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.

Seismic characterization of heavy oil reservoir during thermal production: A case study

Geophysics ◽  
2017 ◽  
Vol 82 (1) ◽  
pp. B13-B27 ◽  
Author(s):  
Hemin Yuan ◽  
De-Hua Han ◽  
Weimin Zhang
Keyword(s):  
Heavy Oil ◽  
Rock Physics ◽  
Time Lapse ◽  
Steam Injection ◽  
Oil Reservoirs ◽  
Inversion Method ◽  
Oil Reservoir ◽  
Steam Chamber ◽  
Heavy Oil Reservoirs ◽  
Heavy Oil Reservoir

Heavy oil reservoirs are important alternative energy resources to conventional oil and gas reservoirs. However, due to the high viscosity, most production methods of heavy oil reservoirs involve thermal production. Heavy oil reservoirs’ properties change dramatically during thermal production because the viscosity drops drastically with increasing temperature. Moreover, the velocity and density also decrease after steam injection, leading to a longer traveltime of seismic velocities and low impedance of the steam chamber zone. These changes of properties can act as indicators of the steam chamber and can be detected through the time-lapse inversion method. We first establish the rock-physics relationship between oil sands’ impedance and temperature on the basis of our previous laboratory work. Then, we perform the forward modeling of the heavy oil reservoir with the steam chamber to demonstrate the influence of steam injection on seismic profiles. Then, we develop a modified-Cauchy prior-distribution-based time-lapse inversion method and perform a 2D model test. The inversion method is then applied on the real field data, and the results are analyzed. By combining the inverted impedance and rock-physics relation between impedance and temperature, the temperature distribution map is obtained, which can work as an indicator of steam chamber. Finally, an empirical relation between impedance and velocity is established, and velocity is derived from the impedance.

Study and Application of EOR on Conventional Heavy Oil Reservoir

2011 ◽  
Vol 236-238 ◽  
pp. 825-828
Author(s):  
Chuan Min Xiao
Keyword(s):  
Heavy Oil ◽  
Oil Reservoirs ◽  
Water Flooding ◽  
Oil Reservoir ◽  
Pilot Test ◽  
Gel Time ◽  
Heavy Oil Reservoirs ◽  
Output Ratio ◽  
Heavy Oil Reservoir ◽  
Displacement Adjustment Method

According to the characters of conventional heavy oil reservoir, liquid and exploitation progress, displacement adjustment method was applied to reduce degression and enhance recovery. The experiment results showed the gel time could be controlled and the strength could be adjusted. The flooding oil rate was more 14.3％ than water flooding in the lab. The pilot test showed that the test effect of moveable gel flooding was significantly good, the accumulated incremental oil production of 6 well groups is 54756t, input-output ratio is 1: 4.1, which shows satisfactory effects in improving the water flooding effect in this conventional 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.

Methods Study on Gas Channeling of In Situ Combustion Development in Developed Heavy Oil Reservoir

2013 ◽  
Vol 316-317 ◽  
pp. 834-837
Author(s):  
Zong Zhan Xue ◽  
Deng Fa He ◽  
Xiao Heng Wang
Keyword(s):  
Heavy Oil ◽  
Injection Rate ◽  
Oil Reservoirs ◽  
Oil Reservoir ◽  
Reservoir Properties ◽  
In Situ Combustion ◽  
Heavy Oil Reservoirs ◽  
Heavy Oil Reservoir ◽  
Gas Channeling

Now in situ combustion became one of the ways for the developed heavy oil reservoirs to convert development pattern and improve recovery. After long time steam huff and puff development in heavy oil reservoir, it was obvious that there was a big change on the oil zones and reservoir properties and the reservoir heterogeneity. When it was converted to in situ combustion, the injection gas often break through along the high permeability layers in the fire drive wells that make the sweep area smaller and decrease the reservoir recovery. By analysis on the gas channeling of in situ combustion occurred in the heavy oil reservoirs, the methods was put forward to develop heavy oil reservoir using in situ combustion reasonably including well space infilling, controlling the gas injection rate, adding roam surfactant agent and using fire drive with horizontal well assisted etc. to prevent the condition of gas channeling occurring. It will greatly improve the success and adaptability of the in situ combustion used in vertical wells of the heavy oil reservoir by using these methods. It also will build on basis of the heavy oil reservoir converted to in situ combustion development.

scholarly journals The Impact of Plane Heterogeneity on Steam Flooding Development in Heavy Oil Reservoirs

Lithosphere ◽  
2021 ◽  
Vol 2021 (Special 4) ◽  
Author(s):  
Yaguang Qu ◽  
YiPing Ye ◽  
Shichang Ju ◽  
Jiawen Liu ◽  
Meng Lei
Keyword(s):  
Heavy Oil ◽  
Oil Reservoirs ◽  
Oil Reservoir ◽  
Reservoir Heterogeneity ◽  
Steam Flooding ◽  
Sand Body ◽  
Well Pattern ◽  
Heavy Oil Reservoirs ◽  
Heavy Oil Reservoir ◽  
The Impact

