The creation of oil emulsions due
to mechanical strength and natural
surfactants during production is undesirable. The challenges associated
with transporting and refining oil have led researchers to probe into
practical demulsification methods. An in-depth understanding of crude
oil rheology and operating conditions to treat emulsion is necessary.
The main objective of the current study was to investigate the rheological
behavior and demulsification rate of crude oil emulsions. The rheological
behavior of a crude oil emulsion was studied by manipulating its temperature
(30 °C–90 °C), shear rate (0.1–1000 s–1), and water volume fraction (20%, 30%, and 40%).
For emulsions of various water content, the rheological studies followed
the non-Newtonian shear thinning behavior, which was explained effectively
by the Herschel–Bulkley model. Experimental results also indicated
that the measured viscosity of emulsion decreased significantly with
temperature, while increasing water volume fraction increased viscosity.
The rates of demulsification of water in crude oil emulsion in direct
current fields were investigated under various conditions by using
an electrochemical cell. The separation rate of water increased along
with the applied field, water content, and salt concentration. Results
of this study indicated that emulsion separation was governed by the
magnitude of the applied electric field as well as the type of electrode.
TX 75083-3836, U.S.A., fax 01-972-952-9435.
AbstractIt is essential that precipitation of "asphaltenes" is recognised early in the planning stage of any EOR project so that appropriate testing can be performed to evaluate whether there will be a negative impact on reservoir performance. This paper presents detailed evaluations of extended compositional and PVT data which were obtained during extensive EOR tests using a light Middle East crude and CO 2 . The compositional measurements clearly confirm that "asphaltene" precipitation occurs during gas injection and that the properties of the heavy end fraction are significantly reduced.Before the C36+ data could be successfully interpreted, it had to be "calibrated" with data from a true boiling point distillation; this is explained. Detailed evaluations of the C36+ concentrations in the normalised C11+ fraction during swelling, equilibrium contact and forward multiple contact tests are presented.The changes in the C36+ concentrations result in changes in the physical properties of the plus fraction. It is essential that these changes are reflected in the fluid characterisation and tuning of the EOS. Also included are detailed predictions from various EOS models with and without taking into account the alteration in the physical properties of the C+ fraction.Because minimal tuning is performed, predictions from the EOS models should be reasonably precise. The paper includes preliminary predictions of EOR behaviour using different injection gas compositions.The paper concludes with recommendations for modifications to analytical programs for investigating gas injection processes which would lead to a better understanding of the fluid behaviour. Also included are suggestions for future research to better characterise the deposited "asphaltenes" which will hopefully result in more accurate predictions as to whether these precipitated asphaltenes will negatively impact reservoir performance.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.