scholarly journals Improved neural network model of assessment for interpretation of miocene lithofacies in the Vukovar formation, Northern Croatia / Izboljšani nevronsko-mrežni model za oceno interpretacije miocenskega litofaciesa v Vukovarski formaciji v severni Hrvaški

2018 ◽  
Vol 65 (3) ◽  
pp. 145-156
Author(s):  
Varenina Andrija ◽  
Malvić Tomislav ◽  
Mate Režić
Keyword(s):  
Neural Networks ◽  
Oil And Gas ◽  
Neural Model ◽  
Oil Reservoir ◽  
Well Log ◽  
Gas Reservoirs ◽  
Gas Reservoir ◽  
Lithological Composition ◽  
Northern Croatia ◽  
The City

Abstract The Ladislavci Field (oil and gas reservoirs) is located 40 km from the city of Osijek, Croatia. The oil reservoir is in structural-stratigraphic trap and Miocene rocks of the Vukovar formation (informally named as El, F1a and F1b). The shallower gas reservoir is of Pliocene age, i.e. part of the Osijek sandstones (informally named as B). The oil reservoirs consist of limestones, breccias and conglomerates, and gas is accumulated in sandstones. Using neural networks, it was possible to interpret applicability of neural algorithm in well log analyses, and using neural model, it was possible to predict reservoir without or with small number of log data. Neural networks are trained on the data from two wells (A and B), collected from the interval starting with border of Sarmatian/ Lower Pannonian (EL marker Rs7) to the well’s bottom. The inputs were data from spontaneous potential (SP) and resistivity (R16 and R64) logs. They were used for neural training and validation as well as for final prediction of lithological composition in the analysed field. The multilayer perceptron (MLP) network had been selected as the most appropriate.

The Development of an Oil Reservoir with Condensate Gas Cap

2012 ◽  
Vol 524-527 ◽  
pp. 1615-1619
Author(s):  
Heng Song ◽  
Lun Zhao ◽  
Jian Xin Li ◽  
Kou Shi
Keyword(s):  
Numerical Simulation ◽  
Oil And Gas ◽  
Oil Reservoir ◽  
Gas Oil ◽  
Gas Reservoir ◽  
Oil Rim ◽  
High Level

The development of gas-oil reservoir with condensate gas is more difficult than pure gas reservoir or oil reservoir. This article gives the example of G oil reservoir the development of gas cap and oil rim. According to the characteristic of the oil developing and the results of numerical simulation, the rules for oil and gas developing and developing time have been defined, by which the recoveries of gas, oil, and condensate oil will reach a significantly high level.

scholarly journals Development of a prmA genes quantification technique and assessment of the technique’s application potential for oil and gas reservoir exploration

2018 ◽  
Vol 36 (5) ◽  
pp. 1172-1188 ◽  
Author(s):  
Zhuo Ning ◽  
Ze He ◽  
Sheng Zhang ◽  
Miying Yin ◽  
Yaci Liu ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Quantitative Polymerase Chain Reaction ◽  
Oil Field ◽  
Gas Reservoirs ◽  
Gas Reservoir ◽  
Gas Field ◽  
Detection Range ◽  
Gene Copies ◽  
Application Potential ◽  
Sensitivity Specificity

Propane-oxidizing bacteria in surface soils are often used to indicate the position of oil and gas reservoirs. As a potential replacement for the laborious traditional culture-dependent counting method, we applied real-time fluorescent quantitative polymerase chain reaction detection as a quick and accurate technology for quantification of propane-oxidizing bacteria. The propane monooxygenase gene was set as the target and the assay is based on SYBR Green I dye. The detection range was from 9.75 × 108 to 9.75 × 101 gene copies/µl, with the lowest detected concentration of 9.75 copies/µl. All coefficient of variation values of the threshold cycle in the reproducibility test were better than 1%. The technique showed good sensitivity, specificity, and reproducibility. We also quantified the propane-oxidizing bacteria in soils from three vertical 250 cm profiles collected from an oil field, a gas field, and a nonoil gas field using the established technique. The results indicated that the presence of propane monooxygenase A genes in soils can indicate an oil or gas reservoir. Therefore, this technique can satisfy the requirements for microbial exploration of oil and gas.

