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K-A End User Help

BHP Workflow

The BHP workflow converts pressure measured at a certain gauge depth to the pressure at the desired depth, usually converting Well Head Pressure (WHP) to Bottom Hole Pressure (BHP). To create a BHP workflow, some essential information is required, including Wellbore and PVT objects, specific well properties, pressure gauge and rates. For gas lift cases, additional information must be provided, including PVT data and gas injection rates.  

Flow Path Assumptions

The BHP workflow assumes, by default, that the flow path is through the tubing when the wellbore configuration includes a defined tubing string and a Tubing Head Pressure (THP) is available. If tubing is not defined, the workflow defaults to assuming flow through the casing, using the Casing Head Pressure (CHP) as the reference for pressure calculations. When the flow path is known, it should be defined during the wellbore creation.  

Temperature Profile

Temperature is linearly interpolated with measured depth (MD) between the known wellhead and bottomhole temperatures. This approach accounts for wellbore deviation since measured depth follows the actual well path. As a result, the temperature profile is generally nonlinear when expressed against true vertical depth (TVD) in deviated wells.  

Available Flow Correlations

The pressure at the target depth is estimated using various correlations, The available flow correlation options depend on the selected PVT fluid type, as shown in the table below:

Note

Stanford Drift Flux is the default primary correlation. Additional correlations can be selected via the Additional correlation types dropdown in the BHP creation dialog. The number of output channels depends on how many correlations are selected.

Prerequisites

The following conditions must be met prior to executing the BHP workflow:

  • A Wellbore object exist under the well.

  • A PVT object is defined under the well.

  • The required properties are defined under the well properties.

BHP workflow activation

The BHP workflow is activated when a wellbore object is created. For time-dependent completions, where the wellbore geometry changes over time, a separate geometry must be defined for each date on which a change occurs. This ensures an accurate representation of the well throughout its productive life.

Inputs

To run the BHP workflow, the following information must be provided:

  • PVT

    Define the PVT object for any reservoir fluid. The PVT object is created via the PVT service, which extracts PVT data from any KAPPA-Workstation STR document. The PVT object can also be created from PVT files (e.g., .ebo, .kbo) using the KAPPA-Automate SDK. For gas lift cases, a separate PVT object must also be defined for the injected gas.

    PVT_inputs.png

  • Pressures gauges

    At least one pressure gauge must be provided, either Casing Head Pressure (CHP) or Tubing Head Pressure (THP). For time-dependent completions where the flow path changes from casing to tubing, both CHP and THP are required. Downhole pressure gauges are also supported as inputs for the BHP workflow.

    Pressure_Gauges.png

  • Rates gauges

    Define the input surface rates gauges: oil rate (qo), gas rate (qg), water(qw). For gas lift cases, also define the injection rates gauge (qgi).

    Rates_gauges_in_BHP_workflow.png

  • Well properties

    The BHP workflow requires specific well properties. These properties are mandatory and the workflow cannot be executed if any are missing.

    1. Thermal Properties: The following temperature parameters must be defined:

      • Wellhead Temperature (WHT)

      • Bottomhole Temperature (BHP)

    2. Flow Type Parameters: The following multipliers must be specified to account for pressure loss due to elevation and friction:

      • dp/dl Elevation Multiplier.

      • dp/dl Friction Multiplier.

        If the multipliers are not defined, they will be assigned default values of 1.0.

    3. Target Depth: Pressure conversion requires at least one depth value to be defined in the Well Properties. This can include perforation depth, reservoir depth, or any other reference depth.

      Depths.png

Viewing BHP Workflow Results

When BHP workflow is first launched, it will create a new folder called KW workflows in the field hierarchy, with the BHP Workflow results listed there. Depending on the selection of output gauges when creating the BHP Workflow, the computed pressures are created under the parent well:

BHP_results.png

One can run several workflows in parallel and compare them.

BHP Workflow plot

It is also possible to view the BHP Workflow result as a plot. To do so:

  • In the well node, click on the workflow folder.

  • Click on BHP Workflow node, then switch to the plot tab.

The plot displays the input pressure (WHP) alongside the computed BHP output channels, allowing direct visual comparison.

BHP_plot_results.png
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