Within this field of research IFE is working on understanding the behaviour of complex well fluids and develop tools for prediction of their behaviour. The research areas multiphase flow, hydrates, sand, heavy oil and emulsions, wax, scale and corrosion are further described below.
Multiphase pipeline transport cannot be exploited in a safe, controlled way unless the dynamic behaviour of the flow can be predicted with sufficient reliability. This is crucial with respect to early phase feasibility studies, optimal design of pipeline systems, and the safe operation of the transport system. The OLGA family of codes serve the industry with state-of-the-art predictive tools. IFE has developed the basic multiphase flow models in OLGA and current projects at IFE will deliver improved models.
Under certain conditions methane gas and water may react and form an ice-like structure called hydrates. This happens at high pressures and temperatures well above freezing. Hydrates can have dramatic consequences if they form a plug in the pipeline. It is possible to prevent hydrate formation by injecting additives, but this can be a fairly costly solution. An alternative is to let hydrates form, but through various means ensure that it only takes the form of small particles. A mixture of hydrate particles in oil is called hydrate slurry. IFE is working on methods for describing hydrate slurry flow to enable prediction of hydrate particles impact on the production.
Sand is often produced from the near well reservoir zone together with oil and water. The sand is a large problem due to erosion and enhanced corrosion. It may as well form beds in the bottom of horizontal wells and transport pipelines. This may have a negative effect on production. IFE develops models for sand transport in multiphase pipelines.
Heavy oil and emulsions
Large molecules may cause the oil to be very viscous and difficult to transport. Oil with small water droplets mixed in (emulsions) can have a similar effect. Both phenomena are commonplace, and they may make the development of these fields challenging. IFE works on models for pipeline transport of such oils.
Some oils contain wax molecules, and at sufficiently low temperature they will form wax particles. Waxy oils tend to deposit wax on the walls when the fluid is being cooled. Deposited wax on the walls reduces the flow area and reduces the pipeline capacity. The oil can get a gel-like structure at low temperature. Shut down with cool-down and subsequent re-start may become a challenging operation. IFE develops mathematical models to predict the behaviour of such fluids.
Scale is precipitates formed in the production systems during oil and gas recovery. The main and most common scales are inorganic salts like barium sulphate (BaSO4), strontium sulphate (SrSO4), calcium carbonate (CaCO3), but may also be partly organic (naftenates, MEG-based etc.). Sulphate scales are mainly due to mixing of chemically incompatible waters (like sea water and formation water) while carbonate scales are due to pressure release of waters containing high concentrations of bicarbonate.
Scaling may deteriorate permeability in the near-well zone, plug sand screens and production tubings, cause failure in valves, pumps, heat exchangers, and separators as well as and block transportation pipelines.
IFE is engaged in experimental work to determine scaling mechanisms and kinetics. The activity also includes theoretical modelling and development of simulators to predict scaling potential and design scale inhibition programs. A spin-off of this activity is an experimental screening service offered to the industry.
Carbon steel is thermodynamically unstable in water with dissolved CO2 and H2S and the only reason that carbon steel can be used in oil and gas production is that the steel surface becomes covered by a protective layer of corrosion products, oil, mineral scale or inhibitors. It is relatively easy to predict and explain the high corrosion rates on bare steel. The real challenge is to reduce the corrosion and that requires knowledge about the performance of the protective layers, means to predict the breakdown of the layers and methods and techniques to ensure that robust layers form on the surface. IFE runs joint industry projects and bilateral projects for a several international oil companies and chemical suppliers with the objective to find reliable methods and procedures for corrosion control and mitigation.