17th April 2018
Engr. Khondkar Abdus Saleque

Senior policymakers are under illusion that the magic of planned LNG injection into national gas grid would cater for the mid-term energy security of Bangladesh. EMRD and Petrobangla are optimistic of 1,000 MMCFD LNG injected to National Grid by December this year and 500 MMCFD LNG injection by end April 2018. There are valid reasons for experts apprehending that neither would happen and Petrobangla may have to account for payment penalty to FSRU owners and operators undertake-of-pay contract. This may create embarrassment for the government in the election year as major gas using industries are promised of quality gas supply commencing soon. Power system is also expecting additional supply of gas this summer for ensuring loadshedding free power supply.

GTCL Challenges

GTCL as owner and operator of national gas grid has been stressed beyond its limit with the very challenging task of constructing too many difficult gas transmission infrastructures in challenging ROW within very tight time frame. We are not sure all these pipelines have been designed after proper transmission system simulation, risk analysis and assurances of capacity gas supply.

Cross country Pipelines in Bangladesh can be constructed only from November to April monsoon corridor. Every piece of construction materials requires to be imported from abroad. The construction needs special skill and stringent quality control, which are beyond the grasp of ordinary policymakers dictating GTCL in every project. Pipeline construction is not a piece of cake of ordinary individuals.

Only a hand full of Bangladeshi pipeline contractors are truly capable for 36 and 42” OD pipeline construction maintaining the quality. Still policymakers insisted several contractors constructing different sections of major pipelines accounting for additional mobilization and demobilizations, individual sections testing.

Fortune favoring GTCL and KGDCL may be in a position to utilize up to 250 MMCFD (Chittagong Ring Main) and 120 MMCFD through spurlines to KAFCO and CUFL by June 2018. The construction of Anwara-Faujdarhat pipeline under no possibility would be completed before the advent of monsoon with critical Karnaphuli river crossing still outstanding. There are ROW issues and some materials have also not arrived yet. There is no possibility that 90km 42-inch OD Maheshkhali–Anwara parallel pipeline completed before December 2019. GTCL and KGDCL also need to conduct onstream pigging of Chittagong Ring Main and Bakhrabad–Chittagong gas transmission pipeline for eliminating the possibility of condensate influx into terminal station post LNG injection. Gas flow direction would be reversed and at higher operating pressure upto MAOP would push all accumulated liquids and sludge to terminal stations.

Energy Metering and Gas Mixing Stations

LNG would generate bone dry gas. It will have specified heating value. There needs to have a mixing station at Anwara CGS, at Faujdarhat Manifold Station of Anwara Faujdarhat Pipeline and elsewhere, where LNG converted gas would mix with national grid gas. All these would need custody transfer metering facility from where gas will be mixed. Hope GTCL has required experienced officers for chromatographic analysis of gas and Energy Metering at Maheshkhali CT Station and Elsewhere at delivery points.

National GasTransmission Grid Architecture

GTCL, the unbundled Petrobangla mid-stream company has the natural monopoly of owning and operating the high pressure gas transmission system of Bangladesh. It evacuates gas from both National Production companies (BGFCL, SGFL and BAPEX) and IOCs (Chevron, KrisEnergy) and delvers to Petrobangla distribution companies TGTDCL, BGDCL, KGDCL, PGCL and JGDCL. Almost all the pipelines are built in accordance with ASME B 31.8 standard with Maximum Allowable Operating Pressure (MAOP) of 1000 PSIG (ANSI #600). The only ANSI #400 Pipeline is 24” OD 178 KM long Bakhrabad–Chattogram Gas transmission pipeline. The design philosophy of this pipeline was to transport gas from North Eastern and Central Region towards South Eastern region of Bangladesh. There was no perspective planning for considering reverse flowing of gas through this pipeline. Consequently 15 mainline valves are all unidirectional and pig launchers are at Bakhrabad and Feni ICS and Receivers are at Feni ICS and Faujdarhat CGS. We hope GTCL planning took this into account while planning reverse gas flow from Chittagong towards national gas grid for the rest of Bangladesh.

