Cradle Arc Share Discussion Threads

[david77] 16/12/2014 19:47

Google "Shell Prelude gas platform" - that's why gas is cheap

[broshm] 16/12/2014 18:29

Thans Doc but as I see it , the falls vastly outnumber the rises .

[the_doctor] 16/12/2014 16:25

presumably because it's illiquid, so if some dope wants to sell, the share price will drop

it does also work the other way with buys though of course :o)

[broshm] 16/12/2014 16:15

These aim shares are a disgrace , why the drop on this turnover ?

[the_doctor] 15/12/2014 10:05

FSE, hence I said 'more efficient'

However, I questioned it since I wasn't sure how material the pressures were in the wider context. Furthermore, I considered it likely there were other factors too.... and as per the document I posted a link to, there are.

[fse] 14/12/2014 23:14

Nice contract win for the subs.
I still have a few of these down in ye auld vaults ...
Had to have a larf at the doctor for this one..

ItchyCrack 1 Dec'14 - 11:31 - 28399 of 28430 0 0
Why does a DGC need to be down the well? Why can't it be near the top?

the_doctor 1 Dec'14 - 11:41 - 28400 of 28430 0 0
More efficient?
Not 100% sure

FSE> the doc..... after all of these years posting on here one would almost have thought you grasped the very first piece of this technology. Its like learning the ABC and you starting with B.
A hint for you its all about blowing or sucking and the old limitations of lifting above 1 atmosphere...... gosh maybe goatherd will sort you out,

[paulgo] 11/12/2014 16:44

Nothing like covering all eventualities then eh doc?

[the_doctor] 11/12/2014 11:04

I'm guessing the year end update will probably come next week

... but could be after of course, or could be tomorrow.
If they're waiting each day in the hope of squeezing in a bit more info, then it'll be longer. If they have all they anticipate, then perhaps sooner.
:o)

[arf dysg] 10/12/2014 09:10

the_doctor, just for you:

[the_doctor] 10/12/2014 08:59

re 28425, don't get too close to the methane with whatever it is you're smoking!

[arf dysg] 10/12/2014 08:49

hxxp://www.sciencedaily.com/releases/2014/12/141209120400.htm


Princeton University researchers have uncovered a previously unknown, and possibly substantial, source of the greenhouse gas methane to Earth's atmosphere.
[...]
a sample of abandoned oil and natural gas wells in northwestern Pennsylvania [...] many of the old wells leaked substantial quantities of methane.

[arf dysg] 09/12/2014 14:11

supernumerary (28421) "I presume this is the Melanie Rigby in question:"


I think you'll find she's quite famous. For example:

Melanie Rigby,
Pulls up the gas in the well when the pressure is gone...

[the_doctor] 09/12/2014 13:50

I think we're due a year-end update?

[paulgo] 09/12/2014 13:45

Not huge volumes just lately but any buys that have been coming in are fairly chunky, 80k, 90k, 100k+

Good news on the horizon I suspect.

[the_doctor] 08/12/2014 09:55

It was after the DGC trial, seemingly. Would that not date it more recently?

[supernumerary] 06/12/2014 11:43

I presume this is the Melanie Rigby in question:

---------------

Mechanical Engineer
Independent
September 2014 – Present (4 months) Oxford, United Kingdom

Director, Engineering & Technology
Corac Energy Technologies
November 2013 – September 2014 (11 months) Slough, United Kingdom

Managing Director
Corac Energy Technologies
July 2012 – October 2013 (1 year 4 months) Slough

Principal Engineer
Corac Group plc
January 2012 – July 2012 (7 months) Slough, United Kingdom

----------------

Interesting career progression. Sadly her time at Corac ended in September 2014. I wonder if that also marked the end of the DGC programme? I think we should be told.

[timmbo] 06/12/2014 05:44

??? When was this writeup dated?

