Static Pressure Editor

With the Static Pressure Editor (located within the Editors pane), you can add and manipulate static pressure data for entities, and view data at the group level. The content pane displays data for static pressure tests.

Note:   For multilayer wells, see Multilayer Wells: Static Pressure Editor Differences.

User Interface

In the table, there is a vertical black line separating columns on the left that are always displayed, and columns on the right that can be selected / deselected by clicking their checkboxes in the Editors pane. Above the table is sandface and datum depth information.

For static pressure tests, Test Date and Run Depth Pressure are required. Based on this data, the run depth pressure is used as the sandface and datum pressures.

Note:   You must enter static pressures to perform a static Material Balance analysis.

To provide better data for the analysis, a run depth should also be provided. This is the depth at which a static pressure is measured. This can be used in combination with the sandface depth (or MPP) and the datum depth to determine pressures at these depths. In order to calculate sandface pressure, provide either a Run Depth Pressure Gradient or fluid properties in the Properties editor.

When a single well is considered, the sandface and datum depths are considered to be the same, and the same pressures are calculated for both columns. For a group of wells, sandface depth is likely different for each well, and a common datum is used as the depth for converting pressures. When viewing the static pressure data for the group, the calculated datum pressures are displayed differently from the values viewed under each well.

There are two possible sources of data for sandface and datum depths used in the Static Pressure Editor:

1. User input in the Wellbore editor — You can specify perforation intervals, and a MPP depth is calculated.

2. Imported files — Some file types such as .mer files contain KB elevation for wells, and the perforation intervals reported for pressure tests. These values are used as depth values at the top of the Static Pressure editor unless you overwrite these fields.

Header

These items are displayed above the table in the main pane:

• Top Perf (TVD) — the uppermost perforation depth from the Attributes tab or the Wellbore editor. (The Wellbore editor's perforation interval inputs override the Attributes tab's inputs.) The top perf depth is converted from measured depth (MD) to true vertical depth (TVD) based on the Deviation Survey entered in the Wellbore editor.
• Bottom Perf (TVD) — the lowermost perforation depth. The bottom perf depth is converted from MD to true vertical depth TVD based on the Deviation Survey entered in the Wellbore editor.
• Sandface Depth (TVD) — the midpoint of the perforated interval (MPP). You cannot change the Sandface Depth in the Static Pressure editor by changing the Datum Depth in the Wellbore editor. It is calculated based on top and bottom perf inputs (form the Attributes tab or Wellbore editors) only. You cannot type a fixed reservoir datum depth.
• KB Elevation — the kelly bushing (KB) reference elevation. All datum calculations reference the KB elevation.
• Datum (msl) — the true vertical depth relative to mean sea level (msl). This value changes depending upon the launched entity as described below:
  
  
  • For Well entities: "Datum" depth is always the Sandface or MPP depth in TVD for the well. This is not the Datum Depth referred to in the Wellbore editor.
  • For Group entities: "Datum" depth is calculated from the average well Datum Depths of the wells in the group. As group membership changes, the group datum depth changes. The intention is to automatically minimize the Datum Depth correction required for each well in the group. You cannot type a fixed reservoir datum depth.

Column headers

Column headers are defined as follows:

• Static Run Depth Pressure — the gauge measured pressure in absolute pressure units.
• Run Depth — the depth of the gauge used to measure the static pressure.
• Static Sandface Pressure — the Run Depth Pressure corrected to the Sandface Depth or MPP of a launched well entity.
• Static Pressure at Datum Depth — the Run Depth Pressure corrected to the Datum Depth for a launched group entity. You cannot type a fixed reservoir datum depth. The Static Pressure at Datum Depth for a well entity, or a group with only one well, is always the same as the Static Sandface Pressure. The Static Pressure at Datum Depth and the Static Sandface Pressure are only different when there are multiple wells in the group with differing MPPs based on datum depths.
• Effective Gradient is either:
  
  
  • (a) the “Run Depth Pressure Gradient” you entered, or
  • (b) An internally calculated gradient based on the specified Primary Fluid in the Attributes tab, the input Run Depth Pressure, the reservoir temperature in the Properties editor, as well as inputs in the Wellbore and Fluid Properties editors.
  • We use (a) when the Run Depth Gradient contains a non-zero value
  • We use (b) when the Run Depth Gradient contains a zero, or is blank.
• Static Wellhead Pressure— you can type a value for information purposes. In rare circumstances, we have only measured well static pressure data and no gauge measured data. In those cases, you can copy / paste the Static Wellhead Pressures over to the Run Depth Pressure column. If you specify a Run Depth of "0" (zero) and set the Primary fluid to gas, oil, or water, Harmony calculates Sandface and Group Datum pressures based on sandface depth (MPP) and the Effective Gradient. This method can be used for gas, oil, or water, but generally should only be used for gas. It also assumes there are no wellbore or reservoir fluid contacts between the wellhead and the calculated datum depth.
• Run Depth Pressure Gradient — the pressure gradient measured at or near the gauge depth in the wellbore. You should be careful when using imported values, as these gradients generally reflect wellbore fluid contacts, and not necessarily the fluid contacts in the reservoir.

Note:    The remainder of the column headers are provided for information only, and are not used in the calculations.

Multilayer Wells: Static Pressure Editor Differences

Single-layer wells vs multilayer wells are contrasted below:

• The Static Pressure Editor is available to the well entity of a multilayered well, but it is not available to layer entities.
• Layout changes for multilayer wells: None
• Functionality changes for multilayer wells: None