7/27/2019 3D Geological Modeling with Sketches and Annotations

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3D GEOLOGICAL MODELING W/ SKETCHES AND ANNOTATIONSRONAN MENDONCA AMORIM1, EMILIO VITAL BRAZIL1, DANIEL PATEL2, FARAMARZ SAMAVATI1, MARIO COSTA SOUSA1

1UNIVERSITY OF CALGARY 2CMR / UNIVERSITY OF BERGEN E-Mail: rmamorim@ucalgary.ca Web: http://ires.cpsc.ucalgary.ca/

CONTEXT: 3D GEO MODELING GOALS & METHODOLOGY

RESULTS

Constructing 3D digital geological models is a fundamental

task in O/G E&P. They serve as input to subsequent stages

in E&P cycles, including flow simulations.

Quality interpretation and representation of geo structures is

critical, in particular at early stages of E&P cycle.

3D rock structural and contact descriptions are typicallyinterpreted and represented as 2D aerial and cross-section

maps, containing a rich standardized set of symbols.

3D digital geo models built by users (modelers) based on

these 2D maps + interpretations, and on available data; a

complex task due to geological heterogeneities, limited data

availability, and multiple geological interpretation scenarios.

A critical stage in the existing 3D geo modeling workflow is

moving geo interpretations (usually 2D) into a digital 3D

geological model.

Specific case: (semi-) automatic horizon extraction from

seismic volume data, in current 3D reservoir modeling

workflow (little or no user-intervention)

Drawbacks in (semi-) automatic methods in current

modeling workflow: (a) data uncertainty and noise; (b) lack

of tools (with a natural interface) to allow direct user

interpretation, intervention, and data manipulation.

Manual intervention is a fundamental requirement for

creating good geological models [7], given the highly expert-

based interpretive nature of this task.

We present preliminary results of our sketch-based tool allowing the user to sketch directly on an existing 3D seismic volumetric model. This first prototype has already been

implemented and published [10]. Preliminary evaluation regarding the practical use of our prototype is very encouraging. Domain expert users who are working in collaboration in

this project expect improved turnaround times in seismic interpretation and subsequent geological model construction.

From interpretation Directly to 3D Geological Model

We propose a sketch-based approach [8] to narrow the gap between

the interpretation and modeling tasks as well as to allow the modeling

of geological heterogeneities in a more natural manner. Our main goal

is to mimic how domain experts interpret geological structures andallow the creation of models directly from the interpretation task,

therefore avoiding the drawbacks of a separate modeling stage.

Standard Symbols The proposed sketch-based interface will be based on standard

annotations of 2D geological maps and on

geologists' interpretation sketches. The 2D

sketching interface will allow the user to freely

draw conceptual geological structures on the

screen to capture his/her direct interpretation.

Coordinated Sketching Views. In our system we

intend to allow sketching on different views including

geological maps, cross-sections, and directly on the

3D. These multiple views will be coordinate in such a

way that modifications in one of them are reflected in

the others.

Geological Rules as Constraints. In order tocreate geologically correct 3D models, some

geological rules of formation and deformation

must be considered..

Examples of such rules are presented in

the figure below [9].

To create accurate geological models, one

must consider the existence of geological

rules to prevent geologically impossible

shapes, e.g., self-intersecting horizons.

Such rules will be responsible in the

proposed work for constraining directly the

input sketch when on map-view or cross-

section, or by means of methods such

collision detection, when on 3D sketch

mode. Such approach will allow to keep

the model consistent from the beginningreducing the need of posterior adjustments

when creating the simulation model.

Deforming a region of interest in three sketches: (a) user sketches a region of interest (red) over the

horizon surface; (b) a green sketch specifies a free-form cross-sectional cut in the seismic volume;

(c) a blue sketch defines the geometric deformation path of the underlying horizon surface.

Changing the topology of the horizon by painting holes on top of its surface

After adjusting the geometry and features of an automatically extracted horizon

(a), the user creates a new horizon by sketching across four seismic slices the

sketch is constrained by possible horizon profiles (black curves). A third horizon is

generated as a convex sum of the two existing ones (e).

[1]A.L. Coe et al. [2010] Geological Field Techniques . Wiley-Blackwell[2] Image from Dynamic Graphics, Inc.

[3] R.A. Chadwick et al. [2009] Review of Monitoring Issues and Technologies associated with

the Long-Term Underground Storage of Carbon Dioxide . Geological Society of London

[4] Image from the Government of South Australia

[5] D. Patel et al. [2010] Seismic Volume Visualization for Horizon Extraction . PacificVis 10[6] C. Engelsma, D. Hale [2010] Painting Seismic Images in 3D. SEG Tech. Program

[7] C. Gold [1980] Geological Mapping by Computer, p171. John Wiley & Sons.

[8] L. Olsen et al. [2009] Sketch-Based Modeling: A Survey.Computer & Graphics. 33(1): 85-103

[9]Adapted from: G. Caumon et al. [2009] Surface-based 3D Modeling of Geological Structures . Mathematical Geosciences

[10] R. Amorim et al. [2012] Sketch Modeling of Seismic Horizons from Uncertainty . SBIM 12