THE DEVELOPMENT OF THE TIRRAWARRA OIL AND GAS FIELD

1984 ◽  
Vol 24 (1) ◽  
pp. 278
Author(s):  
H. T. Pecanek ◽  
I. M. Paton
Keyword(s):  
Carbon Dioxide ◽  
Oil And Gas ◽  
Gas Injection ◽  
Oil Field ◽  
Oil Reservoir ◽  
Gas Reservoirs ◽  
Gas Field ◽  
Associated Gas ◽  
Oil And Gas Field ◽  
Cooper Basin

The Tirrawarra Oil and Gas Field, discovered in 1970 in the South Australian portion of the Cooper Basin, is the largest onshore Permian oil field in Australia. Development began in 1981 as part of the $1400 million Cooper Basin Liquids ProjectThe field is contained within a broad anticline bisected by a north-south sealing normal fault. This fault divides the Tirrawarra oil reservoir into the Western and Main oil fields. Thirty-four wells have been drilled, intersecting ten Patchawarra Formation sandstone gas reservoirs and the Tirrawarra Sandstone oil reservoir. Development drilling discovered three further sandstone gas reservoirs in the Toolachee Formation.The development plan was based on a seven-spot pattern to allow for enhanced oil recovery by miscible gas drive. The target rates were 5400 barrels of oil (860 kilolitres) per day with 13 million ft3 (0.37 million m3) per day of associated gas and 70 million ft3 (2 million m') per day of wet, non-associated gas. Evaluation of early production tests showed rapid decline. The 100 ft (30 m) thick, low-permeability Tirrawarra oil reservoir was interpreted as an ideal reservoir for fracture treatment and as a result all oil wells have been successfully stimulated, with significant improvement in well production rates.The oil is highly volatile but miscibility with carbon dioxide has been proven possible by laboratory tests, even though the reservoir temperature is 285°F (140°C). Pilot gas injection will assess the feasibility of a larger-scale field-wide pressure maintenance scheme using miscible gas. Riot gas injection wells will use Tirrawarra Field Patchawarra Formation separator gas to defer higher infrastructure costs associated with the alternative option of piping carbon dioxide from Moomba, the nearest source.

scholarly journals Study on Rheological Properties of Nanofluids

2021 ◽  
Vol 2132 (1) ◽  
pp. 012049
Author(s):  
Yan-qing Bian ◽  
Pu-cheng Wu ◽  
Jing Hao ◽  
Quan Shi ◽  
Guo-wei Qin
Keyword(s):  
Shear Rate ◽  
Rheological Properties ◽  
Oil And Gas ◽  
Loss Modulus ◽  
Production Capacity ◽  
Tight Gas ◽  
Water Control ◽  
Gas Reservoirs ◽  
Gas Reservoir ◽  
Tight Gas Reservoir

Abstract Based on the previous research on the rheological properties of nanofluids by many scholars at home and abroad, to solve the problem that the viscosity of conventional polymer water control agents is large and cannot meet the demand for increasing production capacity in the process of tight gas reservoir exploitation, this paper takes self-made nanofluids as the research object, tests the rheological properties of self-made nanofluids by rheological experiment, and systematically studies the effects of concentration, temperature and shear action on the viscosity of nanofluids, and the dynamic viscoelasticity and thixotropy of nanofluids were discussed. The results show that the rheological type of nanofluid belongs to power-law fluid, but it is related to the shear rate. The viscosity of nanofluids increases with the increase of concentration; when the temperature increases, the viscosity of nanofluids decreases and the fluidity increases; under the shear action, the viscosity of nanofluid changes very little and has good shear resistance; the dynamic viscoelastic test shows that the storage modulus G´ of the nanofluid is larger than the loss modulus G”, showing elastic characteristics; the thixotropy test shows that when the shear rate is accelerated, the viscosity decreases with time, and when the shear rate is slowed down, the viscosity recovers rapidly with time, which has good thixotropy. The research results provide an important theoretical basis for further research on the application of nanomaterials in tight oil and gas reservoirs.

scholarly journals Influence of geological reservoir heterogeneity on exploitation conditions of Garadagh field / underground gas storage (Azerbaijan)

2021 ◽  
Vol 6 (2) ◽  
pp. 105-113
Author(s):  
A. A. Feyzullayev ◽  
A. G. Gojayev
Keyword(s):  
Oil And Gas ◽  
Gas Storage ◽  
Gas Condensate ◽  
Underground Gas Storage ◽  
Gas Reservoirs ◽  
Well Productivity ◽  
Reservoir Heterogeneity ◽  
Reservoir Development ◽  
Condensate Reservoir ◽  
Lithological Composition

