Flowback Causes Serious Issues for ESPs

Many types of artificial lifts are utilized in oil fields across North America to increase the flow of production liquids to the surface. One of the most effective types of systems commonly used is an electric submersible pump (ESP). ESPs are used in wells with low gas/oil ratios, bubblepoint, or bottomhole ratios in addition to wells with a high water cut or low API gravity fluids. Many improvements over the years have led to an increased use of ESPs, which are considered economical and efficient on a cost-per-barrel basis.  

Over the life of the well, the ESP is exposed to many different factors that can impact the pump’s performance. One very common issue is abrasion caused from solids production, specifically from proppant flowback. In the early stages of production, especially when an ESP is just installed, proppant flowback is typically at its highest rate of occurrence.

In order to achieve a good ESP run life, it is important to control the exposure of the ESP to proppant flowback. One of the most common ways to achieve this is through the use of curable resin coated sand (CRCS). Under temperature and closure pressure, the CRCS will bond to form a pack which controls sand production in addition to maintaining frac width and enhancing permeability.

Often the completion engineers will use uncoated frac sand (UFS) as a cheaper alternative to CRCS to control completion costs, but UFS does not provide flowback control. This problem will lead to a higher occurrence of ESP damage and significant additional repair and replacement costs incurred on the production side. Lost production from downtime must also be taken into account as well as a possible decrease in reservoir performance that may never be regained. Costs will vary based on equipment type and field location, but some of the common costs associated with each ESP damage occurrence are listed below.

  AFE Expense   Cost  
ESP Replacement   $100,000
Workover Rig (3 days)   $30,000
Trucking/Dock Services   $6,000
Rental Tools & Equipment   $5,000
Contract/Service Labor   $4,500
Test/Inspect Pipe   $2,000
Insurance (2% total)   $2,950
Contingency Costs (10% total)   $14,750
     
Total   $165,200
Production Downtime   3 days lost

 

While it is important to control completion costs, damage and replacement of ESPs are shown to have significantly higher costs and can easily be prevented with the use of a CRCS. This example was only the cost of one occurrence, but many can happen over the life of the well. Have you calculated what proppant flowback is costing you?

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