PITTSBURGH, PA - In a project
funded by the U.S. Department of Energy's National
Energy Technology Laboratory (NETL), researchers are
conducting important geologic tests to determine how oil
wells in the oceans can be stabilized while drilling in
slabs of salt thousands of feet thick. Initial results
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The $3-million, four-year project
supports the President's National Energy Policy, which
calls for increasing domestic energy supplies through
development of advanced technologies. At stake is the
economic development of the fuel reserves below the vast
1,000-mile-wide seas of the Gulf of Mexico, which many
developers believe is the United States' last major
source of petroleum outside the Alaska wilderness.
"The President's National Energy Policy cites 21st
century technology as the key to environmental
protection and new energy production, and it
specifically highlights deep water drilling technology
for oil and gas," said Mike Smith, Assistant Secretary
for Fossil Energy. "Projects such as this can increase
our Nation's energy security while reducing costs to oil
producers and protecting the environment."
The Gulf of Mexico is located at the southeastern corner
of the United States, and is flanked by the United
States to the north, Mexico to the south, and Cuba to
the southeast. This enormous body of water is nearly 800
miles from north to south, and more than 2 miles deep in
some sections. Beneath these waters lie estimated
reserves of 28 billion barrels of oil. By comparison,
the mainland United States had 32 billion barrels of
proven reserves in 2002.
The Gulf is dotted with thousands of oil and gas rigs,
but only recently has production begun in the deepwater
portions of the Gulf. By 2005, as much as 67 percent of
daily oil production and 26 percent of daily gas
production in the Gulf will come from deepwater fields.
According to Purna Halder, a geophysicist at NETL, the
underwater topography and geologic structure of the
region make it a difficult and expensive place to drill.
Unlike traditional underground patterns found when
boring land-based wells, the formations underlying the
Gulf are not as well understood by those seeking to
recover the treasure trove of oil.
"Huge formations of salt - thousands of feet thick in
places - underlie the Gulf," said Halder. "Oil and gas
are found thousands of feet below the salt in
traditional sand formations. The way this salt is
distorted by pressures and movements is of keen interest
to those who do the exploration." The process by which
the salt is stressed is called deformation.
"Even without the oddities of salt, these wells are
engineering marvels," said Jerry Casteel, who manages
the project for NETL. "Some are 20,000 feet under the
surface, slicing through thousands of feet of salt and
into sedimentary rock, after penetrating 8,000 feet of
water. The cost of drilling a well can run upwards of
$100 million, and any collapse or severe damage can deal
an enormous blow to domestic production."
As part of the joint government-industry project,
researchers at Sandia National Laboratories in
Albuquerque, N.M., are using sophisticated computer
models to help industry determine stable locations where
drilling can take place through or near salt formations.
The project's two major thrusts are predicting stresses
under the surface in and adjacent to salt formations to
ensure stability during drilling, and determining what
load the well casings can carry to ensure the well's
viability during its production lifetime. The research
provides essential guidance to optimize well
trajectories and casing designs to ensure economical
production from sub-salt and near-salt reservoirs.
The improved insight that has resulted from the work so
far has been applied in two of the five largest oil
fields in the Gulf: the Thunder Horse North and Mad Dog
fields operated by London-based BP, along with multiple
partners. The more aggressive well casing design
implemented in the Thunder Horse North field resulted in
well construction cost reductions of more than $30
million, according to BP's estimates.
"Working with [the Department of Energy and this
research team] on salt mobility, we have identified ways
of positively impacting the project economics and
delivering a more reliable solution ?this epitomizes the
manner in which government agencies and industry can
collaborate to produce extraordinary results," said
Bernard Looney of BP.
The research results are being applied to other deep
reservoirs in the Gulf, and research is ongoing.
In addition to NETL, Sandia, and BP, project partners
include Australia-based BHP Billiton Ltd., ChevronTexaco
Corp. of San Ramon, Calif.; ConocoPhillips Co. of
Houston, Texas; ExxonMobil Corp. of Irving, Texas;
Halliburton Co. of Houston, Texas; Kerr-McGee Corp. of
Oklahoma City, Okla.; and Netherlands-based Royal
Dutch/Shell Group subsidiary Shell International
Exploration and Production Inc.