[bullster] 06/12/2014 02:03

Link showing a picture of the preparations underway at the Hilcorp gas well in Texas, to deploy the DGC.





Corac cites successful field trials in Texas

BY IAN CAMERON

Corac is developing its downhole compressor to function much like an electric submersible pump. Field trials of the downhole compressor were conducted in Texas.



Many gas wells cease production due to liquid loading, but a technology development program is successfully making progress to combat the problem and extend their working lives.

The extraction of gas from wells often declines as the pressure within the reservoir falls. As the pressure drops, the wells begin to load with liquid and methods to remove water are required to maintain gas flow.

U.K.-based Corac Energy Technologies (CET) is developing applications that it says enhance performance in oil and gas production. It is working with several partners to develop innovative, compact turbocompressors.

Demonstrating that the technology has captured the interest of oil and gas majors, CET recently signed agreements with Tullow Oil and BP to develop the applications.

CET’s compressors have proven themselves in industrial applications in Europe and the Far East, logging more than 20,000 hours of maintenance-free operation. The company’s intellectual property portfolio includes more than 40 patents plus several pending and eight European design registrations.

According to the company, the goal of the downhole compressor development program sector was to apply the “unique technical characteristics” of the CET compressors to the oil and gas sector. It said the compact, lightweight and frictionless qualities of its equipment can provide long maintenance-free operating cycles in an application with high value product. It added that the intent “was to produce an equivalent of the ubiquitous electric submersible pump (ESP), so common in oil production, as an artificial lift solution.”

The company’s downhole gas compressor (DGC) development program is exploring technology to position a compact compressor underground in a declining gas well to extend production life.

Other development projects are in progress to define compact compression applications at the wellhead, both on land and on offshore on production platforms.

“Various responses are available for declining fields, yet liquid loaded wells are difficult for conventional compression systems,” said Melanie Rigby, CET’s managing director. “Existing technologies also require significant ongoing maintenance and do not necessarily give the benefits expected.

“The DGC is a compact high-speed turbocompressor running on contactless gas bearings, using production gas as both a bearing fluid and a coolant. The development program aims to demonstrate a system with only one moving part per compression stage that is highly efficient and requires no routine maintenance over a production life greater than two years.

“Downhole gas compression can extend the life cycle of declining wells and improve gas well production. Use of our patented core technologies allows us to design a compact and intelligent compression solution that sits within a seven-inch pipe several thousands of meters below the earth’s surface.”

Corac said its power electronics systems were developed to be compact and withstand high temperatures.


The DGC system comprises a number of compressor modules including a surface control system that takes a local power supply and changes it to produce a direct current supply of greater than 2000 volts. A custom ESP-type cable several thousand feet long transfers power and communications cables downhole to the installed DGC.

Downhole power electronics systems invert the supply to variable frequency alternating current that drives permanent magnet motors at the heart of each compressor module. A compressor module is driven by each inverter in the downhole power electronics module. These are mounted in series to provide the required pressure ratio over the inlet gas conditions.

CET said the DGC can be deployed at a depth with suitable temperature and flow characteristics to deliver the intended pressure ratio and flow rate. This is typically between 5000 and 10,000 ft. (1524 and 3028 m). The DGC can produce into production tubing or into the well casing and current projects are exploring both approaches. Completions are specific to the wellsite and any specific regulations in force.

The company added that the early development DGCs are thought to be most effective in gas wells with liquid loading — liquid at the wellhead but dry lower down (where the DGC can be positioned) — and with 7 in. (17.8 cm) casing or greater.

They are also estimated to be most effective at deployment depth (greater than 5000 ft. [1524 m]), flowing bottom hole pressure between 40 and 300 psi (2.7 and 20.6 bar) producing between 2 and 10 MMcfd (56 and 283 x 103 m3/d) with a remaining lifetime of between one and three years without intervention. There should also be no solids or brine in the gas stream and low levels of condensate at the base.

