7 Deviated Wells

Contents

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2Data Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Defining Lines of Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3Graphically Defining a Line of Section for Deviated Wells . . . . . . . . . . . . . . . . . . . . . . . . . . 3Examples of Graphically Defined Sections for Deviated Wells . . . . . . . . . . . . . . . . . . . . . . . 4Spatially Defining a Line of Section for Deviated Wells . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6Using Shallow Suppression . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12Paradigm Rock & Fluid Canvas 2009 | Epos 4.0 Deviated Wells 7-1

Overview

Building and formatting deviated sections is the same as for standard sections. This section deals with the differences between standard and deviated section displays.

Data Preparation

Wells containing deviation data may be displayed in Section, providing certain logs existcheck the Reference set of each well. The X-offset, Y-offset and TVD (as well as the depth log) must all exist (see the documentation on Wellpath for information on generating these logs).Unlike standard wells, to view well deviation in Section, there MUST BE a line of section and the wells must be projected onto it. Additionally, Well Top and Well Bottom are the only valid Spacing options available to display the section.Deviated Wells 7-2Paradigm Rock & Fluid Canvas 2009 | Epos 4.0

Defining Lines of Section

As with standard wells, sections for deviated wells can be defined either graphically in Geologs Project applicationsee "Graphically Defining a Line of Section for Deviated Wells" on page 7-3, or spatially in Sectionsee "Spatially Defining a Line of Section for Deviated Wells" on page 7-6.

Graphically Defining a Line of Section for Deviated Wells

Graphically defining lines of section is done in Geologs Project application.

To graphically define a section for deviated wells1. In Project, open a Mapsheet and display the deviated wells.2. Select Format > Well Posting... and:

toggle on the Spider Deviation displayThe Spider display traces the path of the deviated wells as a surface projection and is useful in determining the best position of the line of section. See Posting on page 2-13 for further information.

change the Position to Bottom of WellAs the wells are often deviated from a central surface borehole, it is useful to display the wells at the well bottom to make it easier to select each well to project. Both the well symbol and well name will then be posted at the XY position of the bottom of the well, which should space out their display on the map. Click on the well symbol or well name to project the well onto the line of section.By default, Geolog projects the wells perpendicular to the line of section. If this is not possible, the projection will be adjusted to intersect the closest end of the line of section. Re-adjust the projection by dragging with the middle mouse button, ensuring the pointer is exactly over the projection line. Zoom in, if you have difficulty selecting points or lines.

3. See Graphically Inserting Sections on page 3-5, Modifying Section Lines and Projections on page 3-10 and Deviated Wells on page 2-16 in the Mapsheet documentation for further information on inserting and modifying sections, and projecting/snapping wells to a line of section.

Fig. 1 is an example of a line of section inserted for deviated wells.As the angle, position and proximity of the line of section and projections to the wells determines the final deviated display, it may be necessary to experiment with different lines of section and projection positions to optimize the final result.Deviated Wells 7-3Paradigm Rock & Fluid Canvas 2009 | Epos 4.0

Fig. 1: Line of section inserted and projections added for deviated wells on mapsheet

NOTE See Well order on page 3-13 and "Examples of Graphically Defined Sections for Deviated Wells" on page 7-4 for information on how the wells will be displayed in Geologs Section application.

Examples of Graphically Defined Sections for Deviated Wells

The length of the line of section, position of the projections on the line of section, and order in which the projections were inserted will determine the display when a line of section is opened in Geologs Section application. Fig. 2 and Fig. 3 show examples of line of section lengths and projection positions, and their resulting display.Deviated Wells 7-4Paradigm Rock & Fluid Canvas 2009 | Epos 4.0

Fig. 2: Line of section when projections are spaced along line

Line of section is long and projections are spaced along line.

Resulting display in Section (/(Datum, Scaling and Grid have been adjusted for clarity).

Spider display

ProjectionDeviated Wells 7-5Paradigm Rock & Fluid Canvas 2009 | Epos 4.0

Fig. 3: Line of section when projections converge along line

Spatially Defining a Line of Section for Deviated Wells

NOTE It is recommended that the section datum, spacing, layout, correlations, border and grid are defined PRIOR to turning on deviation display in Section (see "Display Deviation" on page 7-8).

