Perforation Gun evaluation workflow with PipeSim

As we all know, perforation in oil and gas wells involves shooting a shaped charge through the well's casing and cement to connect the wellbore to the reservoir formation. (Interestingly, shaped charge technology is also used in RPGs and other military weapons.)

This article outlines a workflow for comparing perforation penetration in PIPESIM by SLB to select the optimal perforation design for oil and gas well completions.

Step 1: Enter Well Configuration

Input the well configuration data as usual, paying close attention to the "Tubulars" and "Completion" tabs. Accurately input casing OD, wall thickness, casing grade, borehole diameter, cement top, and density, as these parameters significantly influence the penetration simulation results.

Step 2: Perforation Design

Up in the ribbon, select “Perforation Design” for us to enter additional “Wellbore” and “Rock Data” as well as to select the “Gun Systems” to evaluate.

Wellbore:

• Input the completion depth, wellbore fluid present at the time of the perforation (please, dont let it be mud!) and its density.
• Tubular data will update based on Step 1 input.
• Specify gun positioning (centralized, positioned or not) as needed.

Rock Data:

• Input reservoir and rock data.
• Pay special attention to rock strength and vertical stress, as they significantly impact perforation penetration. Consult with your G&G colleague if necessary.

Damaged Zone:

• Estimate the depth or thickness of mud invasion into the formation.
• This can be calculated volumetrically from cumulative mud leak-off data. The total lost mud volume can be converted into radial mud penetration with the volumetric formula for a cylinder (content for another post).

Step 3: Gun Systems

• Access the gun catalog by clicking the (...) in the Gun Systems tab.
• Select guns based on charge type, OD, weight, and phase angle.
• Choose the correct explosive type (RDX, HMX, HNS, PYX).
• Select one gun per row for the simulation.

Click "Run" to start the perforation simulation.

Results.

Now take a look at the resulting penetration depth and hole diameter for the selected gun systems. The resulting table and the penetration plots will be helpful in the evaluation of the guns to use.

In this example, I compared the penetration of a 4 1/2" OD gun versus a 2 1/4" OD gun, clearly showing the advantage of perforating with a heavier charge, larger gun.

Use the resulting data as input for the inflow performance relationship to estimate reservoir deliverability for your production calculations.