scholarly journals An integrated heat efficiency model for superheated steam injection in heavy oil reservoirs

2019 ◽  
Vol 74 ◽  
pp. 7 ◽  
Author(s):  
Congge He ◽  
Anzhu Xu ◽  
Zifei Fan ◽  
Lun Zhao ◽  
Angang Zhang ◽  
...  
Keyword(s):  
Heavy Oil ◽  
Superheated Steam ◽  
Steam Injection ◽  
Injection Rate ◽  
Total Heat ◽  
Oil Reservoirs ◽  
Injection Time ◽  
New Model ◽  
Heat Efficiency ◽  
Heavy Oil Reservoirs

Accurate calculation of heat efficiency in the process of superheated steam injection is important for the efficient development of heavy oil reservoirs. In this paper, an integrated analytical model for wellbore heat efficiency, reservoir heat efficiency and total heat efficiency was proposed based on energy conservation principle. Comparisons have been made between the new model results, measured data and Computer Modelling Group (CMG) results for a specific heavy oil reservoir developed by superheated steam injection, and similarity is observed, which verifies the correctness of the new model. After the new model is validated, the effect of injection rate and reservoir thickness on wellbore heat efficiency and reservoir heat efficiency are analyzed. The results show that the wellbore heat efficiency increases with injection time. The larger the injection rate is, the higher the wellbore heat efficiency. However, the reservoir heat efficiency decreases with injection time and the injection rate has little impact on it. The reservoir thickness has no effect on wellbore heat efficiency, but the reservoir heat efficiency and total heat efficiency increase with the reservoir thickness rising.

A Study on Effect Evaluating and Parameters Sensitivity Analyzing of Superheated Steam Soak in Heavy Oil Reservoirs

2011 ◽  
Vol 239-242 ◽  
pp. 3069-3073 ◽  
Author(s):  
Qiang Zheng ◽  
Hui Qing Liu ◽  
Zhan Xi Pang ◽  
Fang Li
Keyword(s):  
Heavy Oil ◽  
Superheated Steam ◽  
Oil Production ◽  
Steam Injection ◽  
Injection Rate ◽  
Oil Reservoirs ◽  
Saturated Steam ◽  
Production Volume ◽  
Heavy Oil Reservoirs ◽  
Recovery Percentage

By using the technology of numerical reservoir simulation, we have compared superheated steam soak with saturated steam soak in area of heating, effect of distillation, capability of increasing oil production, volume of steam in need to evaluate the effect of superheated steam soak in heavy oil reservoirs. Analyzed the sensitivity of parameters like steam injection intensity, steam injection rate, soak time, degree of superheat to conclude the rule that they affect on recovery percentage. The research shows that, heating radius of superheated steam is greater than that of saturated steam, distillation effect of superheated steam is better than that of saturated steam, oil production of superheated steam is more than that of saturated steam, steam volume in need of superheated steam is less than that of saturated steam. Recovery percentage of superheated steam soak increases but more and more slowly with the increase in steam injection intensity, increases first and then decreases with the increase in steam injection rate, increases first and then decreases with the increase in soak time, increases but more and more slowly with the increase in degree of superheat. Influence of steam injection intensity is obvious to recovery percentage, but influence of other factors like soak time, steam injection rate, degree of superheat is insignificant.

scholarly journals Thermal Hydraulic Analysis Using GIS on Application of HTR to Thermal Recovery of Heavy Oil Reservoirs

2012 ◽  
Vol 2012 ◽  
pp. 1-15
Author(s):  
Yangping Zhou ◽  
Fu Li ◽  
Zhiwei Zhou ◽  
Yuanle Ma
Keyword(s):  
Heavy Oil ◽  
Superheated Steam ◽  
Steam Injection ◽  
Thermal Recovery ◽  
Oil Field ◽  
Oil Reservoirs ◽  
Hydraulic Analysis ◽  
Heavy Oil Reservoirs ◽  
Large Water ◽  
Thermal Hydraulic Analysis

At present, large water demand and carbon dioxide (CO2) emissions have emerged as challenges of steam injection for oil thermal recovery. This paper proposed a strategy of superheated steam injection by the high-temperature gas-cooled reactor (HTR) for thermal recovery of heavy oil, which has less demand of water and emission of CO2. The paper outlines the problems of conventional steam injection and addresses the advantages of superheated steam injection by HTR from the aspects of technology, economy, and environment. A Geographic Information System (GIS) embedded with a thermal hydraulic analysis function is designed and developed to analyze the strategy, which can make the analysis work more practical and credible. Thermal hydraulic analysis using this GIS is carried out by applying this strategy to a reference heavy oil field. Two kinds of injection are considered and compared: wet steam injection by conventional boilers and superheated steam injection by HTR. The heat loss, pressure drop, and possible phase transformation are calculated and analyzed when the steam flows through the pipeline and well tube and is finally injected into the oil reservoir. The result shows that the superheated steam injection from HTR is applicable and promising for thermal recovery of heavy oil reservoirs.

