ALFAsim Hydrates: Simulation of hydrates formation, transport and agglomeration

 

Client: Galp | Partner: ESSS

 

Hydrate formation in oil and gas wells and production lines can be adressed by using two different modelling approaches: Classic and Population Balance. The first, more simplified and commonly used, considers the instantaneous formation of hydrate particles, which have fixed sizes and do not have the ability to agglomerate. 

In this project the focus is the development of models for hydrate formation considering free gas and increasing GORs, models for deposition of hydrate particles on the walls of pipes and models considering free aqueous phase and increasing water cuts, using a population balance, an innovative and modern approach that treats the nucleation, growth, breakage and agglomeration of hydrate particles separately and calculates their effective diameters. This allows the simulation of formation, transport, agglomeration and hydrate deposition for any production scenario, whether oil, gas or water dominated, from low to high GORs and WCs. Furthermore, the explicit modelling of these phenomena makes it feasible the representation of the effects of low-dosage hydrate inhibitors (both kinetic inhibitors and anti-agglomerants), besides the classical thermodynamic inhibitors (MEG, ethanol, among others).

Given the complexity of the phenomenon of hydrate formation, it is also intended to address the problem through 3D modeling and simulation, with coupling between fluid dynamics (CFD) and particulate (DEM) simulation in different conditions and geometries. This type of coupled simulation can bring valuable information and help to increase the understanding of the transport and dynamics of hydrate dispersions in pipelines and assist in the investigation of possible stable dispersions and adequate velocities to prevent deposition in multiphase flows. Finally, the information obtained through these simulations should help in the development of one-dimensional models, which is the final objective of the project.

These new models will be implemented as a plug-in of the ALFAsim software, a one-dimensional (1D) platform for simulating multiphase flows that intends to support decisions in the design phase, as well as being able to be used in online monitoring systems as a real-time prediction tool in the most diverse scenarios that may be encountered. 

The project is financed by ANP’s investment clause in research, development and technological innovation, in a partnership between ESSS, ISDB and Petrogal Brazil.