Trias Westland’s geothermal operator faced severe corrosion and injection challenges across several projects with similar casings and reservoir fluids. In response, Sproule developed novel well completion design featuring a Glass Fibre Reinforced Epoxy (GRE) composite casing, effectively combating corrosion. Since its successful installation in 2019, this innovative design has set a new industry benchmark. In 2023, Nature’s Heat, a geothermal operator facing integrity challenges, also adopted the GRE-lined tapered retrievable string, benefiting from Sproule’s project management and engineering expertise.
Project Highlights
- Glass Fibre Reinforced Epoxy Casing
- Environmentally Friendly Corrosion Prevention
- Custom Tubular Design and Installation
- Reduced Corrosion and Improved Injectivity
Challenge
The Impact on Production: Corrosion (e.g., ferrous sulfate, microbial-induced, etc.), erosion, scaling, and injection clogging, significantly affect well integrity and productivity, leading to increased maintenance costs and downtime.
Limitations of Corrosion Inhibitors: Corrosion inhibitors present uncertainty and environmental concerns, raising questions about their long-term viability in geothermal applications.
Material Selection: While corrosion-resistant options like 13Cr are effective, they are costly. Composite materials, like GRE, require careful handling due to low torque connections and limited compressive strength.
Solution
The GRE Advantage: Large-diameter GRE tubing is resistant to aggressive geothermal water chemistry, preventing integrity issues while maintaining high-pressure injection rates.
Enhanced Monitoring Capabilities: Utilizing GRE as an inner string allows for advanced leakage detection, enhancing well integrity and promoting responsible geothermal operations.
Cost-Effective Material Selection: Long-term, GRE tubing offers a more economical alternative to traditional austenitic steel, improving long-term operational efficiency.
Value
Integrity Validation: With over five years of monitoring, Sproule validates GRE as a reliable solution, reducing operational costs while ensuring performance.
Setting Industry Standards: The successful installations at Trias Westland and Nature’s Heat illustrate how composite materials can enhance geothermal well design, setting a precedent for the industry.
Commitment to Innovation: Sproule’s dedication to out-of-the-box solutions fosters safe, sustainable geothermal operations, addressing current challenges while paving the way for a resilient future.
