Computer models. Virtual reality. Four-D
seismic. They're easy! They're fun!
And too often in this high-tech world it's easy for
geologists to become so immersed in the newest technology that they
forget that their journey ultimately begins and ends with the rocks.
Some say this inexorable move to a digital world
has endangered the most basic type of research available to geologists:
the thousands of feet of core from wells all over the globe.
It wasn't that long ago when industry officials were
fearful that massive amounts of core were being dumped.
But today, largely through the efforts of various
geological organizations, the need to preserve cores and samples
is beginning to catch on, and companies throughout the United States
are looking for ways to make a growing body of core available to
the profession as a whole.
"A lot of people have been working very hard on the
issue of core preservation," said Edith Allison, program manager
with the Department of Energy's office of natural gas and petroleum
technology and chairperson of the AAPG Committee for Preservation
of Core and Samples.
We are making progress in getting the message out
to the industry," she said, "and today we are beginning to reap
the rewards of this effort."
AAPG's committee has been instrumental in the efforts
to encourage permanent preservation of cores and samples — as well
as informing geologists just how to access the material.
"As earth scientists we now have a wide variety of
tools and processes to carry out our investigations," says the mission
statement for the AAPG Committee. "Ultimately, however, we need
the data recorded in the rocks to support the emerging automated
programs for interpretation and analysis."
For AAPG members there is a particular need for representative
samples from the subsurface, but these rocks are expensive to collect,
difficult to archive and their existence may not be obvious to those
who need them the most.
Cores and cuttings don't lose their usefulness over
time — in fact, the opposite is true.
They often have characteristics and potential data
values that can't be duplicated today.
A Concerted Effort
A new study on preservation of geoscience data and
collections conducted by the National Research Council is expected
to be released in April, Allison said.
The study was commissioned by several groups, including
AAPG, DOE, the U.S. Geological Survey and the American Geological
Institute, and it examines the issues associated with access to
and preservation of geoscience data.
Its overall goal is to develop a comprehensive strategy
for managing geoscience data in the United States.
AGI, in conjunction with the DOE and the private
sector, also has established the National Geoscience Data Repository
System to promote geoscience data preservation, and increase its
accessibility to the geoscience community.
A key element of the NGDRS is GeoTrek, a geographic
information, Internet-based catalog that now encompasses 72 percent
of all core currently available in the lower 48 states.
Data added to the GeoTrek system in the past six
months include:
- The USGS Core and Cuttings library in Denver's database.
- Unocal's onshore publicly accessible cores and cuttings.
- The Texas Railroad Commission log data.
- Chevron's core data continues to be added.
Future additions planned over the next nine months
include the Kansas core metadata and a link to the Texas Bureau
of Economic Geology live inventory control system that tracks ancillary
data and provides real-time core location information.
"Just a few months ago the coverage offered by GeoTrek
was much smaller, so the system has made important strides recently,"
Allison said. "Anyone who has not been to GeoTrek in a while needs
to return, because it is a much better product today."
With GeoTech a person can search by location and
find all the core available on an area — and in many cases link
directly to the Internet system of the appropriate repository.
"And it's free," Allison added. "This service has
been operational for a couple of years and is a tremendous resource
for making the core and samples useful to the industry.
"That's a critical part of what AAPG's committee,
AGI and other organizations are doing today," she said, "focusing
on making the core and sample data useful to working geologists."
Kansas' Example
Individual repositories also are working to make
their core and sample libraries more accessible to working geologists.
In Kansas, for example, the Kansas Geological Survey
has cataloged its entire core repository on its Web site.
"You can go to our Web site and find all the core
we have, so you can find out anything about any well in the state
— all 300,000 of them," said Tim Carr, director of petroleum research
for the Kansas Geological Survey.
The system is flexible and can be searched by section,
township, range or by well name.
"We have taken the initiative to make our core accessible
to increase its value," Carr continued. "Not many states are undertaking
this type of project, and we are currently working to expand even
further the value of the core by linking all our databases together."
Which means that now when you go to the Web site
to search for a specific core, the program will also upload any
logs, geologic tops or data analysis that might be available on
that well.
"It's not just the preservation of the core that's
important," Carr said. "All those rocks are meaningless if all they
do is sit in some warehouse and gather dust. The data isn't valuable
by itself — we have to make it valuable by making it accessible
and meaningful."
In a state like Kansas much of the oil and gas activity
centers on small independent firms working to milk the last bit
of oil out of reservoirs, he said, and they need all the data they
can get to design reservoir stimulation projects or design new fracs.
"Often core is the only historical data available
on older fields," Carr said. "Logs may not have been good quality
if they were even taken, so a piece of core in the middle of a field
can be a valuable commodity.
"For example, we are working on a proposal for a
fracture stimulation in a field discovered in 1942," he said. "There
is very little information like logs on the field, but we do have
six cores from those early wells. Those rocks will be very important
in designing the fracture stimulation program and ultimately enhancing
production from an old field."
More Work Remains
The AAPG Core and Sample Preservation Committee recently
reviewed AAPG BULLETIN articles for 1979-1981 and 1990-1993, and
discovered that about 40 percent of the authors relied on cores
and samples as the principle source of data for their research.
"Even with advances in data analysis and manipulation,
this reliance on rocks is expected to continue," the committee said.
The committee is doing its part to promote the usefulness
of core preservation, including its strong support for the core
poster session that was held at the AAPG annual meeting last year
in Denver, in which about eight people presented a poster on their
research and had the core available for examination.
"This poster session was designed to help more geologists
understand that core is still a very valuable resource," Allison
said. "The program was successful and attracted many convention
goers, so we are planning to organize a similar session at the 2003
Salt Lake City annual meeting."
Unfortunately, financial constraints too often prevent
state or regional repositories from making the core more accessible.
Texas has been extremely successful in its efforts to preserve important
core collections, but, according to George Bush with the Texas Bureau
of Economic Geology, "Without funding we are unable to take advantage
of new technologies that could increase the use of the data."
Texas is the premier example in the United States
for preserving core and samples. Today the state's two repositories
hold 614,000 boxes of core and 540,000 boxes of cuttings. Two major
oil companies have contributed large core collections in the last
10 years:
- In 1994 Shell donated 2.2 million linear feet of core and cuttings
from 29 states to the state repository along with its warehouse
and a $1.3 million endowment to maintain the core.
- Last year Texas received 85,000 boxes of core from BP-Amoco.
Today additional funding is the critical issue for
Texas' state repositories in Austin and Midland.
"Due to the lack of funding, we have not been able
to enter the Shell cuttings data into our database," Bush said.
"Although the cuttings are available to the public, their utility
is greatly diminished by the fact that they are not in the database.
We also have not completed our barcode project in either facility."
While there is a great deal of work that still needs
to be done to make the core accessible and useful to working geologists,
officials are overall pleased with the heightened awareness of preserving
core.
"For example, the Kentucky and Ohio geological surveys have both
built new core repositories in the last year or so, and that's significant
at a time when many states are running out of room and have no funds
to add additional space," Allison said. "Plus, some oil companies
like Unocal and Chevron are retaining possession of their core libraries,
but are making large quantities of that core available to the public.
"A couple of years ago many of us in the geological community
were fearful that much of this core resource would be lost," she
continued. "The message today is that we in fact did not lose a
great deal of core. The states and companies realized the danger
and made arrangements to preserve much of this resource.
"It hasn't been easy and there is still a great deal of work to
do, but we have made significant progress," she continued.
"However, now that so much core has been preserved, it's our responsibility
to find ways to make it useful because when it stops being data
and just becomes stuff, that's a different kind of loss."