Featured Research

from universities, journals, and other organizations

Undersea Channels Studied To Aid Oil Recovery

Date:
May 22, 2006
Source:
Massachusetts Institute of Technology
Summary:
Work in an MIT lab may help energy companies withdraw millions of additional barrels of oil from beneath the sea floor. Typically, companies recover only 30 percent to 40 percent of the oil in a given reservoir. Since a single reservoir may contain a billion barrels total, increasing that "recovery efficiency" by even a single percentage point would mean a lot of additional oil.

At MIT's Morphodynamics Laboratory, research scientist James Buttles adjusts the inflow valve of a sediment-laden, gravity-driven current flowing in an experimental channel. Observing how the sediment is deposited in and around the channel is providing new insights into the structure of oil-rich sediment-filled channels found deep under the sea floor.
Credit: Photo : Donna Coveney

Work in an MIT lab may help energy companies withdraw millions of additional barrels of oil from beneath the sea floor.

Typically, companies recover only 30 percent to 40 percent of the oil in a given reservoir. Since a single reservoir may contain a billion barrels total, increasing that "recovery efficiency" by even a single percentage point would mean a lot of additional oil.

Toward that end, Assistant Professor David Mohrig of earth, atmospheric and planetary sciences and Carlos Pirmez, a research geologist from Shell International Exploration and Production Inc., have been examining one type of geological formation of interest to industry -- channels filled with highly permeable and porous sedimentary deposits that extend deep below the sea floor.

These structures form when sediment-laden currents flow off the continental shelf and into channels on the deep-ocean floor, dropping sand, silt and clay as they go. Over many thousands to millions of years, the channels can become filled with porous sandstone covered by impermeable mud -- a perfect trap for oil and gas that seep up from below.

Over the past 20 years, energy companies have withdrawn significant amounts of oil from such buried channels. But they could extract even more if they understood the channels' internal structure.

"If we could understand how they develop, then we would also understand a great deal about what they're composed of -- the distribution of clay, silt, sand and even gravel that they're built out of," Mohrig said. With a better understanding of porosity and permeability within a channel, companies could more accurately determine how much oil is present, where it is located and how quickly it can be withdrawn.

Researchers have been re-creating the formation of submarine channels in Mohrig's Morphodynamics Laboratory using a 5-meter-square sand table.

The experiments have yielded results that the collaborators call "counterintuitive." On a map, the sinuous submarine channels look like meandering surface rivers. However, they exhibit behaviors that are markedly different and -- to us surface-dwellers -- totally unexpected.

The behaviors stem from differences in density. Water in a river is about a thousand times denser than the fluid it flows through -- air. As a result, a flow tends to remain confined to its riverbed, escaping over the banks only rarely. In contrast, the current running through a submarine channel may be only 10 percent denser than the seawater around it. Thus, the current can spill out of its channel more easily and frequently than a river might.

That difference explains several unexpected findings. For example, at times the bottom of the current sloshes almost all the way up the edge of the channel and then back down again. And at bends, the current may go straight, pouring up and over the bank and dropping its sediment outside the channel -- an outcome with important implications for energy companies as they plan to drill.

Because of their close and continuing involvement in the scientific investigation, the Shell researchers are prepared to put the research findings to practical use. "The experiments that David is doing have never really been done before, so we're learning new things about how channels are put together," Pirmez said. "We're getting new ideas, new concepts that may change the way we think about the subsurface."

The result should be improved predictions, reduced uncertainty and more efficient recovery from these oil-rich submarine formations.

This research was supported by Shell International Exploration and Production Inc. through the MIT Department of Earth, Atmospheric and Planetary Sciences.


Story Source:

The above story is based on materials provided by Massachusetts Institute of Technology. Note: Materials may be edited for content and length.


Cite This Page:

Massachusetts Institute of Technology. "Undersea Channels Studied To Aid Oil Recovery." ScienceDaily. ScienceDaily, 22 May 2006. <www.sciencedaily.com/releases/2006/05/060522150425.htm>.
Massachusetts Institute of Technology. (2006, May 22). Undersea Channels Studied To Aid Oil Recovery. ScienceDaily. Retrieved April 23, 2014 from www.sciencedaily.com/releases/2006/05/060522150425.htm
Massachusetts Institute of Technology. "Undersea Channels Studied To Aid Oil Recovery." ScienceDaily. www.sciencedaily.com/releases/2006/05/060522150425.htm (accessed April 23, 2014).

Share This



More Earth & Climate News

Wednesday, April 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

California Drought Is Good News for Gold Prospectors

California Drought Is Good News for Gold Prospectors

AFP (Apr. 22, 2014) — For months California has suffered from a historic drought. The lack of water is worrying for farmers and ranchers, but for gold diggers it’s a stroke of good fortune. With water levels low, normally inaccessible areas are exposed. Duration: 01:57 Video provided by AFP
Powered by NewsLook.com
Raw: MN Lakes Still Frozen Before Fishing Opener

Raw: MN Lakes Still Frozen Before Fishing Opener

AP (Apr. 22, 2014) — With only three weeks until Minnesota's fishing opener, many are wondering if the ice will be gone. Some of the Northland lakes are still covered by up to three feet of ice, causing concern that just like last year, the lakes won't be ready. (April 22) Video provided by AP
Powered by NewsLook.com
Is North Korea Planning Nuclear Test #4?

Is North Korea Planning Nuclear Test #4?

Newsy (Apr. 22, 2014) — South Korean officials say North Korea is preparing to conduct another nuclear test, but is Pyongyang just bluffing this time? Video provided by Newsy
Powered by NewsLook.com
Nasa Gives You An Excuse to Post a Selfie on Earth Day

Nasa Gives You An Excuse to Post a Selfie on Earth Day

TheStreet (Apr. 22, 2014) — NASA is inviting all social media users to take a selfie of themselves alongside nature and to post it to Twitter, Facebook, Flickr, Instagram, or Google Plus with the hashtag #globalselfie. NASA's goal is to crowd-source a collection of snapshots of the earth, ground-up, that will be used to create one "unique mosaic of the Blue Marble." This image will be available to all in May. Since this is probably one of the few times posting a selfie to Twitter won't be embarrassing, we suggest you give it a go for a good cause. Video provided by TheStreet
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins