Petrovietnam Journal

Diffraction imaging for basement fault-fracture prediction: Application to an oil field in Cuu Long basin

Ta Quang Minh — 2020-10-30

Improvement to the image of fractured granite basements is among the most sought-after goals for processing seismic data in Cuu Long basin, the most proliferous petroleum basin. Unlike a clear layering structure of the sediment, fuzzy images of the granite basement are often the source of confusion for interpreters to identify which structures are presented inside it. In such a low signal-to-noise ratio (SNR) environment, extracting geological information such as fault systems and fracture becomes challenging. In this study, diffraction imaging is employed in an effort to identify and enhance the fault system inside the basement. The comparison of the study result with various standard post-stack attribute approaches shows the effectiveness of the diffraction imaging method.

Preliminary assessment of the characteristics of Late Miocene - Quaternary intrusive and extrusive magmatism in the Tu Chinh - Vung May basin, southeastern continental shelf of Vietnam

Bui Huy Hoang — 2020-10-30

Based on the seismic and well dataset provided by the Vietnam Petroleum Institute (VPI), the authors have mapped and described the characteristics of the distribution and morphology of magmatic bodies as well as relatively dated them in the Tu Chinh - Vung May basin and adjacent areas. To distinguish magmatic bodies from other amplitude anomalies such as gas zone or carbonate build-up/layers, multiple criteria were used such as cross-cutting relationship, associated deformation of surrounding strata, morphology and geological relationship between different magmatic bodies. Intrusive bodies are usually sheet-like or saucer-shaped sills that cross-cut strata and even deform overlying strata, while extrusive bodies are usually cone-shaped vents/volcanoes or extensive lava sheets that conform to strata. The magmatic bodies often distribute in clusters around one or more magmatic conduits. Middle Miocene and older syn-rift faults controlled the pathway of the conduits. Magmatic bodies are more abundant closer to the East Sea spreading margin. Late Miocene - Quaternary magmatism is widespread in the study area in particular, and in the East Sea and adjacent areas in general. These activities took place after rifting and oceanic crust formation had ended, which is characteristic of magma-poor margins.

Inferring interwell connectivity in a reservoir from bottomhole pressure fluctuations of hydraulically fractured vertical wells, horizontal wells, and mixed wellbore conditions

Dinh Viet Anh — 2020-10-30

A technique using interwell connectivity is proposed to characterise complex reservoir systems and provide highly detailed information about permeability trends, channels, and barriers in a reservoir. The technique, which uses constrained multivariate linear regression analysis and pseudosteady state solutions of pressure distribution in a closed system, requires a system of signal (or active) wells and response (or observation) wells. Signal wells and response wells can be either producers or injectors. The response well can also be either flowing or shut in. In this study, for consistency, waterflood systems are used where the signal wells are injectors, and the response wells are producers. Different borehole conditions, such as hydraulically fractured vertical wells, horizontal wells, and mixed borehole conditions, are considered in this paper.
Multivariate linear regression analysis was used to determine interwell connectivity coefficients from bottomhole pressure data. Pseudosteady state solutions for a vertical well, a well with fully penetrating vertical fractures, and a horizontal well in a closed rectangular reservoir were used to calculate the relative interwell permeability. The results were then used to obtain information on reservoir anisotropy, high-permeability channels, and transmissibility barriers. The cases of hydraulically fractured wells with different fracture half-lengths, horizontal wells with different lateral section lengths, and different lateral directions are also considered. Different synthetic reservoir simulation models are analysed, including homogeneous reservoirs, anisotropic reservoirs, high-permeability-channel reservoirs, partially sealing barriers, and sealing barriers.
The main conclusions drawn from this study include: (a) The interwell connectivity determination technique using bottomhole pressure fluctuations can be applied to waterflooded reservoirs that are being depleted by a combination of wells (e.g. hydraulically fractured vertical wells and horizontal wells); (b) Wellbore conditions at the observations wells do not affect interwell connectivity results; and (c) The complex pressure distribution caused by a horizontal well or a hydraulically fractured vertical well can be diagnosed using the pseudosteady state solution and, thus, its connectivity with other wells can be interpreted.

