October 23, 2024

ESP downhole disc filter – Reliable Protection for Long-Term Operation of Submersible Pumps

More than 60% of problems with submersible pumps arise due to the presence of solid mechanical impurities in reservoir fluids. They damage equipment, reduce production volumes, and incur additional maintenance and repair costs. The most common method of combating mechanical impurities has been the use of wedge filters; however, these devices are prone to rapid clogging and do not guarantee reliable protection for the installation.

Specialists from Novomet have developed a new volumetric device - ESP downhole disc filter. The design consists of a set of mesh rings mounted on a perforated shaft, which are manufactured using stamping. The size of the cells is chosen based on the required filtration fineness - 100, 200, 300, or 500 microns. The filtering element is made from corrosion-resistant material. The design of the filter is protected by a patent.

- The main advantage of the downhole disc filter is that filtration occurs not only on the surface but also inside the filter itself – in the mesh cells. In wedge filters, particles are retained only on the surface, allowing smaller clay particles to freely enter the pump and clog it, leading to faster blockage, - explains Yuri Korotkov, head of the design bureau for submersible pumps at Novomet. – At the same time, the downhole disc filter, providing high protection against mechanical impurities and extending the service life of the installation, wins in dimensions. Its length is 3-4 times shorter while maintaining the same necessary flow rates. Reducing metal consumption decreases weight and increases the overall resource of the submersible pump.

As a result of bench tests comparing clogging in wedge and disk filters of equal length with solid particle sizes of 0-200 microns, it was found that the throughput of the disk filter is 6-8 times higher. This is explained by the high specific area of open cells. The disk filter increases the service life of the submersible pump by 2-3 times, and in some cases even more.

The downhole disc filter easily performs its function in curved wells and in wells complicated by the carryover of mechanical impurities with an average particle diameter greater than 100 microns. It can be part of both compact submersible pumps of sizes 2A and 3 as well as the most common installations of sizes 5 and 5A. The downhole disc filter is mounted on a sealed casing or on the motor base (or Downhole ESP sensors) through a sealing unit.

To extend the service life of the submersible pump and ensure uninterrupted operation in the well, the filter can be equipped with a safety valve if necessary. This helps eliminate the risk of motor overheating during clogging of mesh disks. Additionally, one of the important advantages of the downhole disc filter is regeneration and multiple reuse. During scheduled maintenance or other instances when the installation is lifted to the surface, the filter can be cleaned and reused.

Overall, Novomet's downhole disc filter is currently the most successful and effective solution for protecting well pumps from mechanical impurities while maintaining reduced dimensional length and low hydraulic losses.