The KOSUN SP Series stainless steel mixing pump provides instant hydration of polymers and bentonite. Discover how its axial turbine and pressure chamber eliminate “fish eyes” and reduce drilling fluid costs.

In modern drilling—whether at a remote onshore site or an autonomous offshore platform—the quality of drilling fluid determines everything. Its stability directly affects the rate of penetration, wellbore integrity, and ultimately the safety and efficiency of the entire project. However, preparing an ideal fluid is not simply a matter of mixing powders with water. It is a complex physicochemical process that requires powerful and controlled mechanical energy. This is where specialized equipment comes into play—mixing pumps. The KOSUN SP Series mixing pump is designed to meet the demands of the most challenging operating conditions.

Why a Conventional Pump Is Not Enough？

Standard centrifugal pumps are designed for transfer, not mixing. When powdered polymers (such as PAM, CMC, PAC) or bentonite are added to a conventional flow, the particles do not hydrate quickly enough and form dense gel lumps—so-called “fish eyes.” These lumps do not dissolve, clog shale shakers, and settle uselessly in tanks, increasing the consumption of expensive additives. Solving this problem requires a fundamentally different approach.

Innovative Hydrodynamics: Turbine and Pressure Chamber

KOSUN engineers have developed a design that differs fundamentally from traditional pumps. At the core of the SP Series is a combined system consisting of an axial-flow turbine pump and a specially designed horn-shaped pressure chamber.
 
How does it work?

The fluid entering the pump is accelerated by the turbine impeller to a high velocity. This high-speed stream is then directed through specially designed nozzles toward an impact plate. At the moment of impact, intense mixing forces are generated, instantly breaking intermolecular bonds and allowing polymer chains to fully extend and interact with water.
The result: complete elimination of “fish eyes” and a perfectly homogenized solution in a minimal number of cycles.

Materials That Ensure Long Service Life

Drilling fluid is an aggressive medium. Abrasive particles such as sand and barite, along with chemically active additives, quickly damage conventional cast iron components.
For this reason, KOSUN uses precision casting technology to manufacture the impellers and all wetted parts of its stainless steel mixing pumps. Stainless steel provides excellent corrosion resistance along with high mechanical strength to withstand continuous abrasive wear.
The direct benefits include extended service intervals and reduced downtime for maintenance and repair.

Reliable Operation Under Any Conditions: Low NPSH

One of the main threats to pumping equipment is cavitation. It occurs when suction pressure is insufficient—for example, due to low tank levels or elevated fluid temperatures. Cavitation damages impellers and seals, leading to premature pump failure.
Special attention has been given to optimizing the design for low NPSH (Net Positive Suction Head). As a result, the SP Series maintains stable, low-vibration operation even under challenging conditions where conventional pumps may fail.

Global Field Experience and Fast Return on Investment