Kriging

Kriging is a geostatistical interpolation method that estimates values at unknown locations on a variogram weighted average of the nearby data values. This compute task can be parameterized to perform simple or ordinary kriging.

Parameters

• source (object)
  • object (geoscience object reference)
    • Reference to a geoscience object containing the spatial locations of known values. Must be a pointset, downhole-intervals, regular-3d-grid, regular-masked-3d-grid, or tensor-3d-grid with schema version 1.2.0 or 1.3.0; or a block-model with schema version 1.0.0.
  • attribute (geoscience object attribute reference)
    • Reference to a one-dimensional continuous attribute inside source_object that contains the known values to be interpolated.

  • {
      "object": "https://{hub}.api.seequent.com/geoscience-object/orgs/{org_id}/workspaces/{workspace_id}/objects/path/my-pointset.json",
      "attribute": "locations.attributes[?name=='my-attribute']",
    }

• target (object)
  • object (geoscience object reference)
    • Reference to the geoscience object where kriging results will be stored. A new attribute containing the interpolated values will be created on this object. Must be a pointset, downhole-intervals, regular-3d-grid, regular-masked-3d-grid, tensor-3d-grid with schema version 1.2.0 or 1.3.0; or a block-model with schema version 1.0.0.
  • attribute (geoscience object attribute target)
    • Reference that points to an attribute inside target_object where the kriging results will be saved.

  • {
      "object": "https://{hub}.api.seequent.com/geoscience-object/orgs/{org_id}/workspaces/{workspace_id}/objects/path/my-pointset.json",
      "attribute": {
          "operation": "create",
          "name": "my-kriging-result"
      },
    }

• kriging_method (object)
  • The kriging method to use for interpolation. There are two supported methods.
    • Simple kriging:

    • {
        "type": "simple",
        "mean": 5.2  // The constant mean value assumed across the domain
      }

    • Ordinary kriging:

    • {
        "type": "ordinary"  // Variable mean value estimated from the data
      }

• variogram (geoscience object reference)
  • Reference to a variogram geoscience object that describes the spatial covariance structure within the domain. Must use schema version 1.1.0.
• neighborhood (object)
  • Search parameters that determine which nearby points to use for each evaluation point during kriging interpolation.

  • {
      "ellipsoid": {
        "ellipsoid_ranges": {
          "major": 100.0,      // Major axis length of the search ellipsoid
          "semi_major": 75.0,  // Semi-major axis length
          "minor": 50.0        // Minor axis length
        },
        "rotation": {
          "dip_azimuth": 45.0, // First rotation about z-axis (0-360 degrees)
          "dip": 30.0,         // Second rotation about x-axis (0-180 degrees)
          "pitch": 0.0         // Third rotation about z-axis (0-360 degrees)
        }
      },
      "max_samples": 15        // Maximum number of nearby samples to use
    }

• block_discretization (object, optional)
  • Sub-block discretization for block kriging. When provided, each target block is subdivided into x × y × z sub-cells and the kriged value is averaged across these sub-cells. When omitted, point kriging is performed at the block centroids.
  • Note: This parameter is only applicable when the target is a 3D grid (regular-3d-grid, regular-masked-3d-grid, tensor-3d-grid) or block-model. An error will be raised if used with pointset or downhole-intervals targets.

  • {
      "nx": 2,  // Number of sub-cells in the x-direction (1-9)
      "ny": 2,  // Number of sub-cells in the y-direction (1-9)
      "nz": 2   // Number of sub-cells in the z-direction (1-9)
    }

Example

For more information, see the kriging API reference.

Request

requests.post(
    "https://{hub}.api.seequent.com/compute/orgs/{org_id}/geostatistics/kriging",
    headers={"Authorization": "Bearer {token}"},
    json={
        "source": {
          "object": "https://{hub}.api.seequent.com/geoscience-object/orgs/{org_id}/workspaces/{workspace_id}/objects/path/my-pointset.json",
          "attribute": "locations.attributes[?name=='my-attribute']",
        },
        "target": {
          "object": "https://{hub}.api.seequent.com/geoscience-object/orgs/{org_id}/workspaces/{workspace_id}/objects/path/my-pointset.json",
          "attribute": {
              "operation": "create",
              "name": "my-kriging-result"
          },
        },
        "kriging_method": {
            "type": "simple",
            "mean": 10.5
        },
        "variogram": "https://{hub}.api.seequent.com/geoscience-object/orgs/{org_id}/workspaces/{workspace_id}/objects/path/my-variogram.json",
        "neighborhood": {
            "ellipsoid": {
                "ellipsoid_ranges": {
                    "major": 100.0,
                    "semi_major": 50.0,
                    "minor": 20.0
                },
                "rotation": {
                    "dip_azimuth": 45.0,
                    "dip": 30.0,
                    "pitch": 10.0
                }
            },
            "max_samples": 50,
            "min_samples": 10,
            "max_empty_octants": 0,
        },
    },
)

Result

{
    "message": "Kriging completed.",
    "target": {
       "reference": "https://api.{hub}.evo.seequent.dev/geoscience-object/orgs/{org_id}/workspaces/{workspace_id}/objects/path/my-pointset.json"
       "name": "My Pointset",
       "description": "A new description for my pointset.",
       "schema_id": "/objects/pointset/1.3.0",
       "attribute": {
         "reference": "locations.attributes[?key=='3cc3aa58-c928-4e79-b8ca-550174bff59e']",
         "name": "my-kriging-result"
      }
    }
}

Block Kriging Example

When the target is a 3D grid or block model, you can use block_discretization to perform block kriging instead of point kriging:

requests.post(
    "https://{hub}.api.seequent.com/compute/orgs/{org_id}/geostatistics/kriging",
    headers={"Authorization": "Bearer {token}"},
    json={
        "source": {
          "object": "https://{hub}.api.seequent.com/geoscience-object/orgs/{org_id}/workspaces/{workspace_id}/objects/path/my-pointset.json",
          "attribute": "locations.attributes[?name=='my-attribute']",
        },
        "target": {
          "object": "https://{hub}.api.seequent.com/geoscience-object/orgs/{org_id}/workspaces/{workspace_id}/objects/path/my-grid.json",
          "attribute": {
              "operation": "create",
              "name": "my-block-kriging-result"
          },
        },
        "kriging_method": {
            "type": "ordinary"
        },
        "variogram": "https://{hub}.api.seequent.com/geoscience-object/orgs/{org_id}/workspaces/{workspace_id}/objects/path/my-variogram.json",
        "neighborhood": {
            "ellipsoid": {
                "ellipsoid_ranges": {
                    "major": 100.0,
                    "semi_major": 50.0,
                    "minor": 20.0
                },
                "rotation": {
                    "dip_azimuth": 45.0,
                    "dip": 30.0,
                    "pitch": 10.0
                }
            },
            "max_samples": 50,
            "min_samples": 10,
        },
        "block_discretization": {
            "nx": 3,
            "ny": 3,
            "nz": 2
        },
    },
)