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Parent-Child Interference Module Config

Parent-Child Interference Module: User Guide

In unconventional oil and gas development, a new well (the “child”) placed too close to an older, producing well (the “parent”) often suffers a permanent drop in production due to pressure depletion. This tool helps you intuitively model, visualize, and calculate that production drop across your entire field.

This guide explains how to use the PARENT-CHILD CONFIG tab to set up interference rules, and conceptually explains how the math operates behind the scenes without the technical jargon.

1. Getting Started: The Master Switch

When you click on the PARENT-CHILD CONFIG tab in the center of the screen, you’ll see a dashboard with your main controls.

  • Enable PC Effects: This is your master switch.
    • ON: The tool checks every well in your schedule, finds out if it was drilled too close to an older producing well, and applies a penalty.
    • OFF: All wells will produce at 100% of their base type-well curve.

Important: Always remember to click the blue Apply & Recalculate button at the top right (or lower left) after making changes. The application will instantly re-run the entire field forecast and update the charts.

2. Choosing the Interference Mode (How We Detect Intersections)

Before applying a penalty, the tool needs to figure out what counts as a nearby well. Because wells are long 3D paths, checking distance isn’t as simple as checking surface locations. We define this using three Modes:

Perpendicular Mode (Center-to-Center)

  • What it does: Measures the distance between the physical middle of two horizontal well segments.
  • When to use it: Good for standard side-by-side pads. This is the classic “well spacing” check.

Parallel Mode (Closest Overlap)

  • What it does: Checks the absolute shortest distance between any two overlapping parts of the two well laterals.
  • When to use it: Perfect for staggered well patterns, wells drilled end-to-end (“toe-to-heel”), or crossing paths. Even if the middle of the wells are far apart, if the tips touch, this mode catches it.

Cross-Layer Mode

  • What it does: By default, wells only steal production from other wells located in the exact same landing zone (e.g., an L1 well only hurts another L1 well). Turning this ON allows wells in different vertical elevations to interfere.
  • When to use it: If your fracs usually break out of their zones and communicate with layers above or below them.

Pro-tip: You can toggle multiple modes at once! The tool will test them all and automatically pick the closest, most severe distance it finds for its calculations.

3. Defining the Risk Zone (Distance Threshold)

  • Distance (m): Input the maximum radius of your typical frac hit (e.g., 450 m).
  • How it calculates: Behind the scenes, the tool draws a bubble of this radius around the parent well. If a child well is placed further away than this number, it is considered “virgin rock” and takes 0% penalty no matter how long the parent has been producing. If it falls inside this distance, the penalty kicks in.

4. The Child Degradation Curve

If a well falls into the “danger zone”, the tool applies a penalty based on Time. A parent well that has been producing for 4 years has depleted much more pressure than a well producing for 4 months.

The interactive Child Degradation Curve chart allows you to map this out:

  • Horizontal Axis (Age): How many months the parent well was actively producing before the new child well was turned on.
  • Vertical Axis (Factor): The percentage of production the child gets to keep. 1.0 means 100% (no penalty), and 0.5 means 50% loss.

How to Edit the Curve:

  1. Look at the Point Details table on the right side.
  2. Click + Add Point to create a rule. For example: Set Age = 24 months, Value = 0.85 (Meaning: a 2-year-old parent well causes a 15% drop).
  3. The curve on the left will instantly update, drawing a smooth, intelligent line between your points so you don’t have to define every single month.
  4. Click the red x next to any point in the table to delete it.

Keep it realistic: The curve should slope downwards. The longer a parent produces, the harder it should be on the child well.

5. Reviewing the Results

Once you hit Apply & Recalculate, you can verify the results easily natively in the UI:

  1. Check the PAD SCHEDULE Table (Right Panel):

    • Click the expand arrow (>) next to any pad to see its wells.
    • Look at the PC (%) column. You can instantly see exactly which wells were penalized (e.g., 85%) and which escaped interference (100%).
    • The EUR Oil/Gas numbers automatically reflect this exact multiplier.

  2. Check the Spatial View (Center Panel Tab):

    • Switch to the Spatial View tab.
    • As you scrub the timeline, producing wells will be color-coded. A severely penalized child well will glow Red or Orange, while unaffected wells show up as Green.

  3. Check the Production Chart (Bottom Panel):

    • The field-wide production chart at the bottom is mathematically exactly equal to the sum of all individual wells. You’ll see a visible dip in the field’s aggregate production line directly reflecting the penalties you applied across the schedule.