BiographyMavis Sika Okyere (née Nyarko) is a Senior Pipeline Integrity Engineer at Ghana National Gas Company. She is an expert in risk-based assessment, pipeline integrity, corrosion monitoring, and cathodic protection design. She has experience with subsea structural engineering, piping & pipeline engineering principles as applied to both onshore & offshore conditions.
Mavis studied MSc. Gas Engineering and Management at University of Salford, United Kingdom and BSc. Civil Engineering at Kwame Nkrumah University of Science and Technology, Ghana.
She worked with LUDA Development Ltd, Bluecrest College, INTECSEA/Worleyparsons Atlantic Ltd, Technip, Ussuya Ghana Ltd, and Ghana Highway Authority. She has published in several books and journals, and is a member of many National and International bodies such as the Institute of Gas Engineers and Managers (IGEM).
Areas of Research / Professional Expertise
• Corrosion protection
• Fixed offshore platform: structural design for fire resistance
• Stress-based design of pipelines
• Reducing third-party damage to onshore pipelines
• Fire safety retrofitting
• Sizing of gas pipelines
• Engineering design of oil and gas pipelines
• Pipeline flow analysis (specifically; gas flow analysis, hydrocarbon liquid flow analysis and pipeline flow improver)
By: Mavis Sika Okyere
Subjects: Engineering - General
Ghana is expected to boost its power generation by 2020 with the introduction of two LNG projects, namely, the Tama LNG Terminal Project and a small-scale virtual LNG pipeline project.
The Tema LNG Terminal project consists of a Floating Storage, Regasification Unit (FSRU) with expected capacity of 250 mmscfd expected to be completed in 2020. The initial contracted supply amount is about 180 mmscfd. The project is controlled by Helios investments who have signed an agreement with China Harbour Engineering Company for the construction of the FSRU.
GNPC has signed a-12-year agreement with Rosneft of Russia for the supply of the LNG. GNPC earlier in 2017 signed an agreement with a private company, Quantum Power for the latter to construct and operate a 500 mmscfd floating LNG storage, regasification and delivery facility moored offshore Tema.
The US$550 million facility which was supposed to be operational
this year apparently fell through and has been replaced with the
The small-scale virtual LNG is a virtual pipeline project to supply gas to SunonAsogli and Trojan power plants.
It would comprise seventeen ’52-cubic-metre’ LNG trucks ferrying LNG from small scale LNG ships berthed at the TemaPort; eight trucks at the loading gantry at a time and additional eight trucks moving every night to deliver the fuel to the 560 MW gas fired SunonAsogli Power Plant thermal plants.
Loading is estimated to take an average of an hour. Initial
contract quantity is said to be 60 mmscfd.
The source of LNG for the small-scale project is the LNG2Africa initiative; an Equatorial Guinea initiative to sell small scale LNG for utilisation in Africa.
This was disclosed by Mrs. Mavis Sika Okyere, a Pipeline Integrity Engineer, Ghana National Gas Company, during a presentation at the LNG West Africa conference 2019 in Accra, Ghana.
According to her, current gas demand in Ghana is primarily for power generation and is focused around power plants at Aboadze and Tema.
Industrial demand is also concentrated in these areas. Future power generation plans include expansion and new projects at these sites and also new projects at Atuabo, Esiama and Domunli.
The tables below demonstrate the need for additional feed gasfor gas fired power generation in Ghana between 2016 and 2025 beyond supplies from local production (TEN, Sankofa, Jubilee) and West African Gas Pipeline (WAGP) gas supply.
“The Jubilee Field produces 120 mmscfd TEN Field 60 mmscfd and Sankofa 180 mmscf totaling 360 MMscfd. Considering this current production, the Atuabo gas plant has the capacity to produce 150mmscf as against the estimated 560 mmscf of natural gas demand by the country daily.
Eni have constructed an Onshore Receiving Facility (ORF). Ghana National Gas Company together with Eni has constructed a tie in to GNGC pipeline and has increased daily production to 405 mmscf. However, there is still deficit of 155 mmscf in Gas supplied for power generation,” she pointed out.
She however noted that the estimated deficit of about 155 mmscfd is within the breakeven point for a typical 200-250 mmscfd LNG regasification facility.
Therefore, to improve the overall power supply in the country, she proposed “Investments in liquefied natural gas as an alternative gas supply to augment the limited local and unreliable gas from the West Africa Gas Pipeline from Nigeria should be pursued.”
LNG supply option however would be relatively expensive compared to local or the WAGP gas but cheaper than crude oil.
LNG imports would supplement domestic gas to make up adequate supplies both for power and industry requirement such as for the anticipated production of fertilizers (urea), alcohol (methanol) and other petrochemicals.
However, according to the Commercial Manager, Tallow Ghana Limited, Mr John McLaughlin, noted that Ghana has significant domestic gas offshore, enough for the next decade, and therefore does not need to import LNG.
He noted that the TEN and Jubilee oil production increases with increasing gas demand, adding that, “A robust Ghana gas market will also support further investment in offshore exploration.”
Stating that LNG is more expensive than domestic gas, McLaughlin said the government of Ghana benefits from a far higher share of value from domestic gas production compared to LNG.
“LNG import “shuts the door” on offshore gas development for years. TEN and Jubilee oil production increases with increasing domestic gas offstage,” he indicated.
By: Mavis Sika Okyere
Subjects: Materials Science
Explore our collection of notable titles by women in the field!
By: Mavis Sika Okyere
Subjects: Engineering - Civil
October 10th is Ada Lovelace Day! Today the world celebrates all of the accomplishments of women in science, art, design, technology, engineering, and math. Each year, Adafruit highlights a number of women who are pioneering their fields and inspiring women of all ages to make their voices heard. Today we will be sharing the stories of women that we think are modern day “Adas” alongside historical women that have made impacts in science and math.