Skip to main content
European Commission logo print header
Zawartość zarchiwizowana w dniu 2022-12-27

IMPROVEMENT AND TESTING ON GAS WELL OF A FIRE FIGHTING DEVICE : BIL FIRE PREVENTER

Cel

The objective of this project is to improve a water injection system (SPOOL) fitted on a gas well to extinguish a fire after an accidental eruption on a drilling platform. This process has been developed by BERTIN and is fully successful for fire without structure above the gas well.
But the presence of a platform induces impingement and separation of the gas water mixture. Under these conditions it is not possible to extinguish fire with the current configuration of the injection system, although the temperature of the structure and the radiation of the flame are considerably reduced.
In order to improve the device, the study proposed to add two crowns, aimed at delivering fine automatized water inside the radial flow which run out under the platform floor. It is important to notice that when atomization is only achieved in the well, it remains very few droplets after the impingment on the platform floor. In a first time, the trials were achieved on a low scale model, which was mainly composed of a smooth steel plate as the platform floor; extinction has been obtained for a water/gas flow rate ratio closed to 7. These trials on a low scale put forward that the position of the crown under the floor was a very sensitive parameter.
In a second time, the floor was fitted with representative beams, as the stiffeners of a real platform floor. The floor of the model is still horizontal but it looks like an irregular plate. Extinction succeeded but for a water/gas flowrate ratio of 15, in the best cases.
The trials of the "BOSS, composed of the spool mounted on the gaswell and the twin crowns fixed under the platform, have been carried out on a GAZ de FRANCE site in CHEMERY in October 1990 1st to 5th. In order to provide a fine water atomization, each part of the BOSS was fed with a high pressure pump. Some trials were devoted to dry chemical powder tests, and some other ones showed the limited efficiency of fire hose nozzles despite their large flowrate. However, extinction has never been achieved on gas leaks from 10000 to 40000 m3/h.
Because of the complexity of the structure, it appears impossible to insure the extinction of a fire in such conditions.
The position of water atomizers is to be carefully chosen, especially for the wall flow, due to its strong influence on the efficiency.
The BOSS device, in its state of development is however able to ensure :
- a radiation abatement from 80 to 95 percent, in a stable way.,
- keeping on the temperature of the structure at a level under 100 deg. C.
The part of the general aim which is to save the structures can be reached, and close intervention of skilled firemen become easier.
The evolution of the device closely depends on operating conditions. For instance, the applying scope for the BOSS should be improved if some modifications could be done on the platform.
The following recommendations should be followed in order to reach more efficiency :
- in case of a blow-out, it is necessary to remove the rotating table and all the equipment staying above the well, so that a free jet leak can be found again, that it is possible to extinguish with a limited amount of water. During this operation, the BOSS is used to reduce radiation around the leak, to keep the structure safe, and to allow a close intervention.
- it is necessary to avoid the obstacles which work as flameholders. The floor should be as flat as possible, without variations, avoiding IPN type beams, and prefering cylindrical profiles. In these conditions, the crowns should be more efficient.
The project, with a total duration of two years, is divided into 4 main phases :
PHASE 1 : SIZING AND LABORATORY TESTS
The first step of this work program consists of the analysis of the behaviour of the droplets in a gas flow with impingement on a plate and deviation by various obstacles : trajectory and vaporization
.
This study must lead to the determination of the water mass flowrate and the drop size distribution required to obtain a sufficient water vapour concentration anywhere under the platform in order to reach the lower limit of inflammability of the gas.
The adequate atomizers will be tested on a specific test bench. Then, preliminary tests with a cold gas will be carried out to qualify the water and gas flows.
Finally, some extinguished tests will validate the results of the analysis.
PHASE 2 : DESIGN AND FABRICATION OF AN EXPERIMENTAL SPOOL Design,sizing, construction drawings, procurement and fabrication of the new water injection SPOOL equiped with the new atomizers defined during the Phase 1.
PHASE 3 : TESTS ON SITE
Tests in real configurations will be carried out on a GAZ DE FRANCE facility in CHEMERY, near BLOIS in France, with natural gas extracted from underground storages.
The operating conditions will be :
- using a INTRAFOR drilling platform
- gas flowrate : between 15. 000 and 50. 000 m3/h
- water flowrate : up to 150 to 200 m3/h
The tests will involve :
- injection and ignition of the gas
- stabilization of the flame and gas flowrate at a given value
- increase of the water flowrate up to the extinguishment of the flame
- tests of re-ignition and stop
The test will be analyzed with the measurement of :
- gas and water flowrates
- radiation fluxes around the platform
- temperature of the structure
PHASE 4 : SYNTHESIS AND DETERMINATION OF THE INDUSTRIAL SPOOL - ANALYSIS OF THE EXPERIMENTAL RESULTS
Inquiries to the potential users in the gas and petroleum industries to determine their needs, and so, a range of industrial spools.
Evaluation of the market.
Final report.

Zaproszenie do składania wniosków

Data not available

Koordynator

BERTIN & COMPAGNIE
Wkład UE
Brak danych
Adres
RUE PIERRE CURIE 59 ZI DES GATINES B.P. 3
78373 PLAISIR
Francja

Zobacz na mapie

Koszt całkowity
Brak danych