scholarly journals Study of Displacement Characteristics of Fire Flooding in Different Viscosity Heavy Oil Reservoirs

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Bingyan Liu ◽  
Jinzhong Liang ◽  
Fang Zhao ◽  
Tong Liu ◽  
Zongyao Qi ◽  
...  
Keyword(s):  
Heavy Oil ◽  
Early Stage ◽  
Injection Pressure ◽  
High Viscosity ◽  
Production Performance ◽  
Air Injection ◽  
Oil Reservoirs ◽  
Stable Combustion ◽  
Heavy Oil Reservoirs ◽  
Water Cut

A field test in the Xinjiang oilfield in China shows that the viscosity of heavy oil has a certain influence on the combustion dynamics and injection-production performance of fire flooding. The experiment in this study uses a one-dimensional combustion tube to study the temperature, gas composition, and air injection pressure and the production performance of the fire flooding of heavy oil with different viscosities. The results show that the oil viscosities of 1180–22500 mPa·s can achieve stable combustion, and the O2 content of the gas produced during the stable combustion stage is <0.5%. The higher the viscosity of the heavy oil, the higher the temperature in the burned zone and the smaller the range of the temperature increase in the unburned zone. The air injection pressure will increase rapidly until a stable seepage channel is formed, and then, it will drop to a level close to the formation pressure. High-viscosity heavy oil requires a higher air injection pressure and will remain in the high-pressure stage for a longer period of time. Low-viscosity heavy oil has a low water cut in the early stage of fire flooding, a large oil production rate, and a low and stable air–oil ratio. The water cut of high-viscosity heavy oil increases rapidly in the early stage of fire flooding and then decreases gradually, so a good air–oil ratio can only be obtained in the middle and late stages of fire flooding. Thus, fire flooding may be more suitable for application in common heavy oil and some extra heavy oil reservoirs with lower viscosities.

Multilateral Wells to Improve Production Performance in Heavy Oil Reservoirs: The Challenges of the ZAM-408ML Well

2008 ◽  
Author(s):  
Loris Tealdi ◽  
Maurizio Rampoldi ◽  
Henri Malonga ◽  
Leone Riccobon ◽  
Fabrice Okassa ◽  
...  
Keyword(s):  
Heavy Oil ◽  
Production Performance ◽  
Oil Reservoirs ◽  
Improve Production ◽  
Heavy Oil Reservoirs

scholarly journals Mechanisms on the Injection Conformance Reversion during Polymer Flooding of Offshore Heterogeneous Heavy-Oil Reservoirs

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Zhijie Wei ◽  
Xiaodong Kang ◽  
Yuyang Liu ◽  
Hanxu Yang
Keyword(s):  
Polymer Solution ◽  
Heavy Oil ◽  
Flow Resistance ◽  
Polymer Flooding ◽  
Production Performance ◽  
Oil Reservoirs ◽  
Resistance Force ◽  
Oil Viscosity ◽  
Permeable Layer ◽  
Heavy Oil Reservoirs

Injection conformance reversion commonly observed during polymer flooding in offshore heterogeneous heavy-oil reservoirs weakens the volumetric sweep of polymer solution and compromises its EOR results. To investigate its mechanisms and impact factors, one mathematical model to predicate injection conformance behavior is constructed for heterogeneous reservoirs based on the Buckley-Leverett function. The different suction capability of each layer to polymer solution results in distinct change law of the flow resistance force, which in turn reacts upon the suction capability and creates dynamic redistribution of injection between layers. Conformance reversion takes place when the variation ratio of flow resistance force of different layers tends to be the same. The peak value and scope of conformance reversion decrease and reversion timing is advanced as oil viscosity or permeability contrast increases, or polymer concentration or relative thickness of low permeable layer decreases, which compromises the ability of polymer flooding to improve the volumetric sweep and lower suction of the low permeable layer. The features of offshore polymer flooding tend to make the injection conformance V-type and create low-efficiency circulation of polymer in a high permeable layer more easily. These results can provide guidance to improve the production performance of polymer flooding in offshore heterogeneous heavy-oil reservoirs.

Improved production performance of heavy oil reservoirs with compacted and shaled-out interlayers

2021 ◽  
pp. 28-31
Author(s):  
А.Т. Zaripov ◽  
◽  
А.R. Razumov ◽  
Аnt.N. Beregovoy ◽  
N.А. Knyazeva ◽  
...  
Keyword(s):  
Heavy Oil ◽  
Production Performance ◽  
Oil Reservoirs ◽  
Heavy Oil Reservoirs

Pressure Maintenance and Improving Oil Recovery by Means of Immiscible Water-Alternating-CO2 Processes in Thin Heavy-Oil Reservoirs

2013 ◽  
Vol 16 (01) ◽  
pp. 60-71 ◽  
Author(s):  
Sixu Zheng ◽  
Daoyong Yang
Keyword(s):  
Oil Recovery ◽  
Heavy Oil ◽  
Oil Production ◽  
Horizontal Wells ◽  
Operating Conditions ◽  
Oil Reservoirs ◽  
Oil Saturation ◽  
Water Alternating Gas ◽  
Heavy Oil Reservoirs ◽  
Water Cut

Summary Techniques have been developed to experimentally and numerically evaluate performance of water-alternating-CO2 processes in thin heavy-oil reservoirs for pressure maintenance and improving oil recovery. Experimentally, a 3D physical model consisting of three horizontal wells and five vertical wells is used to evaluate the performance of water-alternating-CO2 processes. Two well configurations have been designed to examine their effects on heavy-oil recovery. The corresponding initial oil saturation, oil-production rate, water cut, oil recovery, and residual-oil-saturation (ROS) distribution are examined under various operating conditions. Subsequently, numerical simulation is performed to match the experimental measurements and optimize the operating parameters (e.g., slug size and water/CO2 ratio). The incremental oil recoveries of 12.4 and 8.9% through three water-alternating-CO2 cycles are experimentally achieved for the aforementioned two well configurations, respectively. The excellent agreement between the measured and simulated cumulative oil production indicates that the displacement mechanisms governing water-alternating-CO2 processes have been numerically simulated and matched. It has been shown that water-alternating-CO2 processes implemented with horizontal wells can be optimized to significantly improve performance of pressure maintenance and oil recovery in thin heavy-oil reservoirs. Although well configuration imposes a dominant impact on oil recovery, the water-alternating-gas (WAG) ratios of 0.75 and 1.00 are found to be the optimum values for Scenarios 1 and 2, respectively.