Production technology solutions to enhance heavy oil recovery of marginal fields, offshore Vietnam

Tran Quoc Viet — 2020-10-30

The finding of heavy oil at Dong Do field of Cuu Long basin is a success in exploration. It could be considered as a large heavy oil field offshore Vietnam. Maximising reserve is a challenge to the operator when they think of a suitable development strategy to efficiently and economically exploit the field. Over the past decades, production technology application in heavy oil production has been widely developed in the industry. Apart from the thermal method, pumping technology makes remarkable advances by enlarging the drawdown created over the conventional gas lift in several heavy oil projects.

This paper presents all the production technology solutions that apply to the marginal heavy oil field offshore Vietnam. One of the major solutions is the electric submersible pump (ESP) and gas-lift (GL) combination method to enhance the wellbore lifting efficiency. In doing so, a series of solutions to improve heavy oil recovery have been conducted from design to pilot test whilst optimising the economic yield over the field life. Among them, the application of ESP and GL combination plays as the key driver to reinforce good production performance.

As a result, the design includes an electrical pump system coupled with GL back-up, all integrated with one to boost production and prolong well life. Beside that, closely monitoring and optimising is one factor to give the pump a longer life.

Solutions for upgrading gasoline products to comply with Euro V specifications in Dung Quat refinery

Le Hong Nguyen — 2020-10-30

Dung Quat refinery is under the management of Binh Son Refining and Petrochemical Joint Stock Company (BSR). Currently, Dung Quat refinery is facing opportunities and challenges from macroeconomic policies as well as the development trend of the oil and gas industry including the issue of improving product quality, enhancing operational efficiency and competitiveness to be able to survive and develop in a new situation.

In this article, the authors suggest solutions to upgrade Dung Quat refinery gasoline products to satisfy more stringent standards and environmental regulations. Standards here mean the Euro V standards set out in the EN 228:2008 applicable to gasoline/petrol respectively. Solutions proposed to overcome problems relate to benzene, sulfur and olefin content in BSR gasoline products.

The article proposes two basic solutions to upgrade the gasoline product quality of Dung Quat refinery with some preliminary estimates. Each solution has its own advantages and disadvantages. Depending on specific situations, the more suitable one will be selected. Detailed calculation will be performed if the product quality upgrading project is implemented.

Design and assembly of an apparatus system based on the Villari effect for detecting stress concentration zone on ferromagnetic materials

Doan Thanh Dat — 2020-10-30

This paper presents the study results on the fabrication of a structural integrity assessment apparatus by determining stress concentration zones in pressure pipeline and equipment. The apparatus uses a triaxial magnetic field sensor to measure magnetic field components in three axes Ox, Oy, and Oz, in the working range of the magnetic field from -300 µT to 300 µT. The investigation of the selfmagnetic leakage field by this apparatus in the API 5L steel specimens under tensile stress shows a high variation of the magnetic field at a steel elongation lower than 1 mm (corresponding to the elastic deformation state of the material). In the case of an artificial defect, the apparatus can detect a change in the magnetic field caused by stress concentration.

Digital transformation in oil and gas companies - A case study of Bien Dong POC

Tran Vu Tung — 2020-10-30

The fourth industrial revolution (Industry 4.0) with the breakthrough of internet and artificial intelligence has had a strong impact, changing all aspects of global socio-economic life. Digital transformation in the spread of Industry 4.0 is no longer a choice but has become an inevitable development trend for businesses to truly stand up to the times. Digital transformation is the transformation of business activities, processes, products, and models to fully leverage the opportunities of digital technologies, characterised by development, growth, innovation, and disruption. In particular, "digital disruption" is the situation when new technology competes with the traditional business way that we now often refer to under the concepts of cloud computing, big data, and internet of things (IoT). This competition will help businesses utilise digitised data and processes to create a new model that is more efficient and convenient. Digital technologies in oil and gas companies can have a significant business impact as it contributes to increasing hydrocarbon recovery, ensuring safety across the business ecosystem, and improving operational reliability. This paper addresses the oil and gas industry’s trends in digital transformation and the initiatives at Bien Dong POC.