Wahal High shear jet mixers, often called “jet mud mixers” are essential equipment in the oil and gas industry for the preparation and maintenance of drilling fluids (also known as “drilling muds”). These specialized mixers are designed to efficiently blend, disperse, and emulsify various components to create a fluid with specific, critical properties.
The Role of Drilling Fluids
Drilling fluids are complex, custom-engineered fluids that serve several vital functions during drilling operations, including:
- Carrying Cuttings: Transporting rock cuttings from the bottom of the wellbore to the surface.
- Controlling Formation Pressure: Maintaining hydrostatic pressure to prevent the wellbore from collapsing and to control the flow of formation fluids.
- Lubricating and Cooling: Reducing friction and heat generated by the drill bit and drill string.
- Providing Wellbore Stability: Forming a filter cake on the wellbore walls to prevent fluid loss and stabilize the formation.
The precise performance of the drilling fluid is directly tied to the quality of its components and how they are mixed. This is where high shear mixers play a crucial role.
How Wahal High Shear Jet Mixers Work for Drilling Fluids
High shear jet mixers for drilling fluids are typically designed as a system that includes a centrifugal pump, a mixing hopper (or “Venturi” hopper), and a network of pipes and valves. The key principles are similar to other high shear mixers, but the application is highly specialized:
- High-Velocity Recirculation: The centrifugal pump circulates the base fluid (usually water or oil) from a mixing tank or mud pit.
- Venturi Effect: The fluid is pumped at a high velocity through a nozzle, creating a low-pressure zone in the mixing hopper.
- Additive Induction: This low-pressure zone creates a powerful suction, drawing solid additives (like bentonite, barite, or polymers) from the hopper into the fast-moving liquid stream.
- Intense Shearing: As the mixture is forced through the confined space of the nozzle and diffuser, it experiences extreme turbulence, cavitation, and hydraulic shear.This intense energy breaks down solid agglomerates, hydrates polymers, and emulsifies oil and water, ensuring a uniform and stable mixture.
- Continuous Circulation: The high-velocity jet stream then re-enters the main tank, creating a powerful mixing action that circulates the entire volume and ensures a homogenous blend.