Underground oil and gas reservoirs (formations) are characterized by spatial variability of their structure, material composition and petrophysical properties of its constituent rocks: particle size distribution, porosity, permeability, structure and texture of the pore space, carbonate content, electrical resistivity, oil and water saturation and other properties. When assessing development and exploitation conditions for underground gas storages, created in depleted underground oil and gas reservoirs, the inherited nature of the reservoir development should be taken into account. Therefore, identifying the features of variations in well productivity is a crucial task, solution of which can contribute to the creation of more efficient system for underground gas storage exploitation. The paper presents the findings of comparative analysis of spatial variations in well productivity during the exploitation of the Garadagh underground gas storage (Azerbaijan), created in the depleted gas condensate reservoir. An uneven nature of the variations in well productivity was established, which was connected with the reservoir heterogeneity (variations in the reservoir lithological composition and poroperm properties). The research was based on the analysis of spatial variations of a number of reservoir parameters: the reservoir net thickness, lithological composition and poroperm properties. The analysis of variations in the net thickness and poroperm properties of the VII horizon of the Garadagh gas condensate field was carried out based on the data of geophysical logging of about 40 wells and studying more than 90 core samples. The data on of more than 90 wells formed the basis for the spacial productivity variation analysis. The analysis of productivity variation in the space of well technological characteristics (based on data from 18 wells) in the Garadagh underground gas storage (UGS) was carried out through the example of the volume of cyclic gas injection and withdrawal in 2020–2021 season. The studies allowed revealing non-uniform spacial variations in the volumes of injected and withdrawn gas at the Garadagh UGS, created in the corresponding depleted gas condensate reservoir. The features of the UGS exploitation conditions are in good agreement with the features of the reservoir development conditions (variations in the well productivity). The inherited nature of the reservoir development and the underground gas storage exploitation is substantiated by the reservoir heterogeneity caused by the spatial variability of the reservoir lithological composition and poroperm properties. Assessing and taking into account the reservoir heterogeneity when designing underground gas storage exploitation conditions should be an important prerequisite for increasing UGS exploitation efficiency.

scholarly journals Experimental evaluation of compressibility coefficients for fractures and intergranular pores of an oil and gas reservoir

2021 ◽  
Vol 251 ◽  
pp. 658-666
Author(s):  
Vitaly Zhukov ◽  
Yuri Kuzmin
Keyword(s):  
Stress State ◽  
Oil And Gas ◽  
Pore Space ◽  
Total Porosity ◽  
Gas Reservoirs ◽  
Gas Reservoir ◽  
Intergranular Porosity ◽  
Hydrocarbon Fields ◽  
Oil And Gas Reservoir

The paper is devoted to studies of the volumetric response of rocks caused by changes in their stress state. Changes in the volume of fracture and intergranular components of the pore space based on measurements of the volume of pore fluid extruded from a rock sample with an increase in its  all-round compression have been experimentally obtained and analyzed.  Determination of the fracture and intergranular porosity components is based on the authors' earlier proposed method of their calculation using the values of longitudinal wave velocity and total porosity. The results of experimental and analytical studies of changes in porosity and its two components (intergranular and fractured) under the action of effective stresses are considered. This approach allowed the authors to estimate the magnitude  of the range of changes in the volumetric compressibility of both intergranular pores and fractures in a representative collection of 37 samples of the Vendian-age sand reservoir of the Chayanda field. The method of separate estimation of the compressibility coefficients of fractures and intergranular pores is proposed, their values and dependence on the effective pressure are experimentally obtained. It is determined that the knowledge of the values of fracture and intergranular porosity volumetric compressibility will increase the reliability of estimates of changes in petrophysical parameters of oil and gas reservoirs caused by changes in the stress state during the development of hydrocarbon fields.

JOINT IMPEDANCE INVERSION AND SPECTRAL DECOMPOSITION FOR DEEPWATER GAS RESERVOIR CHARACTERIZATION: A CASE STUDY IN SOUTH CHINA SEA

2020 ◽  
pp. 1-74
Author(s):  
Yaneng Luo ◽  
Mengqi Jiang ◽  
Kun Xiang ◽  
Yadi Yang ◽  
Handong Huang
Keyword(s):  
Spatial Distribution ◽  
Acoustic Impedance ◽  
Spectral Decomposition ◽  
Reservoir Characterization ◽  
Well Log ◽  
Gas Reservoirs ◽  
Gas Reservoir ◽  
Absorption Effect ◽  
Impedance Inversion ◽  
Gas Bearing

