ENVIROTHERM NT

Optimize drilling and minimize environmental impact in high-temperature applications with the next generation water-base drilling fluid system

The ENVIROTHERM NT system is the result of three simultaneous operator demands. We have consistently received requests for a single drilling-fluid system that is chrome-free for environmental reasons, that can resist bottomhole temperatures in excess of 450° F (232° C) and that uses water-base chemistry. Their requirements stem chiefly from traditional land-based operations, but now high-temperature shale drilling has the same requirements for certain areas.

The system is a successful, field-proven HTHP water-base fluid and has been used under very severe conditions — to more than 350°F (177°C). It maintains its stable properties not only while drilling, but also during the prolonged static conditions experienced during tripping, logging and testing operations. The ENVIROTHERM NT system is characterized by low and stable rheological properties, low HTHP fluid loss and minimizes hole problems, providing shale inhibition and resistance to contamination for extreme conditions of density and temperature.

Features

• Easily managed in the field
• Excellent shale inhibition
• Water-base, chrome-free chemistry
• Stable at high temperatures
• Stable rheological properties
• Resists contamination
• Flexible formulation that can be adapted as temperatures increase
• Reduces the need for dilution

Benefits

• Reduces NPT
• Maintains optimum ROP in highly compacted/hard shales
• Environmentally acceptable worldwide
• Reduces pressure spikes caused by gelation
• Less time spent treating the system
• Drilling can proceed in a range of conditions
• Economical to use, as fluid formulation can be customized for various temperature ranges
• Less waste for disposal

Applications

High-temperature (HT) wells, including those in shale plays and any project that is environmentally sensitive, experiences high temperatures and that requires a water-base drilling-fluid system.

Problems

High temperatures often cause clay-base systems to gel, and the pressures required to break these gels can cause wellbore damage. Many of the previous HT systems were based on chemicals that have been declared environmentally unsafe.

Solutions

The polymer-base ENVIROTHERM NT system resists gelling at high temperatures and its water-base formulation meets environmental standards worldwide.

Economics

The absence of HT gelation means better drilling conditions and fewer pressure spikes. The system also reduces cuttings-disposal costs, and it can be reconditioned and reused.

Environmental

The system uses environmentally acceptable chemicals that deliver optimal results while significantly reducing waste generation.