According to Bolonkin (2008), pipelines are, in general, the most economical way to transport large amounts of oil or natural gas over land. Compared to railways, this modal has a lower cost per unit and greater capacity. In addition, it works 24/7, except during maintenance. Interruptions that may affect the transportation period, such as weather or traffic, do not affect pipeline operation.

However, a significant disadvantage of using this type of transport is the possibility of leaks that may occur as a result of erosion, corrosion, landslides, acts of vandalism, actions of third parties, among others. Due to the high pressure at which the products are pumped and, depending on the type of substance transported, these leaks can cause serious environmental and socioeconomic damage.

With this in mind, oil and gas transportation companies are continually looking for more sensitive, accurate, repeatable, reliable and robust leak detection systems (SDVs). The American standard API 1149 defines these characteristics as follows:

• Sensitivity: the smallest loss that can be detected (with confidence)
• Accuracy: The accuracy at which the size and location of the leak can be estimated
• Reliability: the confidence that can be attached to any reported loss
• Availability/Robustness: The uptime that can be expected from the SDV under normal conditions; and also the resilience of the SDV to unexpected conditions

There are several technologies for leak detection that have different advantages, disadvantages and levels of complexity. The API 1130 standard classifies these technologies into two types:

• External systems, which depend on specific hardware, instrumentation or sensors to operate, such as optical fiber, acoustic emission detectors, etc.;
• Internal systems, which use existing infrastructure, such as mass or energy balance, RTTM (Real Time Transient Model), statistical analysis, etc.

One system that currently protects more than 11,000 miles of pipeline around the world is the Synergi Pipeline Simulator (SPS), which combines Statefinder and Leakfinder modules. These modules are based on the represented states (variable conditions) of a pipeline system.

For the system to perform as expected, it is necessary to create a hydraulic model of the pipeline, provide real-time measurement data from SCADA, and also provide consistent fluid property data. Thus, through the field data and the fundamental laws of fluid mechanics, the model will track conditions very close to the real pipeline and investigate temporal anomalies between the measured data and the model.

One mechanism that the SPS uses to reconcile differences between measured and modeled head losses are diagnostic flows, which are flows injected or removed from the model to preserve the mass balance when there is a discrepancy. If average diagnostic flows exceed a predefined dynamic threshold, the software will:

• Alarm;
• Define the type of abnormality;
• Define the confidence level of the alarm.

There are 5 alarm statuses: (1) Starting (in case detection has been turned off), (2) Okay (there is no abnormality), (3) Circulation (indicates circulation has occurred), (4) Injection (indicates flow injection) and (5) Leak (indicates leakage). Statuses 3 and 4 normally indicate modeling or instrumentation problems, as they are very unusual events to occur in an operating pipeline.

It is important to note that, as stated in Annex A of API 1130, no CPM (Computational Pipeline Monitoring) methodology or technology is applicable to all pipelines, because each system has an exclusive configuration and operation. Furthermore, detection limits are difficult to quantify due to the unique characteristics presented by each pipeline. Boundaries must be determined and validated, system by system, and perhaps section by section. Pipeline operating conditions (steady state or transient) will influence the minimum size of product loss that can be detected so detection limits for CPMs are not fixed. During transients the detection limits are higher.

Another factor that must be highlighted is that efficiency objectives (sensitivity, accuracy, repeatability, reliability, availability and robustness) are often at odds with each other. For example, high sensitivity in leak detection generally leads to more false alarms and, consequently, lower reliability, so it is essential that tuning is carried out and monitored according to the main relevant points defined by the customer.

With the addition of the communication driver for the AccuLoad IV, AutoLoad® offers its customers the possibility of integrating eight preset models from different manufacturers. In addition to AccuLoad IV, we have AccuLoad III, AccuLoad III.net and MicroLoad from TechnipFMC, Fusion4 MSC-L from Honeywell, Danload-6000 and DL-8000 from Emerson and TCC from Unidata.

In addition to electronic flow predeterminers, AutoLoad® has communication drivers for various field devices such as road scales, access control units, electronic panels, PLCs (Programmable Logic Controllers), URVs (Vapor Recovery Units) and odorization, in addition to interfacing with telemetry systems for tanks and motorized valves, firefighting systems and the main corporate systems on the market.

“Automind's positioning is that of a company that provides Integrated Automation Technology Solutions, on a turnkey basis, consisting of services, software and equipment, covering the stages of conception, implementation and maintenance. For the logistics segment, we offer our TMS (Terminal Management System), AutoLoad®. We constantly seek to update AutoLoad®, including new features demanded by the market and the integration of new control devices for terminals, mainly electronic flow predeterminers, providing our customers with flexibility in choosing equipment to control their process”, commented the Director of Business at Automind, Adriano Macário.

AutoLoad® is installed or in the process of being installed in more than 50 terminals in Latin America.

The implementation of the new System was divided into two stages, a stage called pilot and another stage of replication. The first step aimed to ensure that the specified and implemented functionalities would meet the expected performance requirements for the project. With the approval of the first stage, the project would move on to the second, with the replication of the System to the other Bases.

The implemented system, equipped with complementary technologies, allows the terminal's fuel handling operations to be carried out automatically. A hardware and software architecture supported by a cluster of servers in a virtualized 100% environment and redundant Programmable Logic Controllers guarantee the high availability of the System.

Based on the Terminal Management product, Autoload®, the following were integrated: the loading platform equipment, the tank telemetry systems and motorized valves, the uninterrupted power system, the steam recovery unit, the of pumps and the MDriver corporate system.

In the pilot stage, lasting a year and a half, the first base to receive the System was BADUC, a Duque de Caxias base located in the state of Rio de Janeiro. In view of the results obtained, after fulfilling the performance requirements for the System, Petrobras Distribuidora promptly approved the completion of the second phase of the project, when replication to the other bases began.

During the replication of the System, in addition to the already expected performance requirements, other efficiency indicators stood out, such as the reduction in the cost of electricity with the implementation and use of the intelligent module for controlling the pump yard.