User guide of rock modeling module

1 Quick look

1.1 Introduction

The major function of rock module is to build the geometry of complex intrusions (including volcanic

intrusions and salt dome), rock modeling module is a supplementary function of structural modeling

module. Structural modeling module mainly deals with the faults and horizons modeling. Though it

could make some simple rock models, it has its own limits, such as:

1) The relationships between rocks should not be too complex;

2) The amount of the rocks is quite limited;

3) The size of rocks should not be less than the horizon grid;

4) When generated, the surface is extended to the whole survey.

Rock modeling module, by contrast, can cover the shortages mentioned above:

1) It has the ability to make any complex rock according to the strike of rock or data;

2) It has no limitation on the amount of rocks;

3) The size of rocks depends on the precision of interpretation;

4) Each surface will be generated in a local coordinate system, usually confined within a small

volume. The sub model will be inserted and merged into the structure framework automatically.

The general strategies of building rock model is use targeted methods to modeling by the shapes of the

complex rocks. The rock modeling module performs the functions of making platy rock, columnar

rock and complex rock, it can able to establish the corresponding shape of intrusions quickly and

efficiently. For particularly complex intrusion, no way can be used by any of above three methods, the

best way to solve this problem is split the complex rock mass, set up them separately by targeted

approach. After the separated modeling have finished, link them automatically, the complex rock mass

is completed.

In rock modeling module, the intrusion is divided into three types: platy rock, columnar rock and

complex rock.

The Identifier of platy intrusion: platy rock mass extend very long along two directions (length and

width), and other one direction is very short, just like the sheet dike, sill as shown in the following

(Fig. 1-1), the intrusion similar to plate because of the rock was restricted by strata and faults.

 

Fig. 1-1 Platy intrusion.

The identifier of columnar rock: rock mass extends very long on one direction, while other two

directions are very short, just like the apophysis as shown in the following figure(Fig. 1-2a), under

the pressure of strata, the inversion was extend on one direction and formed like tree. The

volcanic pipe also can describe by columnar rock.

(a) (b)

Fig. 1-2 Intrusion.

The identifier of bulk rock: it takes large space, extends similar scale in three direction, just like

batholith and stock in the above figure (Fig. 1-2a).

For particularly complex intrusion, it combination of varieties of forms together (Fig. 1-2b). So

user can split the complex rock mass, set up them separately by targeted approach. As shown in

the picture below, division the inversion into one bulk rock , two platy rocks and three columnar

rocks（Fig. 1-3）.

Fig. 1-3 Schematic of building complex intrusion by segmentation modeling.

1.2 Module relationships

The structural interpretation module provide seismic data and interpret data for rock modeling

module. Through define the cross-cutting relationship to process the truncation of rock model, in

this sense, rock modeling module is a subset of structural modeling module. As shown in the (Fig.

1-4).

 

Fig. 1-4 Relationships between the rock modeling module and other modules.

1.3 Work flow

There have three types of data sources for intrusion modeling: data1 is the interpreted data

provided by structural interpretation module, data2 is the interpreted data provided by intrusion

modeling module, data3 is the point data provided by other software.Data1 and data3 can load

into the intrusion modeling module directly. Base on model size and the amount of data to set the

grid, generate the surface before create the model.Data2 Interpret data in intrusion modeling

module, use geological plan, structure section and fault surface for reference plane, drawing the

outline of intrusion, extract points which was in the specified range, generate the intrusion model.

The work flow of building intrusion modeling is as follow (Fig. 1-5):

 

Fig. 1-5 Workflow of rock modeling.

2 How to building rock model

Please refer to training video for rock modeling module.

3 Special topic

3.1 How to choose the appropriate one from three methods of

rock mass modeling?

Rock mass module has three methods: platy rock mass modeling, columnar rock mass modeling

and complex mass rock modeling. Based on shape of the rock mass, different modeling methods

are chosen.

1) Columnar rock modeling method: rock mass extends very long on one direction, while other

two directions are very short, showing column shape. The columnar rock mass modeling method

is chosen as the chart below. (Fig. 3-1);

 

(a) (b)

Fig. 3-1 Columnar rock modeling method.

2) Platy rock modeling method: Platy rock mass extend very long along two directions (length

and width), and other one direction is very short, showing column shape. The platy rock mass

modeling method is chosen as below chart (Fig. 3-2);

 

(a) (b)

Fig. 3-2 Platy rock modeling method.

3) Bulk rock mass modeling method: the complex rock has a single one boundary surface, it can

be directly model (Fig. 3-3).

 

Fig. 3-3 Bulk rock model.

If it has more than one of that, you split the complex rock mass, and next set up them separately.

Finally, the complex rock mass is completed as the chart below (Fig. 3-4).

 

Fig. 3-4 Complex intrusion model.

3.2 How to adjust the platy rock local form?

Establishing platy rock mass, the Key points start the App. Key points are selected on the surface of

rock mass, and thickness is set in the attribute column. The discrete points are extracted in the Top

key points, Make surface (Fig. 3-5 c).

(a) (b)

 

(c)

Fig. 3-5 Adjust the platy rock local form.