Off-Site
Facilities Approach Helps PNGTS Become A Reality.
Since the introduction of
natural gas in the northeast in the 1950's, The
New England natural gas market has endured a
shortfall of peak pipeline capacity due to its
distance from major pipeline supply points in the
Gulf of Mexico. Historically this shortfall has
been supplemented with peak shaving capacity of
LNG and LPG facilities. The advent of
deregulation, coupled with clean air regulation,
has created an unprecedented demand for
baseload natural gas that can best be met
with additional pipeline capacity. In response to
this need, the New England energy community has
tried to develop projects that would increase
natural gas supply and capacity in New England
from Canadian markets.
One of the proposed
projects for bringing this gas to market was the Portland
Natural Gas Transmission System (PNGTS).
After spending more than two years obtaining
federal and state regulatory approvals, the
long-awaited development of this new natural gas
pipeline quickly became a reality.
PNGTS is widely viewed as
a win-win situation for the economy and the
environment. It has become an investment in clean
energy infrastructure that was sorely lacking in
northern New England.
The new pipeline is
used to supply a variety of customers throughout
the region. It provides expanded service to gas
utilities in Maine and New Hampshire and, for the
first time, supplies some of the area's largest
paper mills with clean-burning natural gas.
PNGTS will also provide
fuel to some of the proposed new gas-fired power
plants recently announced. In fact, these
electric power projects represent more than $1
billion worth of additional economic investment
in the region and, with their highly efficient
technologies, will help promote competition and
lower the costs of electric power.
The project involved the
construction of 148 miles of 24"
mainline, and 43 miles of 12" lateral
pipeline in Maine. An additional 100+ miles
of 30" pipe on the PNGTS/Maritimes &
Northeast joint pipeline was also constructed.
Once completed the project
would deliver gas from the tie-in point in East
Hereford, Quebec to the existing New England gas
infrastructure at Haverhill, Massachusetts. Along
the pipeline's route new and existing power
plants and paper mills, as well as new and
existing LDC's would be given opportunities for
gas supply never before available.
Project
Approach:
To meet the rigorous
demand schedules, the project used the following
approach:
- Define
the project team
- Establish
the design baseline with preliminary
engineering.
- Procure
long lead items.
- Premanufacture
all top-side facilities.
- Install
facilities in the field.
- Provide
testing, commissioning and training.
- Provide
project data book documentation.
Define
The Project Team:
The PNGTS operating
company was formed early in the process. This
resulted in a hands-on group of experienced gas
people being involved from start to finish of the
project.
Because of their
experience in project management of large
projects, Bechtel Corporation of San Francisco,
California was selected as the prime contractor.
Northstar Industries,
Inc. of Methuen, Massachusetts was
selected as the manufacturer of all top-side
facilities for the new project in order to meet
the seven-month field construction schedule.
Preliminary
Engineering Process Top Side Facilities:
Prior to procurement or
construction of a single facility, a preliminary
engineering report was completed for each
facility. During preliminary engineering, the
framework for the job was established. This was
accomplished by bringing together all interested
parties (prime contractor, pipeline contractor,
operations personnel, end users, regulatory
agencies, etc.) to thoroughly define the design
criteria of the top-side facilities as well as
the construction interface points.
Reporting:
A report was distributed
upon completion of preliminary engineering which
defined the following for each facility:
- Design
Criteria
- Site
Plans
- Geo-technical
Bore-Hole Investigations
- Piping
and Instrumentation Diagrams
(P&ID's)
- Plan
View and elevation view drawings
- Cost
& schedule
- Material
list
- Job
completion deliverables List
Prior to construction of
the facilities, an engineering and construction
plan was developed to ensure a desirable outcome
in a compressed seven month construction period.
Premanufactured
Meter and Regulating Facilities:
A unique design philosophy
was employed in the fabrication of the four
original PNGTS gate stations. A three module,
single building, premanufactured design was
employed to minimize cost by controlling facility
size and time spent on site.
The first module in the
station was considered as the hazardous area
room, and contained all high pressure gas piping.
Prefiltering was accomplished using Peerless
horizontal particulate filters. Measurement was
performed using Equimeter Auto Adjust II turbine
meters, communicating directly with the Bristol
RTU's. A Mercury Mini AT was mounted on the meter
to provide backup measurement.
Preheating was
accomplished using a shell and tube heat
exchanger mounted in the gas room. Two remote
Teledyne Laars water heaters equipped with Taco
pumps, quietly and efficiently circulated hot
water/glycol around a fire wall to the shell and
tube heat exchanger.
A three way valve with
pneumatic temperature controller damped the
glycol/water and controlled outlet gas
temperature.
Pressure regulation was
accomplished using parallel sets of Grove 900
TE's (working monitor and downstream worker
configuration) along with a Becker Super Monitor
(for fire and single incident overpressure
protection) and token relief valve.
All I/O including
pressure, temperature, boiler control, meter
outputs, flow control, gas/fire/smoke detection,
was all wired back to the DAC Module (Data
Acquisition and Control) which housed the RTU's,
UPS and Satellite Communication Systems, all
within a temperature controlled environment.
