Eductor vs ejector install#
Eductor vs ejector free#

But, we’ve gone back to basics, getting the same effect, but without the requirements for staff offshore.”Įjectors are also known as eductors, injectors, and surface jet pumps. “A few years ago, if we had a bigger flow, we would have put a compressor out there.

Eductor vs ejector free#

“It is not the most efficient device, but it’s free and it’s efficient enough,” Dawes says. First gas was achieved on 20 September.Īnd, so far, Centrica is happy with the results. The project had been approved in February last year, offshore work started in July, using marine contractor Seajack’s Kraken mobile jackup unit. An animation produced by contractor Amec Foster Wheeler also became a useful tool to show the installation process, from start to finish, through the process. The brownfield work made use of a 3D laser scan on the platform, which was used to create a 3D pipeline model, with particular attention paid to key tie-in spools. In total some 35 spool pieces were installed, as well as a new metering package, at the request of the UK regulator, the Oil and Gas Authority. Then, the 3-tonne eductor package, including nozzle pack, diffuser, and silencers at both ends, on a 17m-long new cantilever structure had to be designed to fit onto a small already busy platform, with pipework for the existing well streams, including Rhyl, also having to be adapted accordingly. Just to make life interesting, at that time, Hysys, a process simulation software, didn’t contain a module for modeling eductors, which meant Centrica had to do the modeling itself. Introducing the eductor involved Centrica’s subsurface team and the process team working closely. This is likely to happen every 2-3 years, Patel says. As part of the design, Centrica will also be able to change out the nozzle on the eductor, relatively easily, as the P-Q relationship changes, to match the new regime. “In this case, we knew the P-Q relationship on Rhyl and North Morecambe,” which meant the eductor was designed fit for purpose, Patel says. not knowing enough about how a new field will perform, or uncertainty around the data, so that flow isn’t what was predicted, so the eductor has not been designed correctly. Patel says in the past the issue has been not enough understanding around the pressure-flow (P-Q) relationship on new fields, i.e. “Eductors have been used elsewhere, but they’ve not necessarily had a 100% record in some applications we’ve used them in,” says Myrtle Dawes, director of projects & decommissioning, Centrica. The North Morecambe wells wouldn’t flow downstream otherwise, so this is helping to produce 8.8 Bcf we wouldn’t realize the value of without the eductor.”Ĭentrica had tried to use an eductor twice previously, but the conditions hadn’t been right. “In the process the pipeline pressure from the North Morecambe wells is increased to 8.5 bar g,” says Ronak Patel, project manager. Using the high pressure Rhyl flow, the North Morecambe well streams can be increased to above the 8.5 bar g downstream pressure, in the process taking out about 9-10 bar g from the Rhyl stream. Rhyl sits at 35 bar g, North Morecambe at 5-6 bar g. The Rhyl field, brought on stream in 2013, via DPPA, needed to have its production pressure reduced for export, so it made an ideal high pressure source for an eductor on DPPA.

Eductor vs ejector install#

Centrica decided to install an eductor, which go by other names, see below - Overlooked and undervalued section) on DPPA.Įductors are relatively simple devices that use a high pressure stream to boost a low pressure stream. The facility producing the North Morecambe field is the North Morecambe or DPPA platform, a 10-well normally unmanned facility, which started production in 1985, and on which it was preferable not to have machinery that would require regular maintenance, such as a compressor.

This meant back pressure was reduced and production from the North Morecambe field would need compression, or some other way to reduce back pressure for it to flow down the export line to the North Morecambe terminal.

The firm had to re-route gas from the giant South Morecambe field, which had been going to its South Morecambe Terminal, where Freon had been used to cool import gas, via a new underground 1.1km, 36in-diameter trunkline to its North Morecambe Terminal, where a new type of coolant is to be used. That was the challenge facing Centrica Energy on its North Morecambe Bay field, in the Irish Sea, off the east coast of England. Not least when external influences – a ban in the use of Freon as a refrigerant – causes you to re-route gas to a different terminal, resulting in an increase in back pressure above which one of your fields will no longer flow. Maintaining production from mature assets will always be an interesting challenge. Elaine Maslin looks at how an eductor has kept a gas field going. Sometimes it’s not all about throwing the latest bells and whistles at a production facility – its best to keep it simple.