Formation Inputs

How to add pore- and fracture pressures, collapse pressure, formation temperature and lithology in Oliasoft WellDesign.

When entering the Formation Inputs section, you will see the following page containing the five tabs called Pore Pressure, Fracture Pressure, Collapse Pressure, Formation Temperature and Lithology Table.

Pore/Fracture/Collapse Pressure

The Pore Pressure, Fracture Pressure and Collapse Pressure tabs all display a table to the left and a chart to the right, as seen in the figure above. The chart will be updated automatically as new pressure gradients are added to the pore/fracture/collapse pressure tables.

The pore, fracture and collapse pressures can be added in three ways, either by inputting gradients manually, using copy & paste or by importing a file. These methods will be further described in the following tabs.

By clicking on the + button, marked with a one in the figure below, a new row will be added to the table. As seen in the figure, a depth (TVD) and pressure gradient must be defined in each row.

New rows can also be added above and below a specific row by clicking on the more button, which is marked with a two in the figure. This button also provides the option to delete that specific row from the table.

To paste and import data to the pressure tables, the data copied to your clipboard/found in the file to be uploaded must contain a specific structure. A further description of this structure is given in the following paragraphs.

Required Structure of Data to be Pasted or Uploaded to the Pressure Tables

To paste and import data to the pressure tables, the data must have the following structure.

As seen in the figure, the depth (TVD) and pressure gradient inputs must be placed to the left and right in the table, respectively. In addition, the first row of the data to be pasted or uploaded must contain the applied units. This could be either m, ft, km, in or mm for depth or sg, ppg, kg/m3, lbm/ft3, g/cm3 or lb/ft3 for pressure.

In Oliasoft WellDesign, the pore-, fracture- and collapse pressures are defined from the seabed to the top of the reservoir. This means that the first row in the pressure table will represent the depth and the pressure gradient at the seabed, whereas the last row represents the depth and pressure gradient at the top of the reservoir.

As will be seen in the application, the first row in the pressure tables will be calculated and filled out automatically when designing an offshore well. These calculations are based on the Well Configuration data given in the Project Settings section.

Formation Temperature

When entering the Formation Temperature tab, you will see the following page. As seen (1), there are two options to choose between when defining the formation temperature; Linear and Temperature at TD. These will be further elaborated in the tabs below.

When choosing the Linear option for defining the formation temperature, you will see the page displayed in the figure above and the following must be defined:

  • Drill floor temperature

  • Seabed temperature

  • Geothermal temperature

As seen, marked with a two in the figure above, the geothermal temperature can be defined in three ways - either as a temperature gradient, temperature at total depth or temperature at a specified depth.

Required Structure of Data to be Pasted or Uploaded to the Formation Temperature Table

To paste and import data to the formation temperature table, the data must have the following structure.

As seen in the figure, the depth (TVD) and temperature inputs must be placed to the left and right in the table, respectively. In addition, the first row of the data to be pasted or uploaded must contain the applied units. This could either be m, ft, km, in or mm for depth or °C or °F for temperature.

Lithology Table

When entering the Lithology Table tab, you will see the following table where the rock types that make up the formation can be defined.

As before, new rows are added by clicking the + button, which is marked with a one in the figure. The Rock Type input, marked with a two in the figure, must be selected from a drop down list, whereas the other input fields can contain the text/values of your choice.

The Rock Type drop down list contains components from the Formation Properties library, which is found in Libraries.

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