The entire facilities
were premanufactured entirely off-site by
Northstar in their Methuen, MA manufacturing
facility. This lowered the overall cost of the
job by minimizing time on site by construction
personnel.
Premanufactured
Main Line Valve Control Sites:
Fifteen main line valves
(MLV's) were installed on the PNGTS System, to
allow for local/remote operation of the valves.
Each MLV control building consisted of an 8' x 8'
x 10' monolithic concrete building. Each building
was shipped with two precast concrete grade
beams. This eliminated the need for costly
concrete and iron work at each site, and enabled
field personnel to set foundations and buildings
in under 24-hours at each site.
Each of the stations were
outfitted with the following equipment prior to
being shipped to the site:
- Bristol
3305 RTU
- Lamarche
UPS System w/Johnson TCV battery bank
- AC
breaker panel
- DC
breaker panel
- Remote
CP monitoring equipment
- HVAC
system
- Satellite
communications equipment
- Voice
and backup data telephone equipment
Once installed in the
field the MLV's were used to open and close
valves, sense valve position, sense upstream and
downstream pipeline pressure, and monitor
remotely the pipeline cathodic protection
readings. The building and RTU were designed to
accommodate remote rectifier control for future
expansion.
Premanufactured
Mainline Odorization Facility:
Odorization of the PNGTS
pipeline is accomplished shortly after the
pipeline enters the United States from Quebec,
Canada. To minimize costs, the facility was
located at a main line valve facility.
In addition to all the
equipment installed at the other MLV sites, the
mainline odorization facility was equipped with a
larger building. The building contained a
3,000-gallon ASME-250 odorant storage vessel, and
redundant NJEX-8200 Odorization System used to
accomplish proportional-to-flow odorant
injection.
The doors and penetrations
of the building were raised 12" and the
floor was epoxy sealed to provide 110% secondary
containment of the odorant storage vessel as
required by NFPA 30.
All odorant lines were
welded to eliminate break points and potential
odors. All equipment and piping was installed by
Northstar prior to shipment to the field.
Premanufactured
Launcher/Receiver Facilities:
Four launcher/receiver
facilities were installed on the pipeline to
allow for future internal inspection of the
pipeline using intelligent pig technology. One
was fabricated and installed by Trans Quebec and
Maritime at the completion of their pipeline in
Canada. Three other facilities were installed as
follows:
- Completion
of a 24" line in Portland, ME
- Kickoff
of a 12" lateral in Albany , ME
- Completion
of a 12" lateral in Jay, ME
To minimize field costs,
the barrels were manufactured, tested, and coated
in Northstar's manufacturing facility and then
shipped to the field for tie-in. To further
minimize costs, the launcher/receiver sites were
placed at either main line valve or gate station
facilities, thereby eliminating additional
driveway, fencing, and other associated site
work.
Host
SCADA Facility:
Since PNGTS was an
entirely new pipeline, no existing SCADA center
or control room existed. To minimize personnel
costs, it was determined that an existing gas
control center would be hired to maintain the
PNGTS SCADA System on a 24 hour basis. Providence
Gas Company was chosen as the host control center
for the project. A modular host server system was
developed knowing that one day it might be
removed from its temporary home to a permanent
facility manned by PNGTS personnel.
During preliminary
engineering the Bristol RTU's were selected to
deliver field I/O through Nova Net, Inc.'s
Satellite Network. From Nova Net's hub in
Colorado, data would be routed via a T-1 line to
a server. Bristol Open BSI would control the data
in the server, with Intellutions providing the
HMI Graphical Interface. PNGTS remote network
capability would be added to allow for viewing
the SCADA remotely at various PNGTS operations
facilities in Maine and New Hampshire.
The basic functional SCADA
system was completed by Northstar during the
aggressive seven month construction phase.
Deliverables for networking, and data base
storage continue to be added at this time.
Procurement
and Manufacturing:
Once the preliminary
engineering was completed and approved by all
involved parties, the procurement process was
completed. All materials were shipped to
Northstar's manufacturing facility in Methuen,
MA. Once there all materials were installed in
precast, six sided, monolithic, concrete
buildings.
All facilities were
welded, hydro-tested, painted, wired, tubed,
labeled, tagged, and loop-checked in a controlled
environment in the plant. This process ensured
not only quality control, but eliminated the
costs associated with travel, storage, and
lodging over the traditional, on-site
construction process. Once completed, the
facilities (some weighing more than 95,000 lbs)
were loaded by crane on low-bed trailers and
transported from the manufacturing facility
directly to the field location. Once set in
the field, a facility could be made functional
and ready for operation in less than one day.
Site
Construction:
Since the majority of the
work on the facilities was completed off-site in
Northstar's manufacturing site, a minimal
amount of work was required on-site. The work
on-site consisted of the following:
- Installation
of foundation (precast on smaller
buildings);
- Placement
of precast, premanufactured
buildings;
- Installation
of ground grid, zinc grid, electric
service, phone service, and signal
wire;
- Alignment
and testing of satellite dish
equipment;
- Erection
of fence and gates;
- Finishing
of grade and stone installation;
- Installation
of driveway and protective bollards;
- Check
out of field I/O.
