Using pigs in mining: Overcoming challenges—4Pipe Hidropig

By - Eng. João Henrique M. Sousa

4Pipe Hidropig has established itself as one of the leading Brazilian companies specializing in pipeline cleaning and inspection services using pigging technology. Headquartered in Pindamonhangaba/SP and operating nationwide, the company has stood out for its technical approach, customized solutions and constant investment in innovation and training.

With a comprehensive portfolio that includes operations in oil pipelines, gas pipelines, mineral pipelines and industrial lines, 4Pipe combines technical knowledge, field experience and state-of-the-art equipment to ensure the integrity and operational efficiency of critical assets. The company employs everything from foam and mandrel pigs to advanced instrumented pig technologies, in compliance with the most rigorous national and international standards. 4Pipe's philosophy is centered on operational excellence, safety and sustainability, with a focus on delivering accurate and reliable results to its customers. Whether in industrial, urban or remote and difficult-to-access environments, the company operates with agility and strategic intelligence, joining forces with global partners to offer complete and high-performance solutions in the pipeline sector.

4Pipe Hidropig's Performance

In yet another important operation in the pipeline transport sector, 4Pipe Hidropig carried out the cleaning and internal inspection of two terrestrial pipelines that transport ore slurry, built in API5L Carbon Steel - Gr.B Sch40, both with a nominal diameter of 10" and an approximate length of 6 km each, assets located in the region of the state of Pará, close to the Amazon rainforest. The operation consisted of executing a sequence of cleaning pigs (foam and mandrel) and subsequent inspection using state-of-the-art ultrasonic technology, in line with current technical standards such as ASME B31.4, ASME B31.8, API 1163, and NACE and IBP guidelines.

Context and Logistics: Amazon Region Challenges

The assets were located in a difficult-to-access area, which imposed a series of logistical challenges, especially with regard to the mobilization of equipment, pigs, instrumentation, and the technical team.

The distance from our operational base, located in Pindamonhangaba/SP, required meticulous planning and the adoption of customized solutions to guarantee the integrity of the equipment during transportation, as well as the efficiency of execution in the field. Furthermore, typical climate conditions of the Amazon region, such as heavy rains and restricted access, required flexibility and adaptability from the team throughout the project.

Cleaning pigs: Preparing the Pipeline

The passage of cleaning pigs is a mandatory operational practice for preserving the internal condition of pipelines. When applied periodically, it prevents the accumulation of deposits and liquid phases, preventing the occurrence of localized corrosive processes. It is during the cleaning process that some specific problems of each pipeline become evident, such as deposition of organic material, inorganic incrustations, corrosion residues and even geometric anomalies.

In this success story, the cleaning sequence was conducted using foam pigs of different densities for initial sediment removal, followed by mandrel-type pigs with discs and brushes for more aggressive unclogging and removal of mineral incrustations and rust residues.

The mandrel pig was designed for different applications, allowing for the rapid replacement of its components, and can therefore be used in cleaning, removal, separation and calibration services.

The metal body has different configurations, and can receive seal discs, guide discs, cups, steel brushes, polypropylene brushes, calibrating plates, magnetic belts, transmitter housing, among other accessories. It was designed to prepare the line for the passage of the inspection pig and also for cleaning and draining the products, since its seal discs and cup allow the sealing of the entire pipeline, the brushes to scrape off the debris accumulated inside the lines, the magnetic belt to absorb ferrous residues and the calibrating plate to check the internal geometry of the pipeline.

For this project and to achieve greater effectiveness in the process, specific pigs were developed, with greater cleaning power and efficiency, without excessive aggression to the assets, preserving their integrity and safety. This was the key tool for us to achieve success in this operation.

This process was essential to ensure the ideal condition of the line for the passage of the instrumented pig, optimizing the quality of the data collected and reducing the risk of blockages or damage to the inspection equipment.

Benefits of Cleaning Operation: Increase Operational Efficiency and Flow Gain

The cleaning operation in mineral pipelines using pigs represents a consolidated and highly effective practice in maintaining the integrity and performance of the mineral slurry transportation system. In the specific case of a 10-inch mineral pipeline, the regular passage of cleaning pigs promotes the removal of incrustations, sediments and solid deposits that naturally accumulate over time on the internal walls of the pipeline.

This process results in a significant reduction in internal friction, restoring the effective diameter of the pipeline and, consequently, promoting a significant gain in flow rate. Field studies and operational analyses show that, after performing efficient cleaning with PIGs, it is possible to observe increases in flow rate of around 5% to 15%, depending on the initial degree of obstruction. This gain directly impacts the productivity of the system, reduces energy consumption associated with pumping and increases the useful life of the equipment, contributing to a more sustainable and economically advantageous operation.

In addition to the improvement in hydraulic performance, cleaning with PIGs also allows for better monitoring of the pipeline condition, facilitating inspections and preventing serious operational failures. Thus, preventive maintenance through pigging is consolidated as an essential strategy in the efficient management of pipelines.

In this case, for example, we obtained a gain of almost 2.5x the initial flow of the system, from 180 m³/h to 400 m³/ h.

The benefits of cleaning with pigs in the pipeline directly impact the pumping system, in a positive way, such as:

• Reduction of Mechanical Effort on Pumps With less flow resistance, pumps operate with less effort to maintain the same flow rate, which reduces mechanical and thermal wear on components such as rotors, seals and bearings.
• Decrease in Energy Consumption Reducing pressure drop means less pressure is needed by the pumps, which results in lower power demand and, consequently, energy savings. This is especially relevant in continuous operations, where energy costs represent a significant portion of the operating cost.
• Increased Equipment Lifespan Operating under optimized conditions reduces the frequency of failures and the need for corrective maintenance. This extends the service life of pumping sets, reduces unscheduled downtime and improves system reliability.

These combined gains reinforce the importance of a well-planned cleaning routine with pigs, not only to maintain pipeline capacity, but also to ensure good performance and durability of the pumping system as a whole.

Inspection with Ultrasonic Pig

The asset inspection was carried out using ultrasound-instrumented (UT) pigs. This equipment is capable of detecting, with high resolution, thickness losses, localized corrosion and other internal and external anomalies along the pipeline. The following were evaluated:

• Loss of metal mass;
• Creep (lumps, swelling, ovalization);
• Localized and general corrosion;

Lessons learned and added value

This operation highlighted the importance of robust planning and synergy between national and international companies for executing projects in remote regions. Joint action allowed operational obstacles to be overcome, such as mobilization by river and air, and highly complex technical work to be carried out safely and within the established deadline.

Among the lessons learned, the following stand out: The importance of prior validation of the internal geometry of the pipeline for the appropriate selection of cleaning pigs;Innovation and engineering and project solutions, in addition to the use of cutting-edge tools and technologies; The need for a detailed plan for mobilizations and activities in remote areas; Efficient interaction between teams, especially in projects with multiple stakeholders.

The added value stands out not only for the good results obtained in this campaign, but also for the promotion of research and innovation in the sector, in order to make operations even more viable and efficient. The impact for the client was the conservation and management of assets, in addition to the contribution to increased productivity, reverberating in an increase in results, goals and profit.

The cleaning and inspection of these pipelines consolidates another technical milestone for 4Pipe Hidropig, reaffirming the company’s commitment to operational excellence, safety and technical compliance. The partnerships throughout this project demonstrate the strength of collaboration in favor of asset integrity and innovation in the pipeline sector.