By Agung Aang on Friday, Oct 28th, 2011, at 03.45 PM
It has been years and decades, Indonesia is experiencing problem with it’s energy resources, the problem mainly on how to well optimize the utilization and exploration of it’s all natural and energy resources for the benefit of the people. The Indonesia is known to be one of the country who has so enormous natural and energy resources, especially on Natural gas. Becoming one of the big exporting countries of The natural Gas for years, Indonesia is so rich with gas reserves which are scattered almost all over the places through out it’s archipelago territories, covering both on-shore and off shore reservoirs. Unfortunately not all of them are as big as Arun, Bontang, Tangguh and or Masela (recently been developed) in the economic scale. Plenty of them in fact having only minimum / small scale reservoir, that’s only able to deliver gas less than or in the minimum range of 5 – 20 mmscfd. They are used to be called as “stranded / un-developed gas reserves”. That has in fact made them not so economic to be developed further by only employing the existing conventional technology known in the market.
Believed as of date only less than 50% of the country’s total Natural Gas reserves of about 90.3 Tcf (proven reserves) had successfully been developed for further monetization, the rest are still yet to be developed mainly due to such reason.
Another related problem, the Indonesian have to deal with is the imbalances gas supply-demands through out it’s wide spread territory areas, in lot of cases the gas wells(reserves) or gas supply areas located remotely distances from the gas market areas where all the industries and or power plants consuming the gas are located.
How to transport the gas from the supply areas in to the market areas in such away still within the economies of scale, be it through pipe-line and or shipping, had became another issue here. Again this has to be put in to the wholly considerations, when certain gas reserve is about to be further monetized, as whether the reserve contained is worth for the whole development cost (including plant production cost as well as the transport cost).
The above mentioned 2 main issues had so far always stand before and in fact had prevented them to make further development of many Indonesia’s small (stranded) gas reserves come in to reality. Therefore Indonesia will definitely need an innovation technology that can help them to get away from such hindrances, in the efforts to best utilize their small scale reserves.
Pressurized LNG concept was firstly introduced by ExxonMobil R&D Team in early 2006, similar concept was also introduced very recently by DSME Team. The concept what they called and patented as Cluster LNG.
The concept was in principle offering a new stage condition of the LNG in to the market. Under normal circumstances the conventional LNG was attained at the temperature of –163 deg C in the atmospheric pressure, hence in The Conventional LNG Processing (Liquefaction) Plant, natural gas was liquefied by certain thermal process up to the temperature of – 163 deg C.
Whilst in the new concept of Pressurized LNG, the stage of liquefied Natural Gas was attained and kept at the temperature only up to –110 deg C however instead, the pressure maintained at 20 Bars. In this case the total energy utility consumed in the gas liquefaction processes was much less compared to those consumed for the conventional processing. As the consequences, the cost involved in such process was eventually decreased quite significantly. The decreasing cost were mainly due to the less investment cost (CAPEX)involved in procuring the Plant, because of much less complexity and numbers of equipment involved in the Processing Plant, as well as due to the less no of expenses (OPEX) involved for the utility and consumables used through out the processes.
Decreasing numbers of investment (CAPEX) due to it’s less no of equipments and it’s complexity level, claimed to be as much as 50% compare to the conventional processing plant, thus also happens in the processing cost, as the cost different to bare the energy consumed in the thermal process to bring down the liquefied gas temperature up to –163 deg C compare to the same effort to get the temperature down only up to –110 deg C is quite significant, claimed to be not less than 50% off.
The less level of complexity as well as less numbers of equipment involved in the plant, happens to be because of this newly concept was told to be in tolerance to the lower quality of gas in it’s processing plant (i.e. higher CO2 content, water & sulfur content, etc), therefore no massive gas pre-treatment equipments shall be required in this case. As an illustration a certain maximum standard of several PPM of CO2 content required by conventional plant, instead this will allow up to 1-2% content.
On top of all above mentioned advantages, on the other hand of course there would always be some trade-off on this new concept technology compare to the conventional one, which was eventually known to be as good as on it’s LNG containment system.
As the LNG would be kept and maintained at 20 Bars of pressures, the existing conventional containment system definitely wouldn’t be able to hold such pressure longer. Therefore a new technology of containment system that is able to bare and retain the 20 bars pressure need to be applied in this newly concept. A specific material and designs as HSLT (High Steel Low Temp), Carbon Steel, even Composites are employed in this new containment system. The rest would be all the same as normal membrane system but with pressurized stages.
This new system/technology will off course also bring the consequences in the cost (CAPEX), especially on the fabrication cost of the tank containment it self, it was told to be as much as 20% – 30% more expensive at a given comparable specs compare to the conventional system. One might have questioned as whether this new containment system would be able to contain any normal conventional LNG, yes it would, if it can bare the pressurized LNG for sure it would be able to contain the conventional one.
More over, it’s also told that at a given volumetric capacity, the new containment system would only be able to contain less no of gas in a certain unit of energy. In fact it could hold only 20% less gas in volume compare to the conventional system, this off course would be of another set back. It has very much correlation with the unit cost of transport / shipment cost of the gas (OPEX) at the end of the day.
The fact would off course drives the higher unit shipment cost of the gas per certain unit of energy compare to the stage of the shipment using the existing conventional technology.
In a whole, it seems we still need to be careful of before come arrive to the conclusion that the concept is really fit and economically viable for the development and monetization of a small scale (“stranded”) gas reserves in Indonesia. A proper analysis study on it’s pros and cons, as well as a detailed engineering examination and precise calculation need to be done though roughly to be addressed to the remaining doubts of the feasibility of such new concept.
Despite of all doubts that might arise, I would say that the concept is indeed giving some short of hope, in fact I would say that it really make sense, brilliant and convincing enough, sufficed us with an alternative to be able to answer the question as earlier mentioned at the beginning of this note.
Is this really the right answer? Well, it seems like we will have to wait until any pioneer pilot project come to the stage of commercialization to be of sure, in the mean time I would say, yes I do have confident on it.
End of Oct 2011 
