Novel Multi-Functional Chemical Technology for Sand Consolidation, Relative Permeability Modification and ESP Run Life Extension
Authors: Shevelev Pavel , Kazempour Mahdi , Survenev Sergey , Do Linh , Shields Robin , Sutherland Louise , Lee Jesse , Street Paul 
Published: February 2022

Sand production in unconsolidated reservoirs has been an ongoing issue leading to significant reduction in well productivity, costly remediation, and damage to production facilities. This pape r introduces two novel chemical-based technologies, one water and one oil-soluble, that were designed to reduce operational complexities, improve reliability, extend ESP run life and offer critical benefits such as reduced relative permeability to water with minimal impacts on oil production. These technologies can be applied in wide range of reservoir conditions, from low (down to 15 °C) to high temperature (up to 110 °C) and can be deployed for both vertical and horizontal wells.

In this study, a novel protocol and apparatus for sand migration study was developed. Sand packs with different sand sizes (100, 60 and 40 meshes) were prepared and tested under different pressure gradients to simulate various downhole environments. The impacts of water composition and temperature were also explored. The sand consolidation performance was quantified based on amounts of sand produced with and without treatment in conjunction with pressure drop profiles. The set up was then modified to measure effective permeability after chemical treatment. More than one hundred field trials were conducted using the oil-soluble technology to validate the laboratory findings.

The laboratory results demonstrate that both oil and water-soluble technologies are effective in reducing sand production significantly. Performance of the water-soluble technology is a function of additive concentration and temperature; higher temperature environments require higher concentrations of the chemical additives. On the contrary, the oil-soluble technology is relatively insensitive to temperature variation and thus consolidation efficacy remains constantly high within the applicable range. Most importantly, both technologies significantly reduced water mobility (&gt; 50%) in which the oil mobility reduction was merely less than 10%. The success rate of the oil-soluble technology is greater than 90% based on field result (&gt;100 field trials) including low temperature reservoirs and selected sections of long horizontal wells. It is important to note that the oil-soluble technology, once pumped and set downhole, is no longer oil soluble therefore has been successfully deployed in oil reservoirs. This technology has also been shown to significantly reduce the maintenance frequency of electrical submersible pumps (ESP) and thus significantly extended run lives are observed. In certain cases, the frequency of cleaning out sand was reduced from several days to more than one year. Field observations also indicate that oil production rates were increased (&gt;15%) and sustained for 2-3 months.

The results of this study provide helpful information on using chemical-based technologies to address sand production issues in a wide range of reservoir temperatures with a high success rate. The novel technologies introduced here not only are effective for sand consolidation and extended ESP run life, but also efficient as relative permeability modifiers.