Inserting and formatting segments, faults and fluid contacts is not available when Deviation display is toggled ON (see "Display Deviation" on page 7-8).

Specify Layouts and Spacing

1. Select Format > Spacing...2. Set the Spacing Option to WELL_BOTTOM.

Line of section is short and projections converge on line.

Resulting display in Section (Datum, Scaling and Grid have been adjusted for clarity)note wells overlap.

Spider display

ProjectionDeviated Wells 7-6Paradigm Rock & Fluid Canvas 2009 | Epos 4.0

3. Specify the deviated wells, layout(s) and set any other required optionssee Spatially Defined

Sections on page 2-13 for detailed information.

4. Select Section > Datum... and set the options in the Datum on page 1-9 dialog box as follows:Reference:set to Elevation(TVD); other references that can be used are TVT, TST, TIME and TWTIME.Datum:set to Elevation(TVD) for structural cross sections.Reference Grid Incrementsremove all values (set to blank) to simplify the display.

Fig. 4 is an example of a section display with a layout, spacing and datum options set.

Fig. 4: Section with layout, datum and spacing defined

Insert Correlations

Correlations and interpreted geological surfaces are inserted in deviated wells using the same procedures as those described in Working in Correlation Mode on page 3-1 and Working in Interpretation Mode on page 4-1.Following are some suggestions for simplifying the process:Deviated Wells 7-7Paradigm Rock & Fluid Canvas 2009 | Epos 4.0

Inserting and formatting functions for correlated and interpreted segments, faults and fluid

contacts are not available until the deviation display has been toggled OFF (Format > Wellbore...).

Select View > Layout Transparent and toggle off the transparency to provide better visibility of the logs.

Fig. 5 is an example of a section with correlations inserted.

Fig. 5: Correlations defined in Section display

Display Deviation

Deviation display is by default turned off (set to vertical) in Section.

NOTE The following logs must be in the Reference set in order for the cross section to display properly: DEPTH, XOFFSET, YOFFSET and TVD.

To display deviations1. Select Format > Wellbore to display the Wellbore dialog box.Deviated Wells 7-8Paradigm Rock & Fluid Canvas 2009 | Epos 4.0

2. Toggle on the Deviation option (see Wellbore on page 6-5 for further information on this dialog box).

NOTE Inserting and formatting segments, faults and fluid contacts is not available when Deviation display is toggled ON.

Fig. 6 is an example of a section display for deviated wells.

Toggle on to display well deviationDeviated Wells 7-9Paradigm Rock & Fluid Canvas 2009 | Epos 4.0

Fig. 6: Displaying deviation

Format the Display

See Formatting the Display on page 6-1 for information on how to change the appearance (e.g. grid lines, margins) of the section display.

Using Shallow Suppression

Where deviated well cross sections contain a number of wells with the same surface location, Shallow Suppression can be used to hide the display of all but one well from the top of the display to a specified depth limit. This is useful, for example, in offshore fields where an initial depth is not relevant to cross sectional analysis.Deviated Wells 7-10Paradigm Rock & Fluid Canvas 2009 | Epos 4.0

To set Shallow Suppression options

1. If required, toggle on Layout Details (View > Layout Details).2. Determine the depth to which you wish to limit the display of the wells.3. Select Format > Wellbore.4. Enter the name of the well you do not want to suppress in the Well to Draw field (see Fig. 7).5. In the Limit field, enter the value to which you wish to suppress all other wells. This value is

relative to the Reference Datum on page 1-9 setting [e.g. Depth, Elevation(TVD)].

Fig. 7: Shallow Suppression example

Set to create ShallowSuppression display.Deviated Wells 7-11Paradigm Rock & Fluid Canvas 2009 | Epos 4.0

Index

Ccorrelation

insert in deviated wells 8

Ddata preparation for

deviated well display in cross section 3datum

setting for deviated well display in Section 8deviated wells

data preparation for displaying in Section 3displaying in Section 2examples of graphically defined sections 5inserting correlations for 8select to project 4setting datum for 8

Pproject deviated wells to line of section 4

Ssections

create for deviated wells 2data preparation for deviated well display 3Deviated Wells 7-12Paradigm Rock & Fluid Canvas 2009 | Epos 4.0