Air Injection Recovery of Cold-Produced Heavy Oil Reservoirs

2001 ◽  
Author(s):  
K.A. Miller ◽  
R.G. Moore ◽  
M.G. Ursenbach ◽  
C.J. Laureshen ◽  
S.A. Mehta
Keyword(s):  
Heavy Oil ◽  
Air Injection ◽  
Oil Reservoirs ◽  
Heavy Oil Reservoirs

scholarly journals Comparison of Foamy Oil Behaviour between Shallow and Middepth Heavy Oil Reservoirs in the Orinoco Belt

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Xingmin Li ◽  
Changchun Chen ◽  
Zhangcong Liu ◽  
Yongbin Wu ◽  
Xiaoxing Shi
Keyword(s):  
Heavy Oil ◽  
Oil And Gas ◽  
Production Performance ◽  
Oil Reservoirs ◽  
Recovery Factor ◽  
Oil Reservoir ◽  
Foamy Oil ◽  
Heavy Oil Reservoirs ◽  
Heavy Oil Reservoir ◽  
The Difference

Nowadays, extra heavy oil reservoirs in the Orinoco Heavy-Oil-Belt in Venezuela are exploited via cold production process, which present different production performance in well productivity and primary recovery factor. The purpose of this study is to investigate the causes for such differences with the aspect of foamy oil mechanism. Two typical oil samples were adopted from a shallow reservoir in western Junìn region and a middepth reservoir in eastern Carabobo region in the Belt, respectively. A depletion test was conducted using 1D sand-pack with a visualized microscopic flow observation installation for each of the oil samples under simulated reservoir conditions. The production performance, the foamy oil behaviour, and the oil and gas morphology were recorded in real time during the tests. The results indicated that the shallow heavy oil reservoir in the Belt presents a weaker foamy oil phenomenon when compared with the middepth one; its foamy oil behaviour lasts a shorter duration with a smaller scope, with bigger bubble size and less bubble density. The difference in foamy oil behaviour for those two types of heavy oil reservoir is caused by the difference in reservoir pressure, solution GOR, asphaltene content, etc. Cold production presents obvious features of three stages under the action of strong foamy oil displacement mechanism for the middepth heavy oil reservoir, which could achieve a more favourable production performance. In the contrary, no such obvious production characteristics for the shallow heavy oil reservoir are observed due to weaker foamy oil behaviour, and its primary recovery factor is 9.38 percent point lower than which of the middle heavy oil reservoirs.

Development Features of Cold Production with Horizontal Wells in a Foamy Extra-Heavy Oil Reservoir

2021 ◽  
Author(s):  
Zhaopeng Yang ◽  
Xingmin Li ◽  
Xinxia Xu ◽  
Yang Shen ◽  
Xiaoxing Shi
Keyword(s):  
Heavy Oil ◽  
Horizontal Wells ◽  
Oil Field ◽  
Production Performance ◽  
Oil Reservoirs ◽  
Bubble Point ◽  
Foamy Oil ◽  
Bubble Point Pressure ◽  
Heavy Oil Reservoirs ◽  
Point Pressure

Abstract The block M as a foamy extra-heavy oil field in the Carabobo Area, the eastern Orinoco Belt, has been exploited by foamy oil cold production utilizing horizontal wells. The early producing area of block M has been put into production more than 10 years. And the development features of cold production in foamy extra-heavy oil reservoirs are different from the conventional oil field. It is necessary to investigate the development features of this kind reservoir and analyze its influence factors. Combining the production data with the reservoir geological characteristics of the research area, the cold production features of foamy extra-heavy oil using horizontal wells are analyzed. Then numerical simulations were adopted to study the influence factors of cold production performance. In the early stage of cold production, the oil production rate is high and the producing GOR is low. With the process of cold production, the reservoir pressure decreases gradually, the producing GOR increases gradually, and the oil production rate decreases gradually. When the bottom hole flowing pressure drops to below the bubble point pressure, the flow of extra-heavy oil in the reservoir can be divided into two zones: far well zone and near well area. In the far well zone, the pressure is higher than the bubble point pressure. The flow of oil is a single-phase flow, and the displacement mode is elastic driving. In the near well area, the pressure is lower than the bubble point pressure, and the oil flow is foamy oil flow, and the displacement mode is the dissolving gas drive driven by foamy oil. There exists many factors that influence the cold production performance of foamy extra-heavy oil, including reservoir depth, reservoir thickness, reservoir physical property and heterogeneity. The oil recovery factor per unit pressure drop can evaluate the cold production performance of foamy extra-heavy oil reservoirs. The effectiveness of cold production is closely related to reservoir parameters. Larger reservoir thickness, deeper reservoir depth and greater reservoir permeability will enhance the performance of cold production. Closer, larger and more interlayers above the horizontal well will hinder the performance of cold production. This research provides certain guidance and reference for further development adjustment and new project evaluation for foamy extra-heavy oil reservoirs in the Eastern Orinoco Belt.

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