Method for generating a three-dimensional digital model of a drill core and computer-readable storage media
The present invention relates to a method for generating a three-dimensional digital model of a drill core, comprising the steps of positioning at least one drill core fragment in an acquisition scenario; capturing images of the drill core fragment; generating a mask for each captured image; reconstructing the position and angle of the image; generating at least one dense point cloud; generating at least one polygonal mesh; georeferencing the drill core fragment; performing texture processing; and unifying a plurality of drill core fragments into a single three-dimensional object.
1 . A method for generating a three-dimensional digital model of a drill core, comprising the steps of:
positioning at least one drill core fragment, perpendicularly, on the center of at least one rotating base of an acquisition scenario, obeying the original lower and upper extraction positions of the drill core fragment from the reservoir;
wherein the original position of the base of the drill core fragment is arranged in contact with the surface of the rotating base;
wherein the rotating base is georeferenced by means of the north, east and altitude coordinates;
capturing images of the drill core fragment, in which an image is captured every 15° of rotation of the rotating base axis;
generating a mask for each captured image, including exclusion of all information other than the drill core fragment within the image;
reconstructing the position and angle of the image;
generating at least one dense point cloud;
generating at least one polygonal mesh;
georeferencing the drill core fragment;
performing texture processing; and
unifying a plurality of drill core fragments, including grouping the generated polygonal meshes into a single three-dimensional object within the same geographic reference system.
2 . The method according to claim 1 , wherein the acquisition scenario has a cubic shape with one of the faces open, and comprises an artificial lighting system and at least one stably positioned camera.
3 . The method according to claim 1 , wherein the north and east coordinates of the rotating base are individually calculated for each reservoir, and the altitude coordinate of the rotating base is dependent on the depth of the drill core fragment.
4 . The method according to claim 1 , wherein the rotating base and the drill core fragment are georeferenced through at least three targets, T1, T2, and T3, according to the equations:
T
1
x
=
C
x
equation
1
T
1
y
=
C
y
+
CT
1
_
equation
2
T
2
x
=
C
x
-
CT
2
_
equation
3
T
2
y
=
C
y
equation
4
T
3
x
=
C
x
+
CT
3
_
equation
5
T
3
y
=
C
y
equation
6
T
1
z
=
T
2
z
=
T
3
z
=
C
z
-
Fragment
dimension
equation
7
wherein:
C(x, y, z): flat cartographic coordinates of the position of the drilling hole in the well;
T1, T2, and T3: photogrammetric targets;
CT(1, 2, and 3) : distance between the center of the respective target and the center of the rotating base.
5 . The method according to claim 4 , wherein the north face of the drill core fragment is positioned according to T1.
6 . The method according to claim 1 , wherein twenty-four images are captured per fragment of the drill core.
7 . The method according to claim 1 , wherein reconstructing the position and angle of the image includes applying the Structure from Motion (SfM) algorithm to the image with the mask applied.
8 . The method according to claim 1 , wherein generating a dense point cloud includes using a Multi-View Stereo (MVS) algorithm.
9 . The method according to claim 1 , wherein generating a polygonal mesh includes using a Delaunay algorithm.
10 . The method according to claim 1 , wherein performing texture processing includes matching each pixel of the image with the surface of the polygonal mesh.
11 . The method according to claim 1 , wherein unifying the drill core fragments includes editing a three-dimensional object that contains vertex information, mapping textures and faces of a plurality of drill core fragments, and representing the plurality of drill core fragments in a continuous manner in a single three-dimensional object.
12 . A computer-readable storage media, comprising stored therein, a set of computer-readable instructions, which, when executed by a computer, executes the method as defined in claim 1 .