MODERNIZATION OF THE TALARA REFINERY (PERU)
In order to improve the production pattern towards higher-value products, and increase the level of conversion and capacity to process heavy crude oil and even promote self-sufficiency of electricity, PetroPerú decided to modernize the Talara Refinery, installing new process units, services and complementary facilities.
The successful bidder for the works was the Cobra SCL UA & TC Consortium and Cobra Peru, granting the Peruvian company Graña y Montero S.A., now CUMBRA, the project packages related to the execution of the three submarine pipelines: two SWI inmissaries for water collection and a SWO outfall for discharge, which they subsequently subcontracted to the company Europea de Hincas Remote Directions S.A. (EUROHINCA) together with the associated maritime works.
During September 2019 and June 2021, Eurohinca executed, in addition to the tunnels, the dredging works, rescue of tunnel boring machines and anchoring of special pieces associated with the maritime works, providing the maritime means (dredger, boats and auxiliary vessels) and specialized personnel (supervisory staff and divers) necessary for their execution. It also had its own hydrography equipment with state-of-the-art probes.
In this project, Eurohinca provided the necessary Construction Engineering for all the contracted works, supplied and supervised the construction of the HDPE pipes of the outfall and the immissaries, and manufactured, with its own means and specialized personnel, the reinforced concrete pipes necessary for the piling, with the highest quality and under the strictest regulatory standards. in order to guarantee the execution of the microtunnels, subjected to pressures of up to 3 bars.
Finally, Eurohinca carried out the dredging of Pier 2 for liquid cargo of the port of the Talara Refinery contracted directly by the Cobra SCL UA & TC Consortium and Cobra Peru S.A.
The COVID-19 pandemic severely affected the execution of the works, causing considerable delays, although the work did not stop at any time despite the extreme situation experienced, thus demonstrating the high degree of commitment of the Eurohinca staff.
WHAT?
Manufacture, supply, assembly and construction of the Emirates and Outfall, including the required maritime works and construction engineering for the Talara Refinery Modernization Project (Peru).
WHO?
Client
Petróleos del Perú S.A. PETROPERÚ
Main Contractor
Consortium Cobra SCL UA & TC and Cobra Peru S.A; GyM, SA
Microtunneling Contractor
Eurohinca (Europea de hincas teledirigidas S.A.U.)
WHEN?
Construction took place between September 2019 and June 2021, and commissioning took place in December 2021.
WHERE?
Talara, Peru.
Image 1: Talara Refinery location.
WHY?
The main objectives of the Talara Refinery Modernization Project (PMRT) were, on the one hand, to reduce the sulfur content of diesel, gasoline and LPG fuels, to a maximum of 50 ppm and, on the other hand, to increase the profitability and competitiveness of the refinery by increasing the crude oil processing capacity from 65,000 to 95,000 barrels per day (BPD). processing heavy crudes and converting waste products from process units to marketable products.
Image 2: Talara Refinery (Peru).
To carry out the different industrial processes associated with oil refining, desalinated water from the desalination plant located in the refinery facilities is used. The desalination plant is supplied with seawater through two catchment lines (immissaries). Subsequently, both the rejection of the desalination lines and the industrial waters from the processes are evacuated through the submarine outfall.
Image 3: General view of SWI-A', SWI-B' (immissaries) and SWO (outfall).
HOW?
The main works carried out by Eurohinca in relation to the contract with Graña y Montero (GyM) at the Talara Refinery, in addition to the construction engineering, were the following:
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Manufacture of reinforced concrete pipes for jacking. Specifically:
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Standard DN2000 pipe (L=3 m). 189 units
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DN2000 intermediate station set. 6 units
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Standard DN2400 pipe (L=3 m). 240 units
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DN2400 intermediate station set. 8 pcs.
Image 4: Manufacture of reinforced concrete pipes for jacking in Piura (Peru).
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HDPE pipe supply and manufacturing supervision:
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HDPE DN2400 SDR 26 pipe (53 m) electrofusion welded for the diffuser.
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HDPE DN2400 pipe (15 m). Including telescopic piece for the microtunnel-diffuser connection.
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HDPE DN1800 SDR 26 pipe (15 m). 2 pcs. Including telescopic piece for microtunnel-intake tower connection.
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HDPE DN1800 feedthroughs (3 m). 2 pcs. Connection pieces embedded in the intake tower for connection to the microtunnel.
Image 5: HDPE pipes for intake and diffuser sections.
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Execution of microtunnels:
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SWI-A Immissary'.
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SWI-B Immissary'.
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SWO Outfall.
Image 6: General view of SWI-A', SWI-B' (immissaries) and SWO (outfall).
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Maritime works associated with microtunnels:
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Dredging of the seabed.
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Diving work for the rescue of tunnel boring machines.
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Adaptation of the seabed.
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Anchoring of diffuser section and special pieces.
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Connection with microtunnel.
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Preparation of the foundation platform.
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Anchoring of intake towers.
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Connections with microtunnels.
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Carrying out bathymetric work and analysis of information in the office.
As shown in the layout of the immisors, both pipelines run in parallel, with their lengths being 298.70 m for the SWI-A' immissary and 313.03 m for the SWI-B' immisory.
