Gas/Oil Reservoir Pressure Maintenance by Way of Gas Injection (Russian)

2008 ◽  
Author(s):  
A.S. Romanov ◽  
E.F. Zolnikova
Keyword(s):  
Gas Injection ◽  
Oil Reservoir ◽  
Reservoir Pressure ◽  
Gas Oil

The Gas–Oil Interfacial Behavior during Gas Injection into an Asphaltenic Oil Reservoir

2013 ◽  
Vol 58 (9) ◽  
pp. 2513-2526 ◽  
Author(s):  
Mehdi Escrochi ◽  
Nasir Mehranbod ◽  
Shahab Ayatollahi
Keyword(s):  
Gas Injection ◽  
Oil Reservoir ◽  
Gas Oil ◽  
Interfacial Behavior

scholarly journals Modeling Near-Miscible Gas Foam Injection in Fractured Tight Rocks and Its Challenges

Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1998
Author(s):  
Haishan Luo ◽  
Kishore K. Mohanty
Keyword(s):  
Oil Recovery ◽  
Fractured Rock ◽  
Gas Injection ◽  
Gas Composition ◽  
Gas Oil ◽  
Rock Matrix ◽  
Reducing Gas ◽  
Tight Reservoirs ◽  
Modeling Strategy ◽  
Tight Rocks

Unlocking oil from tight reservoirs remains a challenging task, as the existence of fractures and oil-wet rock surfaces tends to make the recovery uneconomic. Injecting a gas in the form of a foam is considered a feasible technique in such reservoirs for providing conformance control and reducing gas-oil interfacial tension (IFT) that allows the injected fluids to enter the rock matrix. This paper presents a modeling strategy that aims to understand the behavior of near-miscible foam injection and to find the optimal strategy to oil recovery depending on the reservoir pressure and gas availability. Corefloods with foam injection following gas injection into a fractured rock were simulated and history matched using a compositional commercial simulator. The simulation results agreed with the experimental data with respect to both oil recovery and pressure gradient during both injection schedules. Additional simulations were carried out by increasing the foam strength and changing the injected gas composition. It was found that increasing foam strength or the proportion of ethane could boost oil production rate significantly. When injected gas gets miscible or near miscible, the foam model would face serious challenges, as gas and oil phases could not be distinguished by the simulator, while they have essentially different effects on the presence and strength of foam in terms of modeling. We provide in-depth thoughts and discussions on potential ways to improve current foam models to account for miscible and near-miscible conditions.

Evaluation method for energy parameters and energy saving potential of oil reservoir pressure maintenance pumps operating beyond permissible limits

2021 ◽  
Vol 6 ◽  
pp. 35-38
Author(s):  
Rashid Kafiatullin
Keyword(s):  
Energy Saving ◽  
Evaluation Method ◽  
Evaluation Methodology ◽  
Design Parameters ◽  
Oil Reservoir ◽  
Reservoir Pressure ◽  
Original Design ◽  
Energy Parameters ◽  
Energy Saving Potential ◽  
Basic Parameters

Oil reservoir pressure maintenance pumps are often pushed to operate significantly outside of their original design parameters. This can cause operating problems which impact their reliability and efficiency. The author offers the evaluation methodology for energy parameters and energy saving potential of oil reservoir pressure maintenance pumps in order to develop major pump parameters like efficiency, pressure, and specific electric power. The methodology was tested on 42 pump units. The values of variations of basic parameters indicate the energy saving potential of pump units.

scholarly journals Experimental Investigation of Oil Recovery from Tight Sandstone Oil Reservoirs by Pressure Depletion

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2667 ◽  
Author(s):  
Wenxiang Chen ◽  
Zubo Zhang ◽  
Qingjie Liu ◽  
Xu Chen ◽  
Prince Opoku Appau ◽  
...  
Keyword(s):  
Oil Recovery ◽  
Oil Reservoirs ◽  
Oil Reservoir ◽  
Reservoir Pressure ◽  
Dissolved Gas ◽  
Tight Sandstone ◽  
Bubble Point ◽  
Bubble Point Pressure ◽  
Pressure Depletion ◽  
Point Pressure

