2nd November 2020 – Landivisiau microtunnel

Boring a 530 metre-long, 2.15 metre-wide microtunnel in one of the hardest and most abrasive rocks calls for the highest levels of vigilance. Add to that a 26-metre height difference between the entry and exit points as well as crossing both a river and the busy Paris – Brest railway lines.
The extreme complexity of the gas pipe project in Brittany called for expert advice and hands-on assistance both prior to and during microtunnelling operations. Contracted by SADE TS, OPTIMUM engineers reworked the geotechnical aspects of the project to ensure complete alignment with geological conditions onsite. Daily monitoring of the boring operations allowed for progress rates to be maintained and safeguarded against technical risks such as tunnel narrowing, fluid dispersion or excessive wear on the cutting tools.
The microtunnel is now complete, excellent teamwork throughout.

22nd October 2020 - Black Sea landfall

OPTIMUM continues to expand its international reach with its latest mission in Romania. The 1500m long horizontal curve landfall project, which used an anchored lay barge during pull-back, will connect two natural gas fields 120kms out in the Black Sea to the inland gas treatment plant .
OPTIMUM’s engineers were present in Romania for over 6 weeks and supervised HDD operations onsite 24/7 given the geotechnical complexities of the project, now one of the longest landfalls ever drilled in soft soils (sand, silt and clay).
OPTIMUM has been involved in this project since 2018 at the request of the contractor, Black Sea Oil & Gas, providing technical expertise to support the engineering and project preparation teams.

8th October 2020 - From study to drilling completion

  • Echirolles : a 65 metre-long urban pipe ramming project under the Grenoble ring road
  • Brioude : a 140 metre-long HDD crossing to bypass new motorway construction
  • Albias : 3 parallel 310 metre-long HDD crossings under the rural Aveyron river

Three projects, all in complex geotechnical and / or geological environments, in which OPTIMUM teams accompanied their clients from the very beginning to the very end of their trenchless projects. These recently completed, diverse gas pipeline projects all highlight the significant advantages in having OPTIMUM’s specialist engineers at the contracting authority’s side to analyse, develop and monitor trenchless projects from their inception (feasibility studies) through to works completion (onsite drilling supervision). A perfect understanding of the project history as well as all relevant geotechnical constraints allow for decisions to be taken quickly and for technical advice and monitoring to be more pertinent, minimizing risks and optimising operations.
Three technical challenges, three projects successes.

7th September 2020 – Réseaux VRD

Understand the full scope of a project and propose relevant solutions at every step of the way ; theexhaustive article published in the latest edition of Réseaux VRD underlines the intelligence of OPTIMUM’s involvement in the Dordogne river crossing.

22nd July 2020 - 250 projects and counting !

In just 30 months, OPTIMUM has conceived over 250 trenchless projects, examining and supervising 51 000 linear metres of crossings as well as 15 km of landfalls. Its growing team of specialist engineers reinforces the pertinence of each assignment by optimising operations, cutting drilling costs and timeframes, minimising geotechnical risks and simplifying bore paths.
Despite the current climate, OPTIMUM continues to support its customers on trenchless jobsites throughout France, and beyond, further consolidating its position as THE trenchless engineering expert in the French market. Here’s to the next 250 !

22th June 2020 - BRL : Aqua Domitia project

The second DN560 pipeline allowing the BRL - Aqua Domitia project to cross the River Thongue is now installed.This double 170 metre HDD crossing was drilled by Coquart & Fils, who commissioned OPTIMUM to provide geotechnical monitoring (G3 mission). As such, the engineers provided expertise at every stage to optimise the drilling process :

  • During site preparation : geotechnical dossier analysis and definition of a programme of additional investigations to finalise engineering plans
  • During drilling of the first pilot hole : deepening the HDD profile following observation of a geological deviation causing drilling fluid losses
  • During boring : optimization of the boring sequence

Effective teamwork, based on mutual trust, once again led to a great result.