Gas reservoir characterization is one of the frontiers in seismic exploration. Acoustic impedance, one of the most effective seismic attributes, aims to describe the spatial distribution of rock properties. However, using acoustic impedance only is insufficient to describe gas-bearing layers accurately, in the case of rapid lithologic changes and complex geology in the deepwater area. The reflection seismograms show an absorption effect when seismic waves propagate through gas-bearing layers. The absorption effect can be used as an additional attribute to help gas reservoir characterization. Therefore, a new attribute is proposed for gas reservoir characterization in this study, which integrates the results of acoustic impedance and absorption coefficient. We estimate the acoustic impedance model by employing poststack impedance inversion and then we calculate probability distribution functions. Functions are classified into gas-bearing and non-gas layers. We discuss an absorption coefficient and obtain it from the spectrum gradient, where the gradient is calculated by spectral decomposition using the matching pursuit method. We apply the new attribute to characterize the spatial distribution and thickness of deepwater gas reservoirs in the Pearl River Mouth Basin. Well-log and geologic information show that the study area has an enrichment of gas reservoirs. Field data application shows the explicit distribution of the gas reservoir and in accordance with the well-log information, which indicates that the proposed attribute can improve gas reservoir characterization.

scholarly journals Experimental Study on Enhanced Condensate Recovery by Gas Injection in Yaha Condensate Gas Reservoir

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Yiming Wu ◽  
Kun Yao ◽  
Yan Liu ◽  
Xiangyun Li ◽  
Mimi Wu ◽  
...  
Keyword(s):  
Oil Recovery ◽  
Recovery Rate ◽  
Oil And Gas ◽  
Gas Injection ◽  
Recovery Factor ◽  
Co2 Injection ◽  
Gas Reservoirs ◽  
Gas Reservoir ◽  
Injection Method ◽  
Production Ratio

A condensate gas reservoir is an important special oil and gas reservoir between oil reservoir and natural gas reservoir. Gas injection production is the most commonly used development method for this type of gas reservoir, but serious retrograde condensation usually occurs in the later stages of development. To improve the recovery efficiency of condensate oil in the middle and late stages of production of a condensate gas reservoir, a gas injection parameter optimization test study was carried out, taking the Yaha gas condensate reservoir in China as an example. On the premise that the physical experimental model and key parameters met the actual conditions of the formation, the injection method, injection medium, injection-production ratio, and other parameters of the condensate gas reservoir were studied. Research on the injection method showed that the top injection method had a lower gas-oil ratio and higher condensate oil recovery. The study of injection medium showed that the production effect of carbon dioxide (CO2) injection was the best injection medium, and the maximum recovery rate of condensate oil was 95.11%. The injection-production ratio study showed that the injection-production ratio was approximately inversely proportional to the recovery factor of condensate gas and approximately proportional to the recovery factor of condensate oil. When the injection-production ratio was 1 : 1, the maximum recovery rate of condensate oil was 83.31%. In summary, in the later stage of gas injection development of the Yaha condensate gas reservoir, it was recommended to choose the development plan of CO2 injection at the top position with an injection-production ratio of 1 : 1. This research can not only provide guidance for the later formulation of gas injection plans for Yaha condensate gas reservoirs but also lay a foundation for the research of gas injection migration characteristics of other condensate gas reservoirs.

scholarly journals What’s Conventional and what’s Special in a Reservoir Study for Underground Gas Storage

2018 ◽  
Author(s):  
Francesca Verga
Keyword(s):  
Oil And Gas ◽  
Methodological Approach ◽  
Gas Storage ◽  
Reservoir Engineering ◽  
Underground Gas Storage ◽  
Gas Reservoirs ◽  
Gas Reservoir ◽  
Oil And Gas Reservoirs ◽  
Oil And Gas Reservoir

The development of an underground gas storage (UGS) project and its subsequent management must ensure technical feasibility, commercial value and long-term efficiency. The UGS industry has borrowed much of its knowledge from other disciplines (primarily oil and gas reservoir engineering), but it has also developed its own technology. This paper provides a methodological approach based on current practices and available methods for designing and safely operating a UGS (including the so-called “delta-pressure” option to enhance UGS performance) and highlights what is special in UGS compared to oil and gas reservoirs.

scholarly journals Representative permeability types and their application in researching upper Oligocene sedimentary oil reservoir of ThT oil field

2015 ◽  
Vol 18 (2) ◽  
pp. 46-58
Author(s):  
Thuan Van Tran
Keyword(s):  
Oil And Gas ◽  
Gas Permeability ◽  
Oil Field ◽  
Oil Reservoir ◽  
Gas Reservoir ◽  
Oil And Gas Fields ◽  
Upper Oligocene ◽  
Gas Fields ◽  
Oil And Gas Reservoir

Permeability is the indispensable parameter in oil and gas reservoir studies. In fact of researching and operating on oil and gas fields worldwide, there are many types of permeability. Each permeability type has a specific characteristic according to the study purpose. In this article, the specific characteristics of some typical permeability as gas permeability; water permeability, effective permeability; relative permeability … will be analyzed, especially concern to the role of each permeability type in oil reservoir study to assisting researchers has an overview to orient their study.

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