The DGC has the ability to compress gas with a limited liquid content. Initial well tests will be lightly liquid-loaded wells to establish dry performance before moving on to explore the operating envelope, Rigby said.

However, CET said it is working to tackle various technical challenges, notably the miniaturization of compressors prompted by the need to fit the entire compressor and motor drive system inside a well casing, or in the surface variants within a slightly larger but still limited pipe dimension.

Another test is coping with aggressive environments. A gas stream can contain fluids of various compositions, including hydrogen sulfide in some cases, and solids that can damage or corrode parts of the system.

CET’s work also focuses on power electronics in high temperature operation. Cooling is a key challenge as the switching of high-voltage power supplies introduces heat that must be managed within a confined space where cooling media are limited. Furthermore, while the system is intended to have a long service life, it must be reliable and low cost to attract users, the company added.

Corac said it is addressing these challenges in a number of ways. They include using frictionless, dry start/stop hydrodynamic oil free gas bearings that work by frictional gas entrainment to draw a film of gas between the faces and “lift” the shaft so it floats in three dimensions. A high shaft speed is necessary to maintain a stable gas film. Low friction in the low-gas density environment leads to high efficiencies and the specific load does not increase with gas density.

CET’s system also uses an advanced permanent magnet motor with a temperature capability up to 428°F (220°C) to withstand downhole conditions and a high power density stator that is compact to fit within the constrained space in the pipe, although difficult to insulate. The DGC also uses a modular design that reduces build time, has high integrity joints between modules and also plug-and-play IGBT modules with integrated cooling fins in the production gas stream.

This year, a DGC was deployed for the first time in a producing gas well in Texas. The successful early stage running was completed with more than 140 operating hours logged.

According to CET, the trial has shown that the DGC system is capable of operating at well depths greater than 6000 ft. (1830 m), where it encountered conditions as harsh as it is likely to meet in the intended application wells.

The compressor modules ran at high speeds in the production gas stream, the electronics module performed controlled start, stop and speed control functions and the communications system relayed data to the surface control systems as expected.

“Through this trial, the DGC has shown it can function at inlet temperatures approaching 212°F (100°C) and with condensate and other fluids in the gas stream,” Rigby said. “Through the multiple start and stop procedures within the well plus retrieval and redeployment events the system has shown itself to be resilient in day to day operation.”

After the tests were completed, Phil Cartmell, Corac Group CEO, said, “We feel this is a significant event in the development of high-speed compression for the energy industry.

“Our engineers have worked close- ly with our partners in the field and have taken our technologies to work successfully in a place where no compressor has ever been. There is still a lot of work to do, but this first proof of operation is a positive step towards the technical readiness of the system and its future commercial potential.”

In July, CET signed a master services agreement with BP Trinidad and Tobago (BPTT). This five-year agreement provides commercial terms to enable BP’s procurement of development, production, testing and installation of compact gas compression systems.

The agreement builds upon feasibility work carried out for a system to be deployed on an offshore gas production platform operated by BPTT. The compression systems will use CET’s core technology with the addition of some established subsystems provided by supply-side partners.

CET has started a funded feasibility study for Tullow Oil to focus on wellhead compression on a gas production platform in the southern North Sea. It also is in discussions with a number of other potential partners.

[the_doctor] 05/12/2014 10:39

Would be nice to see this up towards 6p/share, with a positive year end trading update then taking it back to the 8-10p range

[arf dysg] 02/12/2014 18:01

empirestate, a battered mince pie? Perhaps in Newcastle.

[alchemy] 02/12/2014 17:18

Now it seems UK marginal costs per barrel is $40 and Saudi based on oil wiht its "oilfare" state needs $100 per barrel ( Telegraph ).

[empirestate] 02/12/2014 14:17

looks like another buying op coming soon, looks pretty harshly battered today.

[arf dysg] 02/12/2014 13:32

Oh! Oh! Oh! The share price is dropping like a year-old mince pie going down a natural-gas well.