18th June 2020 – Technical emergency, OPTIMUM solution

BIR, on behalf of Orange, has successfully pulled a DN500 HDPE tube containing 15 fibre optic lines. The technical urgency of the project arose at the end of January 2020 as the need to divert a sensitive network installed in a precarious dam became apparent.
OPTIMUM mobilized teams to deliver a complete engineering study, from determining the bore path to supervising the geotechnical surveys and sizing the final tunnelling works, all in a record 4 months and during the Coronavirus crisis.
Despite the urban location and the considerable environmental challenges, the team completed this fully curved, 185-metre-long HDD crossing, on time and on budget.

12th May 2020 – France / UK interconnection

As part of RTE’s French-UK interconnection project, the dual trenchless crossing in Frénouville is now finished. Both of the 140 metre-long, 10 metre-deep HDD crossings, passing under one of Normandy's busiest rail routes, required precision control at every stage.
OPTIMUM assigned specialist engineers from the document validation phase through to works completion, ensuring round the clock monitoring on site, day and night.
Finalised in April 2020, the project was not only completed on time and in compliance with strict SNCF requirements, but also whilst preserving the health and safety of the dedicated engineers who worked despite the Covid-19 pandemic.

5th February 2020 – Rail crossing in Normandy

Drilling 20m below the busiest railway in Normandy calls for the highest levels of vigilance and expertise. By accompanying RTE’s trenchless project in Harfleur on a daily basis and assisting drilling operations around the clock, OPTIMUM ensured the railway network was preserved throughout.

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The crossing is now complete; a great challenge, successfully met.

20th December 2019 – G3 Missions

Contracting authorities are increasingly aware of the importance of geotechnical issues in trenchless projects, leading to an more G3 Missions.
As such, OPTIMUM is expanding its offer to assist drilling contractors in controlling geotechnical risks and identifying possible deviations during drilling operations. Its most recent G3 contract will contribute to the extension of the hydraulic network in the Languedoc, south-west France in early 2020.

5th November 2019 – 30th SNCF railway crossing

This week OPTIMUM will finalize its 30th railway crossing project. These must not only integrate a “classic” trenchless study but also adhere to the strict SNCF criteria necessary for drilling authorization. They enable the complexity and the multiple risks inherent in working under railway lines to be managed proactively and effectively.
Subsequently, OPTIMUM is also able to monitor and control the drilling operations, in line with the SNCF stipulation that this be delegated by the contracting authority to an independent, specialist project manager.

11th Oct 2019 – Dual pipeline crossing at Cubzac

The dual gas pipeline crossing of the Dordogne at Cubzac is complete. By reworking the project engineering and assisting technical operations on a daily basis, OPTIMUM managed to halve both the drilling costs and the project timeframe.
We are proud to have been able to support Coquart & Fils in this great achievement, now its longest ever directional drilling project (2x850m). Great teamwork

3rd Oct 2019 – Ovale & Sens sponsorship

Sponsorship choices speak volumes about a company’s ethics. As the Rugby World Cup continues in Japan, OPTIMUM is delighted to announce its sponsorship of Ovale & Sens, a rugby club near Paris open to teenagers and adults, men and women alike, with mental health issues.
Runners up in the French adapted rugby championship in 2017-2018 and winner of the Ile-de-France shield during the 2018-2019 season, the team never ceases to amaze us. Bravo !

17th August 2019 – Landfall expertise expands overseas

OPTIMUM broadens its international scope with an AMO contract in Portugal. The landfall project, with over 600 m of horizontal directional drilling (HDD), will link an offshore wind farm to the Portuguese coast.
This mission further highlights OPTIMUM's landfall expertise after other missions in France, Italy, Romania and the Reunion Island.

Comment prévoir les résurgences

19th June 2019 – OPTIMUM at VST 2019

How to predict the resurgence of drilling fluids ?
François Gandard discusses the issue at the "HDD Forum" at the VST trade fair in Chatou, France from 18 - 19 June 2019.

6th June 2019 – Ingénierie Territoriale

The trenchless technology focus dossier in this month’s edition of Ingénierie Territoriale reinforces the relevance of these techniques in today’s congested environment Good preparation is the key to success.
OPTIMUM’s analytical method is detailed at the front of the dossier.