor-between-reference-well-and-offset-wells.png?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=1500&s=49a13b8319580e393c06985ace4f344b 1500w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Separation-Factor-between-reference-well-and-offset-wells.png?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=1750&s=86ad5f3a2b2086e2f2a8f20e5c60a861 1750w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/Separation-Factor-between-reference-well-and-offset-wells.png?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=2000&s=a2730280656117112dfb16c5b53c2251 2000w)
Image 10: Calculated clearance/separation factors from Oliasoft WellDesign and ISCWSA
![](https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/clearanceseparation-factors-2.png?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=750&s=5612893d8b8f579de9cb6a44533d7e0f 750w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/clearanceseparation-factors-2.png?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=1000&s=a4db1107eedcacc14868dece85cc3754 1000w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/clearanceseparation-factors-2.png?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=1250&s=5e300660185a326b4d5fa7a4a016ea5b 1250w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/clearanceseparation-factors-2.png?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=1500&s=bf04219f89b24d5a631ad799ccd1a54b 1500w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/clearanceseparation-factors-2.png?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=1750&s=910d1e26d9d00fef8db3183e439c0bee 1750w, https://oliasoft.imgix.net/images/Articles/ISCWSA-validation/clearanceseparation-factors-2.png?auto=compress%2Cformat&cs=srgb&fit=clip&q=75&w=2000&s=f101fea901b84da466facdc8652e0385 2000w)
Image 11: Calculated clearance/separation factors from Oliasoft WellDesign and ISCWSA
Implications for the Industry
By validating Oliasoft WellDesign against ISCWSA standards, we demonstrate our commitment to accuracy and reliability in wellbore surveying. This rigorous validation process ensures that our software meets industry standards, providing our clients with confidence in their wellbore modeling and surveying results. Our alignment with ISCWSA standards underscores our dedication to maintaining industry best practices and fostering a collaborative understanding of wellbore surveying challenges.
For detailed information on the ISCWSA validation process and access to the example datasets, please visit the following links:
- ISCWSA Clearance Test Word Document
- ISCWSA Clearance Test Excel Sheet
- ISCWSA Error Model Example File 1
- ISCWSA Error Model Example File 2
- ISCWSA Error Model Example File 3
By continually validating and refining our software, Oliasoft WellDesign remains at the forefront of wellbore surveying technology, ensuring precision and safety in all drilling operations.