PV GAS: The initiative to profit more than 30 billion

In 2019, Vietnam Oil and Gas Group (PVN) awarded the decision to special classification (category A) for the initiative “Restage Bundle pressure compressor GTC-A/B DGCP rig” with the value of benefiting businesses more than 30 billion.

The initiative was implemented by Nguyen Tan Hoang and co-authors: Trieu Quoc Tuan, Nguyen Minh Tuan, Nguyen Phuong Dao, Bui Tan Hung, Pham Thanh Tu, Do Ngoc Tan are leaders and engineers of Southeast Gas Transportation Company (ER), Gas Services Company – 02, a unit of Vietnam Gas Corporation (PV GAS).

Dragon – Tortoise Oil Platform (DGCP) is a project invested by PV GAS and put into operation since November 2010. The Southeast Gas Transportation Company is assigned by PV GAS to manage, supervise the operation and exploitation of gas works – Vietsovpetro is the unit hired directly by PV GAS to operate the project. The project is designed to consist of 2 complexes of high-voltage air compressors with a compressed capacity of 900 thousand m3 of gas per day and night, in order to collect all the companion gas of the Dragon mine area – Tortoise to compress back into the general gas lift system of Vietsovpetro. The additional gaslift of dragon compressor (DGCP) contributes to the part of the gas lift demand from the Central Compressor Rig (CCP), indirectly increasing the amount of gas supplied to the shore to meet part of the gas needs of the Southeastern market.

Over the course of nearly 10 years of operation, the staff and engineers working here have researched and applied many technical solutions and scientific initiatives to ensure the stable, reliable and effective operation of the equipment system; contribute to increasing the ability to collect companion gas and increase the amount of gas lift supplied to the Dragon mine from the DGCP platform.

In the initiatives that can be mentioned in the second half of 2015, two high-voltage compressors (GTC-A/B) on the Dragon mine compressor have declined compressed capacity very quickly after just over a year of overhaul, losing about 20% of traffic compared to the previous time. The decrease in the capacity of 02 compressors not only affects the increase of PV GAS’s gas output to shore, but also affects Vietsovpetro’s oil extraction activities. Worried about that situation, the group of officers and engineers of Southeast Gas Transportation Company was determined to quickly find solutions to overcome.

With the close and timely direction from the Board of Directors and above all, internal solidarity, the authors have coordinated with related units such as Gas Services Company, Vietsovpetro Gas Mining Enterprise, Solar (the manufacturer of these two compressors) to find the most optimal solution possible.

After a long time of researching, reviewing and excluding the reasons why the authors have found specific causes that come from two main factors: One is the dirty input gas source, which contains many paraffins caught in the compressor that stains the wing layers of LP, HP Comp and the increasingly light air density compared to the design makes compression more difficult and requires more and more the ability to the turbines were operating at full capacity. The second is due to the in-house problem of the machine because the compression ratio distribution between the LP Comp and HP Comp levels is not really suitable. These errors did not appear immediately after the overhaul, so engineers had difficulty finding the cause.

From the above analysis, the parties have come up with a solution to control the source of gas inputs. Implement a restage bundle to match the current nature of the air source to ensure the compressed capacity of the compressor and the operating time of the compressor to the next overhaul cycle.

Mr. Nguyen Tan Hoang shared that GTC-A/B compressors are two-level centrifumatic compressors, each of which is composed of consecutive wing floors, the air flow pressure through the compressor will be gradually lifted through the wing floors. The shape, structure and number of these wing layers depend on the compressor line, the output input pressure, the properties of the compressor fluid. The specific case for the GTC-A/B compressor on the DGCP truss is that the properties of the compressor fluid (gas ratio) have changed from the design, so it is necessary to perform restage – reconfiguration of the compressor by changing the wing layers in shape, structure, quantity to match the current operating parameters.

When the solution is put into practice on the gas collection system in Dragon Mine – TortoiseShell, the machine operates safer and more stable; level 1 (LP) input temperature decreased by about 10oC (175oC to 165oC); Output through the machine increased from 3% to 7%, total stable output in the range of 1,030-1,080 ksm3 /day and night. This result is evident in specific figures with the increased gas counted to have benefited PV GAS as well as PVN over 30 billion.

Sharing about the solution, the authors said that initiatives and improvements need the intellectual mobilization of the collective to quickly put into practice. In the group of authors, there are people with the title of director, deputy director but when there are tasks, especially incidents, problems arise, leaders do not hesitate to difficulties, all form a solid link for the goal of completing common tasks. It can be said that “the difficulty of the smart”, through actual labor initiatives are born not only bring high economic benefits but also promote the emulation movement in the unit.

Monitoring the operation of compressors at air conductive works is a relatively complex job, new technology is constantly updated, constantly learning, updating knowledge to keep up with change is necessary. As the elite workers of the industry, despite the high achievements in research, launched many initiatives widely applied but the authors never satisfied with the achievements. In them, they always have passion in work, desire to devote and self-study spirit to improve professional skills to meet the needs of work, apply science and technology in the process of management and production.

Productivity and Quality Office