Image 7: SWI-A' and SWI-B' immisory layout.
In section, both microtunnels start at an altitude of -5.31 m with a negative slope of -3.06% in a straight section, then followed by a curve with a radius of 700 m and about 34 m in length and then another straight section of -8% slope that connects with a curved section of 650 m radius, ending the tunnel in a straight section with a zero slope at an altitude of -23.50 m.
Image 8: SWI-A' and SWI-B' Immissions Section.
The attack well of the immisaries was executed taking advantage of the intake and pumping pitch of the desalination plant located next to the coastline. The thrust walls were built insulated at a distance from the entrance joints that allowed a double thrust system to be installed to optimize the execution of the excavation by simultaneously installing up to three reinforced concrete pipes for each of the immissaries. As the thrust walls were isolated and not supported at the back by the ground, their dimensions were of an unusual width to be able to resist the thrust forces of the driving itself and prevent overturning during excavation.
Image 9: Launching shaft for SWI-A' and SWI-B'. Double jacking frame.
Image 10: Isolated thrust walls. SWI-A' and SWI-B' Immissaries.
The reinforced concrete jacking pipe used for both immisers had an inner diameter of 2,000 mm and an outer diameter of 2,500 mm with a pipe length of 3 m. The pipes were designed and manufactured by Eurohinca at a plant located in Piura, about 120 km from the site.
Geologically, the ground that was planned to be crossed in the execution of SWI was predominantly rocky, formed by shales and sandstones. With the information available, a rock cutting wheel was installed, however, during the excavation the ground behaved in a very plastic way, seriously hindering progress in the first tunnel executed (SWI-B'). For the second tunnel, SWI-A', the design of the cutting wheel and the dosage of drilling fluids were revised, considerably improving performance.
SWI-B's start date was November 5, 2019, ending on January 6, 2020. As for the SWI-A', work began on January 19, 2020, and began on February 13, 2020.
In the case of the SWO outfall, it was a tunnel of 748.50 m in length, starting at an altitude of -3.80 m and ending at an altitude of -16.10 m. Both in plan and section, the tunnel layout was completely straight with a negative slope of -3.50%, as can be seen in the following image:
Image 11: Seaoutfall SWO section.
The tunnel lining was made up of reinforced concrete piling pipe with an inner diameter of 2,400 mm and an outer diameter of 3,000 mm with a pipe length of 3 m, designed and manufactured by Eurohinca.
The geology was mainly composed of sands and some short stretch with gravel and there were no unforeseen events or changes with respect to the information provided by the available geological-geotechnical study.
Image 12: General view of the SWO outfall working platform and shaft.
The start date of the excavation of the SWO outfall was February 23, 2020, but a few days later the State of Emergency was declared in Peru due to the outbreak of the Covid-19 pandemic, causing the paralysis of the tunnel work for a few days and a minimum progress for a long period of time slowed down by the closure of the pipe factory. Obeying government regulations for the prevention of Covid-19. It should be noted that between infections and direct contacts.
Finally, after months of effort in the midst of the pandemic, the SWO outfall tunnel was completed on June 18, 2020.
After the execution of each of the immisaries and the outfall, the dredging work of the arrival area of the TBMs was carried out. In the case of the immediary, the dredging was carried out in rock (shale and sandstone) which, together with the maritime conditions of the area during these works, meant that the daily progress of material extraction was minimal and discontinuous. In the case of the SWO outfall, as the land is mainly made up of sand, the dredging rate of the area adjoins.
Image 13: Rock dredging of the SWI immissaries.
Image 14: Sand dredging of the SWO outfall.
After carrying out the dredging work, the TBMs were recovered through the operations of installation of the rescue beam, hooking and disconnection of the TBM-tunnel carried out by a team of expert divers, hoisting and transfer to port of the TBMs.
Image 15: TBM recovery after completion of SWI-B'.
Subsequently, the intake towers were installed in the inmissaries and the diffuser section in the outfall.
Image 16: Launch top piece SWI Intake Tower
Imagen 17: Transporte tramo difusor a punto de fondeo
Image 18: Anchoring of the diffuser section
Rodrigo Moldes Bodelon
TUNNEL TECHNICAL DATA
Length
1.200 m
Inner diameter
2.000 mm
Outter diameter
2.500 mm
Slope
Descending 2% at the input and ascending from 2% at the exit
Geology
High plasticity clays, silts, organic material and sands
Starting Level
-8.5 m (awl)
Starting Level
-8.5 m (awl)
Starting Level
-8.5 m (awl)
Starting Level
-8.5 m (awl)
Starting Level
-8.5 m (awl)
BIBLIOGRAPHY
Sea outfall executed by jacking pipe for the location of gas pipeline (Altamira, Mexico). Journal of Public Works (ROP 3624), October 2020.
https://www.tcenergia.com/activos/sistema-sur-de-texas-tuxpan/
https://trenchlesstechnology.com/2020-project-of-the-year-new-installation-runner-up/
https://www.napipelines.com/building-big-microtunneling-terratest-world-record-project/