Pigging of Pipelines

It is business as usual that gas transmission pipelines are swabbed, pigged and hydrostatic tested prior the commissioning post construction. Commissioning is also done through series of pigging. Pipelines carry transmission quality gas (less than 4 PPM water and 2lbs per million liquid hydro carbon). The quality of pipeline quality gas is monitored by dew point testers at every Custody Transfer Metering Station of transmission system inlet. Even then all transmission pipelines require routine on-stream pigging to clean these of accumulated liquids and sludge and occasional intelligent pigging for metal loss. Unfortunately many pipelines of Bangladesh have never been pigged after commissioning and only few had on-stream pigging before. Only 14” OD Titas–Narsingdi–Demra pipeline had intelligent pigging carried out once. Experts believe that there may be significant amount of accumulated liquid and sludge at the lowest points of different pipelines. The immediate concerns are Chittagong Ring Main Pipelines where higher pressure delivery post LNG injection may create flooding to different CMS of bulk consumers and HPD DRSs. The reverse flow of gas from Fuajdarhat towards Bakhrabad would also need reconfiguring pig launchers and receivers. We hope Petrobangla and GTCL advised these to EMRD policy makers and have plans for conducting pigging.

Present Situation

GTCL is implementing two critical gas transmission pipelines now for evacuating the LNG from FSRUs at Mahekhali. The existing 30”OD Maheskhali–Anwara 90 KM pipeline may be connected to ExcelerateFSRU by the middle of April as the outstanding works of Custody Transfer metering (CTMS) station at Maheshkhali is going to be completed soon. The pipeline would need pigging and swabbing before commissioning with LNG converted gas. We are not very sure at what state the remaining section of the pipeline was left underground after construction.

Off course LNG import is one of main option for Bangladesh for confronting the ongoing fuel supply crisis. Given the advent of monsoon these works may take till End May or middle of June. The earliest gas can be transported to Anwara CGS may be early to the middle of June 2018. The spur line from Anwara CGS to Shah Mirpur.

Own production from discovered under operation gas field is fast depleting and there is no possibility of discovering a large enough new gas resource for meeting the present and emerging gas crisis. The existence of extensive national gas grid extending from Maheshkhali to Khulna would also assist in transmission of gas to all over the gas franchise. But we must also judge whether national gas grid is ready to evacuate the 4000 MMCFD planned for import by 2025. GTCL is burdened with huge task of constructing billions dollars worth of gas transmission infrastructure without being confirmed how much LNG would be actually imported. GTCL has been compelled to construct some major infrastructure like Bibiyana–Dhanua pipeline, Compressor stations at Ashuganj and Elenga, Transmission Pipeline all the way to Khulna and Ashuganj–Bakhrabad Loop line. The infrastructure would never be utilized even to their 50% capacity given the present situation and emerging scenario. In future all new gas supply would come from greater Chittagong region.

Suggestions

GTCL/KGDCL must immediately run few poly pigs through the Chittagong Ring Main arranging off loading condensate and sludge at CGS at Faujdarhat. At the same time few foam pigs should also be run in Maheshkhali to Anwara pipeline prior to running commissioning pigs again for LNG injection. Chattogram Ring main in its present state may only take 200-250 MMCFD. Hope GTCL/KGDCL by this time have constructed spur lines for KAFCO, CUFL and Power Plants at Shikalbaha. If so about 400 MMCFD gas from Anwara CGS can be transported for Chittagong area in 2018.

This will leave 100 MMCFD+200 MMCFD= 300 MMCFD available for gas grid nationwide post 500 MMCFD LNG injection.GTCL must plan how this gas can be effectively transported to other areas. Some works may be required at Bakhrabad Gas field hub. But it must be kept in mind all the time for emergency response. Gas flow may require changing directions as and when required.

BKB–CTG pipeline can no longer be operated about 800-850 PSIG for its design restriction. There should a pressure regulation station constructed at Faujdarhat manifold of Anwara-Faujdarhat pipeline as under construction Faujdarhat–Feni-Bakhrabad would be operated at 1000 PSIG. There is no way Anwara–Faujdarhat Pipeline would be completed before monsoon.So GTCL must plan on stream pigging and Intelligent pigging of Bakhrabad–Chattogram Pipeline engaging competent contractor before injecting gas in the reverse direction. All MLVs must take of gas actuators as these were set considering unidirectional flows. This pipeline cannot ever be operated by SCADA as it will require flowing in either direction now.

GTCL has obliged to EMRD and Petrobangla poor planning without considering the pros and cons of the implications and operational philosophy. GTCL must be compensated with higher wheeling charges to recover its investment as scheduled in approved DPP. We are not sure all FSRUs and land Based LNG terminals would come on time. GTCL financial backbone would be severely impacted. Hope BERC would take all these into consideration. As BERC issue license to GTCL it must see that all investments of its licensees are logically made.  GTCL is suffering from bad investments for ill-conceived Bibiyana–Dhanua pipeline on top of Ashuganj and Elenga Compressor stations. Pipeline to Khulna is almost running dry.

 

Engr. Khondkar Abdus Saleque;

NRB, Energy Professional


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