A New High-Temperature Gel for Profile Control in Heavy Oil Reservoirs

2015 ◽  
Vol 138 (2) ◽  
Author(s):  
Changjiu Wang ◽  
Huiqing Liu ◽  
Qiang Zheng ◽  
Yongge Liu ◽  
Xiaohu Dong ◽  
...  
Keyword(s):  
High Temperature ◽  
Oil Recovery ◽  
Heavy Oil ◽  
Three Dimensional ◽  
Heat Stability ◽  
Steam Injection ◽  
Oil Reservoirs ◽  
Steam Flooding ◽  
Profile Control ◽  
Heavy Oil Reservoirs

Controlling the phenomenon of steam channeling is a major challenge in enhancing oil recovery of heavy oil reservoirs developed by steam injection, and the profile control with gel is an effective method to solve this problem. The use of conventional gel in water flooding reservoirs also has poor heat stability, so this paper proposes a new high-temperature gel (HTG) plugging agent on the basis of a laboratory experimental investigation. The HTG is prepared with nonionic filler and unsaturated amide monomer (AM) by graft polymerization and crosslinking, and the optimal gel formula, which has strong gelling strength and controllable gelation time, is obtained by the optimization of the concentration of main agent, AM/FT ratio, crosslinker, and initiator. To test the adaptability of the new HTG to heavy oil reservoirs and the performance of plugging steam channeling path and enhancing oil recovery, performance evaluation experiments and three-dimensional steam flooding and gel profile control experiments are conducted. The performance evaluation experiments indicate that the HTG has strong salt resistance and heat stability and still maintains strong gelling strength after 72 hrs at 200 °C. The singular sand-pack flooding experiments suggest that the HTG has good injectability, which can ensure the on-site construction safety. Moreover, the HTG has a high plugging pressure and washing out resistance to the high-temperature steam after gel forming and keeps the plugging ratio above 99.8% when the following steam injected volume reaches 10 PV after gel breakthrough. The three-dimensional steam flooding and gel profile control experiments results show that the HTG has good plugging performance in the steam channeling path and effectively controls its expanding. This forces the following steam, which is the steam injected after the gelling of HTG in the model, to flow through the steam unswept area, which improves the steam injection profile. During the gel profile control period, the cumulative oil production increases by 294.4 ml and the oil recovery is enhanced by 8.4%. Thus, this new HTG has a good effect in improving the steam injection profile and enhancing oil recovery and can be used to control the steam channeling in 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.

scholarly journals Experimental study on the mechanism and development effect of multi-gas assisted steam huff and puff process in the offshore heavy oil reservoirs

2021 ◽  
Author(s):  
Jie Fan ◽  
Zuqing He ◽  
Wei Pang ◽  
Daoming Fu ◽  
Hanxiu Peng ◽  
...  
Keyword(s):  
Heavy Oil ◽  
Steam Injection ◽  
Thermal Recovery ◽  
Oil Reservoirs ◽  
Viscosity Reduction ◽  
Oil Viscosity ◽  
Enhanced Production ◽  
Heavy Oil Reservoirs ◽  
Water Gas ◽  
Development Mechanism

AbstractMulti-gas assisted steam huff and puff process is a relatively new thermal recovery technology for offshore heavy oil reservoirs. Some blocks of Bohai oilfield have implemented multi-gas assisted steam huff and puff process. However, the development mechanism still requires further study. In this paper, high-temperature high-pressure (HTHP) PVT experiments and different huff and puff experiments of sand pack were carried out to reveal the enhanced production mechanism and evaluate the development effect of multi-gas assisted steam huff and puff process. The results indicated that viscosity reduction and thermal expansion still were the main development mechanism of multi-gas assisted steam huff and puff process. Specifically, CO2 easily dissolved in the heavy oil that made it mainly play the role of reducing oil viscosity, N2 was characteristics of small solubility and good expansibility, and it could improve formation pressure, increase steam sweep volume and even reduce the heat loss. Meanwhile, injecting multi-gas and steam could break the balance of heavy oil component that made the content of resin reduce and the content of saturates, aromatics and asphaltene increase so as to further reduce the viscosity of heavy oil. Compared with steam huff and puff process, multi-gas assisted steam huff and puff process increased the recovery by 2–5%. The optimal water–gas ratio and steam injection temperature were 4:6 and 300℃, respectively. The results suggested that multi-gas assisted steam huff and puff process would have wide application prospect for offshore heavy oil reservoirs.

Variation Characteristics of Reservoir Physical Properties after Thermal Recovery in Heavy Oil Reservoirs

2012 ◽  
Vol 550-553 ◽  
pp. 2848-2852
Author(s):  
Xiao Hu Dong ◽  
Hui Qing Liu ◽  
Zhan Xi Pang ◽  
Yong Gang Yi
Keyword(s):  
Physical Properties ◽  
Heavy Oil ◽  
Steam Injection ◽  
Thermal Recovery ◽  
Oil Reservoirs ◽  
Sand Production ◽  
Heavy Oil Reservoirs ◽  
Variation Characteristics ◽  
Porosity And Permeability ◽  
Production Period

With the development of heavy oil reservoirs, it faced a series of problems. Using the theory of thermal-hydrological-mechanical (THM) coupling, a predictive model of reservoir physical properties (RPP) after thermal recovery is established. Based on this model, the changing process of reservoir physical properties is simulated by the method of numerical simulation. The obtained results show that the sand production has a significant influence on RPP. By contrast with rock deformation, it has a smaller influence on RPP. The influence caused by the former is about 5~8 times than latter. During the period of steam injection, resulting from the movement of sand grain and expansion of reservoir, both porosity and permeability of reservoir are on the rise. Due to the sand production and reservoir compression, a reducing tendency is happened in the production period. The changes of RPP in reservoir are huge along the main streamline direction, and it might change because of the presence of high-permeability path.

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