OVERVIEW
This report discusses
the feasibility of treating brine from oil and gas
operations to make it usable for beneficial
purposes. A separate section on unconventional oil
and gas operations discusses the increased demand for
water resources and the need for recovery of fresh
water and re-use of brine byproducts from this
activity. The study was conducted by the Department of
Petroleum Engineering and the Texas Water Resources
Institute at Texas A&M University, College Station Texas
and CH2M Hill Company.
Motivation
for the Research
Texas has long been one
of the top petroleum producing states in the nation. As
fields have matured, more brine water is produced along
with the petroleum resource. More brine water is being
re-injected as well, to sustain production, prevent
subsidence, and to dispose of excess produced brine.
Texas has long been struggling with a lack of water
resources and as the population of the state grows, more
demand is being placed upon surface and ground water
sources of fresh water. As these issues become more
important, more attention is turning to recovery of
fresh water from these brine byproducts of O&G activity.
Unfortunately produced
brine can not be used without treatment to remove
harmful substances. Untreated produced brine has
contaminants that make it unpalatable for humans or
livestock. Re-injection of the brine back into the
formation from where it was produced has been the least
expensive; hence preferred disposal method for brines.
Other issues include:
(1)
Desalination of wastewater such as oil field
brine can be expensive.
(2)
Oil and gas companies are not water providers.
(3)
Less expensive surface and ground water has
provided adequate supplies of fresh water for
communities, livestock and agriculture interests.
Most of these issues
are the result of the characteristics of oil field
brine. Large quantities of produced water are brought to
the surface in Texas as a result of various natural
resource extraction activities. The composition of this
produced fluid is dependent on whether crude oil or
natural gas is being produced and generally includes a
mixture of either liquid or gaseous hydrocarbons,
produced water, dissolved or suspended solids, produced
solids such as sand or silt, and injected fluids and
additives that may have been placed in the formation as
a result of exploration and production activities.
The Texas Water
Development Board is seeking to determine whether
desalination of produced brine offers promise as a
source of fresh water resources. Research is currently
underway at a number of companies to assess the economic
and technological feasibility of desalting this product
water to develop water of sufficient quality to meet
certain local water supply needs and to allow
consideration of disposal options other than well
injection. At Texas A&M University, a team of scientists
and engineers is working on this concept and is working
to further the technology and put it into commercial
practice.
Specific research needs
are harder to prioritize. For the past three years A&M
has worked to find technologies to employ in
desalination and to outline ways to establish a value
for the resource that is recovered by this treatment.
The research has found that the technology is available
to desalinate certain brines produced in petroleum
operations [1]. However that technology needs to be
improved, the value of fresh water and local water
supply needs must be established, and the environmental
and regulatory issues associated with beneficial use
must be addressed.
Recommendations
for the Advancement of Desalination Technology
Our feasibility study
recommends a number of steps to help advance
desalination technology. Technology demonstrations or
“road shows” could bring new concepts of pure water to
communities in need. The TWDB should continue to lead by
example and should encourage other State Agencies to
address water needs in a comprehensive fashion and to
communicate, remove paperwork barriers, and advance
worthy projects.
Collaboration should
not be limited to just Texas organizations. The Rio
Grande Basin Initiative is one example of economic
development programs that seeks new approaches to
solving problems [44] common to the states of New Mexico
and to Texas. A research alliance has been established
that includes these two states plus Arizona named
CHIWAWA (Consortium for Hi-Technology Investigations in
Water and Wastewater) [45]. The purpose of this
initiative is to create sustainable urban and rural
water supplies and protect environmental quality by
conducting innovative, collaborative research, education
and training programs in inland desalination technology,
concentrate disposal and water resources management. A
consortium including New Mexico State University, The
Texas A&M University System, and the University of Texas
at El Paso and two water utilities, the Cities of El
Paso and Alamogordo are pooling advanced expertise and
experience in arid environment water resource management
to address pressing technological, management and
training issues related to inland desalination, source
water characterization and concentrate and water
resources management.
Finally the efforts to
address the needs of local communities at the local
level is paramount especially in the regions of the
State where fresh water resources are insufficient for
current or future needs. This report on the new
technology of desalination and re-use of oil field brine
is only a part of the effort necessary to develop
commercial programs. There must be efforts by all to
communicate to the users. This involvement with the
community is expected to make any proposed projects more
likely to be accepted and thus support our efforts to
create these new water resources more effectively.
