Gas Flow Design Result: Phase 3
1,321mmOD x 12.0MPa trunkline of 4,800t/hr capacity, which is identical to Pacific Route, is layed along Japan Sea offshore. That Installment is able to supply russian gas to Nagoya and Osaka industrial areas.
Additional 1,422mmOD x 7.5MPa on-land piping is installed in Hokkaido. The pipeline in Tokai region is to be reached to Tsuruga in Japan Sea Route to back-up gas delivery to new areas in emergency cases.
Connecting lines between Pacific and Japan Sea Routes shall be completed at Atsumi - Souma, and at Tsuruga - Nagoya to secure back-up capacity. The batch back-up system from LNG storages at Wakkanai and at Souma during Phase 1 &2, can be improved to continuous pipeline network system.
Specifications of the on-land trunkline in Tokai, Nagoya and Osaka areas were set to apply the allowable pressure limit of 7.0MPa according to existing natural gas regulations, i.e., 1,422mmOD x 7.0MPa of 28MMTPA capacity.
Taken into consideration busy sea traffic situation, offshore trunkline in Seto Sea shall be sized according to same specifications as on-land pipings of 7.0MPa.
Gas Transport in Hokkaido 6,900t/hr
- Hokkaido 500t/hr
Gas Transport in Pacific Route 3,900t/hr
- Tohoku 700t/hr - Kanto 800t/hr
- Tokyo 1,700t/hr - Tokai 700t/hr
1,422mmOD x 7.5MPa identical on-land piping is installed along the same route in Hokkaido to ensure 6,900t/hr gas transport. Additional 3 stations are needed to supply 38MMTPA in Pacific Route.
3 booster stations are to be provided for emergency back up purposes, and no operations are necessary normally.
Gas Transport in Japan Sea 2,500t/hr
- Japan Sea 700t/hr - Nagoya 700t/hr
- Osaka 900t/hr - Seto Sea 200t/hr
Planned gas transport in Japan Sea Route is approx. 50% of rated trunkline capacity and provisions of booster stations at only 4 locations are enough to supply specified gas delivery.
No boosters are required in Seto Sea and in San-In regions during Phase 3 stage.
During emergency, for example, by Niigata earthquake accident, the gas delivery to Nagoya and Osaka areas can be secured via Pacific Route.
Bypassing Niigata region, natural gas in Japan Sea Route shall be merged to Pacific Route via Atsumi - Souma connecting line and transported to Nagoya by using Tokai back-up line.
That line is merged to Japan Sea Route via Nagoya - Tsuruga connecting line. And delivery to Osaka area is supplied in normal Japan Sea Route.
Accordingly, 100% delivery is possible except for Niigata area.
The batch recovery system used in Phase 1 &2 is applicable to Niigata area.
to Gas Flow Design Phase 4