There are many naturally occurring substances within hydrocarbon systems that can
hinder the transport of fluids from reservoir to final destination. Flow assurance
programs encompass multiple disciplines and tests designed to identify and mitigate
these obstacles and ensure economic and uninterrupted flow of hydrocarbons. Solids
such as asphaltenes, waxes, hydrates and inorganic scale, can all cause blockages
and transportation problems. Early detection is essential to a productive reservoir.
The flocculation and deposition of asphaltenes in the reservoir, wellbore and surface
facilities is a major concern to oil companies as it may reduce oil production as
well as result in increased downtime and costs for remedial treatment. An understanding
of the conditions at which asphaltenes will flocculate can help Oil Companies operate
their reservoir and facilities more effectively. Asphaltene flocculation can be
caused by ...
Core Lab's equipment allows for a variety of imaging experiments including isothermal
depressurization experiments, titration experiments, particle size distributions
and solids onset determinations. Visual as well as Near-Infrared (NIR) detection
systems add to the accuracy of onset determination.
Stock tank oil determination of wax appearance temperature (WAT) and wax dissolution
temperature can be determined through the use of cross polar microscopy (CPM) or
Differential Scanning Calorimeter (DSC). Live fluid WAT can be determined using
Near-Infrared (NIR) system or PFI equipment. High temperature gas chromatography
is used to identify the paraffin distribution in a reservoir fluid, which together
with the WAT, is used to tune deposition models.
Hydrates are the crystalline cage-like hydrogen bonded solid lattice of water containing
trapped molecules of hydrocarbon gas. Hydrates are important in the oil and natural
gas industries because many processes involve treating streams where water and hydrocarbons
are in contact. If the conditions of temperature and pressure are right, a stable
hydrate phase may form. These hydrates can block pipe and other process equipment,
reducing operational life, cutting revenue and represent a serious safety hazard.
Inorganic scale results from chemical reactions induced by thermodynamic changes,
fluid mixing or corrosion. Inorganic scale can be crystalline or amorphous depending
on the source. Almost all scale requires the presence of water to form. Inorganic
scale forms when the ionic balance of the host water is disturbed. Changes to water
chemistry are usually the result of changing P&T conditions, blending incompatible
waters or corrosion (interaction with metals).
Geochemical software is available that can predict the thermodynamic onset conditions
for scale based on water chemistry or blended water compositions. These predictions
depend largely on the solubility values calculated from ionic concentrations in
the water and often ignore the change in chemistry from flashing the solution gas.
In practical application, laboratory tests are recommended to refine and prove the