AIE performs complete independent assessment of corrosion inhibitors from product selection, through test programme design, management, and technical evaluation, to field testing.
Corrosion inhibition is the reduction or prevention of metallic corrosion using a chemical inhibitor. Chemical optimisation for corrosion inhibition involves finding the most effective and economical chemical inhibitors and the optimal conditions for their use. This can involve testing different inhibitors, varying the concentration of the inhibitor, and adjusting the pH and temperature of the environment. Factors that can influence the effectiveness of corrosion inhibitors include the type of metal, the presence of other chemicals, and the nature of the corrosive environment. There are many different types of corrosion inhibitors, including organic compounds, inorganic compounds, and inhibitor blends. The choice of corrosion inhibitor and the optimisation of its use can help to extend the service life of metal structures and equipment and reduce maintenance costs.
CORROSION INHIBITOR SELECTION PROCESS
The optimum approach to inhibitor selection begins with the design of a suitable test program and the careful selection of a range of inhibitors from qualified chemical vendors. The chemical vendors should be apprised of the field conditions so that as a first pass they can recommend products that have been formulated for similar field conditions, e.g. sour or sweet conditions, high chlorides, high total dissolved solids (TDS) etc.
A fully representative sample should be collected from the system / process under evaluation, so that testing can be performed in actual field fluid. For gas or condensate, an artificially formulated sample would typically be used. Furthermore, the worst-case water conditions should be established so that an effective corrosion inhibitor can be selected after rigorous testing.
Figure 1. Collection of a crude oil sample from an oil well 
Specialist independent third-party laboratories should perform testing of the inhibitors as they have the necessary testing equipment and professional resources needed to perform the testing and provide conclusive results. This will in-turn aid in the elimination of reporting bias.
The whole selection and testing process should be designed and managed by corrosion and chemical management specialists. At AIE, we provide special oversight during the corrosion inhibitor selection process. We evaluate and eliminate problems that can arise at an early stage, and limit the potential of the selection of sub-optimal or inadequate corrosion inhibitors.
CORROSION INHIBITOR PERFORMANCE TESTING
Once a chemical is selected based on an engineered set of performance criteria which validates corrosion control, and other aspects such as flow assurance, compatibility and cost, a robust transition strategy is then employed to ensure the chemical is deployed in a safe and optimum manner.
A robust laboratory testing programme is required to identify inhibitors for service in its respective environment. It must be demonstrated that the inhibitors are effective for the following conditions and criteria:
- To deliver the desired inhibited corrosion rate in the most cost-effective manner.
- Selected corrosion inhibitors must show both physical and functional compatibility with other fluids (existing or proposed) in the system.
- The inhibitors must show sufficient stability under both normal and abnormal/upset process conditions.
- To manage any issues that may arise with maintaining adequate “availability” (i.e., uptimes) for chemical injection in the asset, a key performance criterion is inhibitor persistency.
- The inhibitors do not cause significant detrimental negative impacts or harm to the process. In other words, the inhibitors do not have a significant adverse effect on the efficiency, effectiveness, or outcome of the process.
- The injection locations should be based on a defined study which incorporates all process conditions and factors and considers the most susceptible locations in the system being protected.
CORROSION MANAGEMENT SERVICES
AIE strongly believes that an integrated and systematic approach to corrosion management is fundamental to maintaining asset integrity, reliability, and safety. Our corrosion modelling tools represent the latest development in AIE’s comprehensive corrosion management services.
Veracity CCM is used extensively across a global client base from offshore energy clients to mines in Africa. It supports an holistic and proactive approach to corrosion management that enables operators to manage their threats more effectively and realise the positive impact this has on the economic, environment, health and safety aspects of their business.
The latest functionality of VeracityCCM, the Chemical Optimiser, allows engineers and managers to identify key areas of chemical optimisation at a glance. It does this by blending inputs from multiple sources, such as:
- The in-built corrosion models.
- The historical chemical injection and performance data trended on Veracity CCM.
- Inspection data and real-time probe data.
It then informs the user if the existing chemical injection practices are successful in lowering corrosion rates in their assets. The model also predicts corrosion rates of existing chemical injection practices.
Our Chemical Optimiser tool enhances visibility to the management by revealing the cost impacts of existing practices allowing them to make data-driven decisions.
If you would like to know more about any of AIE’s corrosion management services and Veracity software capabilities and how we may be able to assist you, please contact us at email@example.com