An Initiative worth more than one million US Dollar
In 2019, Vietnam Oil and Gas Group (PVN) has rated Special (type A) for the initiative "Converting high-pressure compressors GTC-A / B for DGCP platform" which bring a benefit with the value more than one million US Dollar for the Enterprise.
The initiative was implemented by the author Nguyen Tan Hoang and his co-authors: Trieu Quoc Tuan, Nguyen Minh Tuan, Nguyen Phuong Cao, Bui Tan Hung, Pham Thanh Tu and Do Ngoc Tan who are managers, engineers of two enterprises directly under PetroVietNam Gas Join Stock Corporation (PV GAS): PVGAS South East Transmission Company (PVGAS SE) and PVGAS Services (PVGAS Services) company.
Maintenance team is discussing with Solar experts
The Dragon Gas Compressor Platform (DGCP) on Dragon field is a project invested by PV GAS and put into operation from November 2010. PVGas SE is assigned by PV GAS to manage, supervise the operation, and the Vietsovpetro Gas Enterprise is the operator of the platform.
The DGCP is designed and constructed with two high-pressure compressor packages with a capacity of 900,000-cubic meter of gas per day to collect all the associated gas of the Dragon field area to compress back into the general gaslift system of Vietsovpetro. The amount of additional gaslift of DGCP platform contributes to a share of gaslift demand from the Central Compressor Platform (CCP), indirectly increasing the amount of export gas to onshore to meet part of the Southeast region's gas market demand.
Over the nearly 10 years of operation, the managers and engineers working here have studied and applied many technical solutions and scientific innovations to ensure the stable, reliable and effective operation of equipment systems; contributing to the ability to collect associated gas and increase the amount of gaslift supplied to the exploitation of petroleum.
In the second half of 2015, two high-pressure compressors (GTC-A / B) on DGCP decreased their compressive capacity rapidly after one year of overhaul, losing about 20% of the gas flow compared to the previous time. The decline in capacity of the two compressors not only affected the increase in export gas to onshore, but also affected the exploitation petroleum activities of Vietsovpetro.
Concerned with this situation, the PVGas SE management and engineers were determined quickly the need to find a solution to overcome the difficulty. The author team collaborated with related division such as PVGAS Services, Vietsovpetro Gas Enterprise, Solar Turbines (the manufacturer of these 2 compressors) to find the best possible solution.
After a long period of research, review, evaluation and elimination of causes, the authors have found specific causes stemming from two main factors:
One is the dirty input gas, contains lots of paraffin, which is drawn into the compressor, which contaminates the impeller of low-pressure (LP) compressor and high–pressure (HP) compressor and the lighter density of gas makes the compression required more energy to operate compare to the design.
The other is due to internal problems because the distribution of compression ratio between LP Compressor and HP Compressor levels is not suitable. These errors do not appear immediately after the overhaul of the compressor so the engineers have a hard time finding the cause.
The maintenance team is pulling the bundle out of the compressor casing
From that analysis, the authors have come up with a solution: The source of input gas must be controlled. Implementing the plan of converting high-pressure compressors to suit the current nature of the gas source to ensure the compressive capacity of the compressor and the operation time of the compressor until the next overhaul cycle.
Representative of the author team, Mr. Nguyen Tan Hoang shared: GTC-A / B compressor is a 2-levels centrifugal compressor (LP Compressor, and HP Compressor), each levels is composed of the impellers, the gas flow pressure through the compressor will is gradually raised through the impellers rotating.
The shape, structure and number of the impellers depend on the compressor series, the outlet inlet pressure, the nature of the compressed fluid... The specific case with the GTC-A / B compressors on the DGCP platform is the nature of the compressed fluid (gas density) has changed compared to the design, so it is required to perform restage - reconfigure the compressor by changing the impellers of the shape, structure, quantity to in accordance with current operating parameters and current gas condition.
When the solution is put into practice on the gas compressor package (GTC-A/B) on the DGCP, the compressor operates more safely and stably; level 1 (LP) outlet temperature decreases by about 10 ° C (175 ° C down to 165 ° C); gas output through the compressor increased from 3-7%, the total output is stable in the range of 1,030-1,080 ksm3 per day. This achievement is clearly shown in the specific figures with the increase in gas calculated to have benefited PV GAS as well as PVN over one million US Dollar.
Sharing about the solutions, the authors believe that initiative and innovation are very in need of intellectual mobilization of the collective to put quickly into practice. In the author team, there are people with the title of director, deputy director, but when problems or problems arise, the managers do not mind difficulties, all forming a solid link for the purpose of accomplishing a common task. It can be said that, "adversity brings wisdom", through practical labor, the initiatives launched not only bring about high economic benefits but also promote the emulation movement to promote innovation and technical improvement in the enterprise.
Supervising the operation of the gas compressor platform is a relatively complex task, new technology constantly updated, so it is constantly learning and updating knowledge to keep up with technological changes is in need. As excellent employees of the Oil and Gas industry, despite high achievements in research, many innovations that have been widely applied, the authors have never been satisfied with the achievements. There is always a passion for work in them, the desire for dedication and the spirit of self-study, raising the qualifications to meet job requirements, applying science and technology into the management and production process.