The Return of Kinetic Hydrate Inhibitors

Kinetic hydrate inhibitors (KHIs) have been serving the petroleum industry for many years. They are normally used at dose rates of <3% of the produced water, resulting in considerable savings in CAPEX/OPEX. However, several uncertainties and challenges have prevented their more widespread usage, including a lack of Consistent test protocols, poor repeatability of test results, concerns over performance under shut-in conditions, the potential risk of hydrate formation at the top of the pipelines, and relatively low cloud points/fouling issues, which can cause problems in produced water handling/reinjection (PWRI) and/or monoethylene glycol (MEG) regeneration schemes. In this communication, we present the latest developments related to KHIs, including the results of a testing technique based on crystal growth inhibition that produces reliable and repeatable results, performance under shut-in conditions, risk of hydrates at the top of pipelines, and a technique for removing KHIs from produced water prior to PWRI or MEG regeneration. We also demonstrate that it is possible to predict the potential, suitability of KHI-based solutions for any specific field application prior to even starting the experimental Campaign and/or designing a KHI + THI combination (where THI denotes thermodynamic hydrate inhibitor). Results show that MEG is an excellent synergist for the KHIS investigated, and 1% KHI can replace large quantities of MEG. Considering the fact that many: of the operational challenges and uncertainties associated with KHIs have recently been addressed and that there are excellent opportunities for combining KHIs With MEG, we expect resurgence in KHIs as a reliable and economical option for preventing gas hydrate problems. This could have significant economic and environmental impact, as well as extend the life of petroleum reservoirs.