Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Microfluidics probe 'cholesterol' of the oil industry

23.10.2017

Rice University lab's devices clarify how dispersants modify asphaltene to keep pipes open

It sounds cliché, but things do get worse before they get better when oil and gas lines are being cleared of contaminants, according to Rice University researchers. Until now, nobody knew exactly why.


Graduate student Yu-Jiun Lin holds a microfluidic device used to show how and why dispersants are able to break up deposits of asphaltene that hinder the flow of crude oil in wellheads and pipelines.

Credit: Jeff Fitlow/Rice University

Usage Restrictions: For news reporting purposes only.

Asphaltene is a complex of hydrocarbon molecules found in crude oil. It is the source of valuable asphalt and can also be made into waterproofing and roofing materials, corrosion inhibitors and other products, but when it builds up in a pipeline, it's trouble. Asphaltenes are often called the "cholesterol" of the oil industry since they are known to coagulate and slow or even stop the flow of oil and gas in reservoir rock.

Rice engineer Sibani Lisa Biswal and her colleagues used their unique microfluidic devices, instruments that use a small amount of fluid on a microchip to perform a test, to examine four commercial chemical dispersants that curtail the buildup of asphaltene in wells and pipelines. The devices allowed them to watch how the dispersants react with asphaltenes.

The Rice-led study appears in the American Chemical Society journal Energy and Fuels.

Ensuring flow through pipelines is paramount in oil and gas production, so advances that help keep lines clear are important to the industry. To date, chemical companies have generally performed static bulk tests on anti-asphaltene products, Biswal said.

The Rice lab makes microfluidic devices with microscopic channels through which researchers can watch the dynamics of asphaltene deposition in real time, with or without dispersants and at a variety of flow rates.

"Everything in our system is transparent," Biswal said. "Crude oil hasn't been very compatible with the microfluidic devices others are using (because the channels and pillars are too wide), and the type of devices we're making have only been possible with recent materials. We're one of the early groups to push the idea that we can use these systems to visualize oil flow processes

The devices allow oil to flow around pillars that are only 125 microns wide and leave channels that are roughly the size of those in oil-bearing formations. Through a microscope, Biswal and lead author and Rice graduate student Yu-Jiun Lin watched as asphaltene formed delta-shaped clumps in front of and behind the pillars, eventually filling in the channels.

When chemical dispersants were added to the crude, the researchers saw something they didn't expect: The deposits appeared even sooner, but then began to break down and fall away in the flow.

Dispersants are designed to make asphaltene particles smaller, and the experiments proved they do. "The idea is, if you make the crude oil nanoparticles smaller, it's less likely that they're going to be able to deposit inside a pipeline or plug porous media," Biswal said.

"But almost all tests up to now have been done on a bulk scale and very few under flowing conditions. Companies were just seeing if their chemicals make particles smaller. And they do. What they didn't understand is that the smaller the particle is, the less likely it's going to follow the fluid stream. In the presence of dispersants, deposits can actually get worse."

The saving grace, she said, is that dispersants appear to chemically alter asphaltene by increasing repulsion between the aggregates. That makes it more difficult for particles to stick together. "We refer to them as softer asphaltenes," Biswal said. "It doesn't take much force to break up large aggregates."

Lin said dispersant manufacturers typically use liters of crude oil in each test. "We just need a milliliter of crude, and we get better resolution than they do," he said. "When the asphaltene content is very low, traditional methods fail to see a difference in chemicals, or even a deposit."

Co-authors of the paper are postdoctoral researcher Peng He, lecturer Mohammad Tavakkoli and Francisco Vargas, an assistant professor of chemical and biomolecular engineering, all from Rice; Nevin Thunduvila Mathew, Yap Yit Fatt and Afshin Goharzadeh of the Petroleum Institute, Abu Dhabi, United Arab Emirates; and John Chai, a professor of engineering and technology at the University of Huddersfield, United Kingdom. Biswal is an associate professor of chemical and biomolecular engineering and of materials science and nanoengineering.

The Abu Dhabi National Oil Co., the Abu Dhabi Oil research and development subcommittee and the Petroleum Institute supported the research.

###

Read the abstract at http://pubs.acs.org/doi/10.1021/acs.energyfuels.7b01827

Follow Rice News and Media Relations via Twitter @RiceUNews

Video: https://youtu.be/2mah3t_KSew

VIDEO CAPTION: Rice University researchers employ microfluidic devices to show how and why dispersants are able to break up deposits of asphaltene that hinder the flow of crude oil in wellheads and pipelines. In this time-lapse video, at top, as crude oil without dispersant flows through a device, deposits build up on the front and back of microscopic pillars. At bottom, with dispersant added, softened asphaltenes build up on the pillars and are then broken up by the flowing oil. (Credit: Biswal Lab/Rice University)

Related materials:

Asphaltene analysis takes a giant step: http://news.rice.edu/2015/02/23/asphaltene-analysis-takes-a-giant-step-2/

Biswal Lab: http://www.ruf.rice.edu/~biswalab/Biswal_Research_Group/Welcome.html

Vargas Research Laboratory: http://www.vargaslab.org

Rice Department of Chemical and Biomolecular Engineering: https://chbe.rice.edu

Rice Department of Materials Science and NanoEngineering: https://msne.rice.edu

Located on a 300-acre forested campus in Houston, Rice University is consistently ranked among the nation's top 20 universities by U.S. News & World Report. Rice has highly respected schools of Architecture, Business, Continuing Studies, Engineering, Humanities, Music, Natural Sciences and Social Sciences and is home to the Baker Institute for Public Policy. With 3,879 undergraduates and 2,861 graduate students, Rice's undergraduate student-to-faculty ratio is 6-to-1. Its residential college system builds close-knit communities and lifelong friendships, just one reason why Rice is ranked No. 1 for quality of life and for lots of race/class interaction and No. 2 for happiest students by the Princeton Review. Rice is also rated as a best value among private universities by Kiplinger's Personal Finance. To read "What they're saying about Rice," go to http://tinyurl.com/RiceUniversityoverview.

Media Contact

David Ruth
david@rice.edu
713-348-6327

 @RiceUNews

http://news.rice.edu 

David Ruth | EurekAlert!

More articles from Life Sciences:

nachricht One step closer to reality
20.04.2018 | Max-Planck-Institut für Entwicklungsbiologie

nachricht The dark side of cichlid fish: from cannibal to caregiver
20.04.2018 | Veterinärmedizinische Universität Wien

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Spider silk key to new bone-fixing composite

University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

Im Focus: Basel researchers succeed in cultivating cartilage from stem cells

Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.

Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...

Im Focus: Like a wedge in a hinge

Researchers lay groundwork to tailor drugs for new targets in cancer therapy

In the fight against cancer, scientists are developing new drugs to hit tumor cells at so far unused weak points. Such a “sore spot” is the protein complex...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

Magnetic nano-imaging on a table top

20.04.2018 | Physics and Astronomy

Start of work for the world's largest electric truck

20.04.2018 | Interdisciplinary Research

Atoms may hum a tune from grand cosmic symphony

20.04.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>