Oil production by natural energy of the reservoir is usually the first choice for oil reservoir development. Conversely, to effectively develop tight oil reservoir is challenging due to its ultra-low formation permeability. A novel platform for experimental investigation of oil recovery from tight sandstone oil reservoirs by pressure depletion has been proposed in this paper. A series of experiments were conducted to evaluate the effects of pressure depletion degree, pressure depletion rate, reservoir temperature, overburden pressure, formation pressure coefficient and crude oil properties on oil recovery by reservoir pressure depletion. In addition, the characteristics of pressure propagation during the reservoir depletion process were monitored and studied. The experimental results showed that oil recovery factor positively correlated with pressure depletion degree when reservoir pressure was above the bubble point pressure. Moreover, equal pressure depletion degree led to the same oil recovery factor regardless of different pressure depletion rate. However, it was noticed that faster pressure drop resulted in a higher oil recovery rate. For oil reservoir without dissolved gas (dead oil), oil recovery was 2–3% due to the limited reservoir natural energy. In contrast, depletion from live oil reservoir resulted in an increased recovery rate ranging from 11% to 18% due to the presence of dissolved gas. This is attributed to the fact that when reservoir pressure drops below the bubble point pressure, the dissolved gas expands and pushes the oil out of the rock pore spaces which significantly improves the oil recovery. From the pressure propagation curve, the reason for improved oil recovery is that when the reservoir pressure is lower than the bubble point pressure, the dissolved gas constantly separates and provides additional pressure gradient to displace oil. The present study will help engineers to have a better understanding of the drive mechanisms and influencing factors that affect development of tight oil reservoirs, especially for predicting oil recovery by reservoir pressure depletion.

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.

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 An evaluation on mechanisms of miscibility development in acid gas injection for volatile oil reservoirs

2019 ◽  
Vol 74 ◽  
pp. 59 ◽  
Author(s):  
Erhui Luo ◽  
Zifei Fan ◽  
Yongle Hu ◽  
Lun Zhao ◽  
Jianjun Wang
Keyword(s):  
Oil Recovery ◽  
Gas Injection ◽  
Simulation Method ◽  
Carbonate Reservoir ◽  
Gas Oil ◽  
Oil Composition ◽  
Acid Gas ◽  
Compositional Model ◽  
Injection Process ◽  
Acid Gas Injection

Produced gas containing the acid gas reinjection is one of the effective enhanced oil recovery methods, not only saving costs of disposing acid gases and zero discharge of greenhouse gases but also supporting reservoir pressure. The subsurface fluid from the Carboniferous carbonate reservoir in the southern margin of the Pre-Caspian basin in Central Asia has low density, low viscosity, high concentrations of H2S (15%) and CO2 (4%), high solution gas/oil ratio. The reservoir is lack of fresh water because of being far away onshore. Pilot test has already been implemented for the acid gas reinjection. Firstly, in our work a scheme of crude oil composition grouping with 15 compositions was presented on the basis of bottomhole sampling from DSTs of four wells. After matching PVT physical experiments including viscosity, density and gas/oil ratio and pressure–temperature (P–T) phase diagram by tuning critical properties of highly uncertain heavy components, the compositional model with phase behavior was built under meeting accuracy of phase fitting, which was used to evaluate mechanism of miscibility development in the acid gas injection process. Then using a cell-to-cell simulation method, vaporizing and/or condensing gas drive mechanisms were investigated for mixtures consisting of various proportions of CH4, CO2 and H2S in the gas injection process. Moreover, effects of gas compositions on miscible mechanisms have also been determined. With the aid of pressure-composition diagrams and pseudoternary diagrams generated from the Equation of State (EoS), pressures of First Contact Miscibility (FCM) and Multiple Contact Miscibility (MCM) for various gases mixing with the reservoir oil sample under reservoir temperature were calculated. Simulation results show that pressures of FCM are higher than those of MCM, and CO2 and H2S are able to reduce the miscible pressure. At the same time, H2S is stronger. As the CH4 content increases, both pressures of FCM and MCM are higher. But incremental values of MCM decrease. In addition, calculated envelopes of pseudoternary diagrams for mixtures of CH4, CO2 and H2S gases of varying composition with acid gas injection have features of bell shape, hourglass shape and triangle shape, which can be used to identify vaporizing and/or condensing gas drives. Finally, comparison of the real produced gas and the one deprived of its C3+ was performed to determine types of miscibility and calculate pressures of FCM and MCM. This study provides a theoretical guideline for selection of injection gas to improve miscibility and oil recovery.

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