Abstract Steam flooding is proven to be an effective method to improve the development effect of heavy oil reservoirs. And steam flooding is the most common oil recovery technology for heavy oil reservoirs in China. However, because of the various reservoir physical properties, bring great challenges to successful steam flooding development. According to the previous research and development practice, we know that reservoir heterogeneity has a great influence on the development effect of water flooding. Due to the heterogeneity of reservoirs, the development of different injection-production well patterns will be affected. However, it is uncertain whether reservoir heterogeneity has an impact on steam flooding development effect. In order to clarify the above scientific issues, we take Xinjiang steam flooding oilfield as the research object to carry out relevant research. According to the reservoir distribution characteristics of Xinjiang Oilfield, three conceptual heterogeneity models representing permeability, thickness, and geometric plane heterogeneity are firstly proposed. Then, mathematic models with different plane heterogeneity of reservoir sand were built. Based on the mathematic model, initial conditions, boundary condition, and geological parameters of conceptual models, different steam flooding patterns were studied by applying numerical calculation. It is found that heterogeneity is an important geological factor affecting the development of steam flooding of heavy oil reservoir. And the results showed that cumulative oil production was different of different flood pattern at the same production condition. It can be concluded that the development effect of steam flooding of heavy reservoirs is strongly influenced by flood pattern. In order to improve development effectiveness of steam flooding of heavy oil reservoirs, flood pattern should be optimized. For each type of plane heterogeneity reservoir, a reasonable flood pattern was proposed. For plane heterogeneity of permeability, thickness, and geometry form, under the conditions of that as the producer was deployed in high permeability, thick, wide sand body and injector was deployed in low permeability, thin, narrow sand body, the recovery of steam flooding in heavy oil reservoir was better. Finally, how the three types of plane heterogeneity influence steam flooding of heavy reservoirs was discussed by adopting a sensitivity analysis method. The results show that the influence of permeability heterogeneity is the largest, thickness heterogeneity is the second, and geometric heterogeneity is the least. This conclusion can help us improve the development of this reservoir. And also, the findings of this study can help for better understanding of properly deployed well pattern and how to effective develop the heavy oil reservoirs of strong plane heterogeneity for other heavy oil reservoirs.

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 Evaluation of the Vertical Producing Degree of Commingled Production via Waterflooding for Multilayer Offshore Heavy Oil Reservoirs

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2428 ◽  
Author(s):  
Fei Shen ◽  
Linsong Cheng ◽  
Qiang Sun ◽  
Shijun Huang
Keyword(s):  
Heavy Oil ◽  
Flow Model ◽  
Dynamic Method ◽  
Theoretical Models ◽  
Oil Reservoirs ◽  
Sweep Efficiency ◽  
One Dimensional ◽  
Heavy Oil Reservoirs ◽  
The Difference ◽  
Important Form

Recently, commingling production has been widely used for the development of offshore heavy oil reservoirs with multilayers. However, the differences between layers in terms of reservoir physical properties, oil properties and pressure have always resulted in interlayer interference, which makes it more difficult to evaluate the producing degree of commingled production. Based on the Buckley–Leverett theory, this paper presents two theoretical models, a one-dimensional linear flow model and a planar radial flow model, for water-flooded multilayer reservoirs. Through the models, this paper establishes a dynamic method to evaluate seepage resistance, sweep efficiency and recovery percent and then conducts an analysis with field data. The result indicates the following: (1) the dynamic difference in seepage resistance is an important form of interlayer interference during the commingled production of an offshore multilayer reservoir; (2) the difference between commingled production and separated production is small within a certain range of permeability ratio or viscosity ratio, but separated production should be adopted when the ratio exceeds a certain value.

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.

Experimental Analysis of the Effects of Varying Temperature and Viscosities on Foamy Oil Production

2021 ◽  
Author(s):  
Jasmine Shivani Medina ◽  
Iomi Dhanielle Medina ◽  
Gao Zhang
Keyword(s):  
Oil Recovery ◽  
Heavy Oil ◽  
Elevated Temperatures ◽  
Oil Production ◽  
Oil Reservoirs ◽  
Oil Viscosity ◽  
Gas Recovery ◽  
Foamy Oil ◽  
Heavy Oil Reservoirs ◽  
Pressure Depletion

Abstract The phenomenon of higher than expected production rates and recovery factors in heavy oil reservoirs captured the term "foamy oil," by researchers. This is mainly due to the bubble filled chocolate mousse appearance found at wellheads where this phenomenon occurs. Foamy oil flow is barely understood up to this day. Understanding why this unusual occurrence exists can aid in the transfer of principles to low recovery heavy oil reservoirs globally. This study focused mainly on how varying the viscosity and temperature via pressure depletion lab tests affected the performance of foamy oil production. Six different lab-scaled experiments were conducted, four with varying temperatures and two with varying viscosities. All experiments were conducted using lab-scaled sand pack pressure depletion tests with the same initial gas oil ratio (GOR). The first series of experiments with varying temperatures showed that the oil recovery was inversely proportional to elevated temperatures, however there was a directly proportional relationship between gas recovery and elevation in temperature. A unique observation was also made, during late-stage production, foamy oil recovery reappeared with temperatures in the 45-55°C range. With respect to the viscosities, a non-linear relationship existed, however there was an optimal region in which the live-oil viscosity and foamy oil production seem to be harmonious.

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