scholarly journals Time Scales for Steam Injection and Bitumen Production in Steam-Assisted Gravity Drainage

Energy ◽  
2021 ◽  
pp. 120430
Author(s):  
Jingyi Wang ◽  
Ian D. Gates
Keyword(s):  
Time Scales ◽  
Steam Injection ◽  
Gravity Drainage ◽  
Steam Assisted Gravity Drainage

Numerical Simulation of Thermal Solvent Replacing Steam under Steam Assisted Gravity Drainage SAGD Process

2010 ◽  
Author(s):  
Weiqiang Li ◽  
Daulat D. Mamora
Keyword(s):  
High Temperature ◽  
Oil Recovery ◽  
Oil Sands ◽  
Steam Injection ◽  
Thermal Recovery ◽  
Production Performance ◽  
Gravity Drainage ◽  
Steam Assisted Gravity Drainage ◽  
Recovery Technique ◽  
Simulation Results

Abstract Steam Assisted Gravity Drainage (SAGD) is one successful thermal recovery technique applied in the Athabasca oil sands in Canada to produce the very viscous bitumen. Water for SAGD is limited in supply and expensive to treat and to generate steam. Consequently, we conducted a study into injecting high-temperature solvent instead of steam to recover Athabasca oil. In this study, hexane (C6) coinjection at condensing condition is simulated using CMG STARS to analyze the drainage mechanism inside the vapor-solvent chamber. The production performance is compared with an equivalent steam injection case based on the same Athabasca reservoir condition. Simulation results show that C6 is vaporized and transported into the vapor-solvent chamber. At the condensing condition, high temperature C6 reduces the viscosity of the bitumen more efficiently than steam and can displace out all the original oil. The oil production rate with C6 injection is about 1.5 to 2 times that of steam injection with oil recovery factor of about 100% oil initially-in-place. Most of the injected C6 can be recycled from the reservoir and from the produced oil, thus significantly reduce the solvent cost. Results of our study indicate that high-temperature solvent injection appears feasible although further technical and economic evaluation of the process is required.

scholarly journals A steam rising model of steam-assisted gravity drainage production for heavy oil reservoirs

2019 ◽  
Vol 38 (4) ◽  
pp. 801-818
Author(s):  
Ren-Shi Nie ◽  
Yi-Min Wang ◽  
Yi-Li Kang ◽  
Yong-Lu Jia
Keyword(s):  
Production Rate ◽  
Horizontal Well ◽  
Oil Production ◽  
Steam Injection ◽  
Injection Rate ◽  
Gravity Drainage ◽  
Model Parameters ◽  
Steam Quality ◽  
Steam Chamber ◽  
Steam Assisted Gravity Drainage

The steam chamber rising process is an essential feature of steam-assisted gravity drainage. The development of a steam chamber and its production capabilities have been the focus of various studies. In this paper, a new analytical model is proposed that mimics the steam chamber development and predicts the oil production rate during the steam chamber rising stage. The steam chamber was assumed to have a circular geometry relative to a plane. The model includes determining the relation between the steam chamber development and the production capability. The daily oil production, steam oil ratio, and rising height of the steam chamber curves influenced by different model parameters were drawn. In addition, the curve sensitivities to different model parameters were thoroughly considered. The findings are as follows: The daily oil production increases with the steam injection rate, the steam quality, and the degree of utilization of a horizontal well. In addition, the steam oil ratio decreases with the steam quality and the degree of utilization of a horizontal well. Finally, the rising height of the steam chamber increases with the steam injection rate and steam quality, but decreases with the horizontal well length. The steam chamber rising rate, the location of the steam chamber interface, the rising time, and the daily oil production at a certain steam injection rate were also predicted. An example application showed that the proposed model is able to predict the oil production rate and describe the steam chamber development during the steam chamber rising stage.

scholarly journals A Separate-Phase Drag Model and a Surrogate Approximation for Simulation of the Steam-Assisted-Gravity-Drainage Process

SPE Journal ◽  
2016 ◽  
Vol 21 (02) ◽  
pp. 364-379 ◽  
Author(s):  
Juan C. Padrino ◽  
Xia Ma ◽  
W. Brian VanderHeyden ◽  
Duan Z. Zhang
Keyword(s):  
Multiphase Flow ◽  
Time Scales ◽  
Momentum Equation ◽  
Numerical Code ◽  
Gravity Drainage ◽  
Steam Assisted Gravity Drainage ◽  
Viscous Forces ◽  
Averaged Equations ◽  
Execution Speed ◽  
The Cost

Summary General, ensemble phase-averaged equations for multiphase flows were specialized for the simulation of the steam-assisted-gravity-drainage (SAGD) process. In the average momentum equation, fluid/solid and fluid/fluid viscous interactions are represented by separate force terms. This equation has a form similar to that of Darcy's law for multiphase flow but augmented by the fluid/fluid viscous forces. Models for these fluid/fluid interactions are suggested and implemented into the numerical code CartaBlanca. Numerical results indicate that the model captures the main features of the multiphase flow in the SAGD process, but the detailed features, such as plumes, are missed. We find that viscous coupling among the fluid phases is important. Advection time scales for the different fluids differ by several orders of magnitude because of vast viscosity differences. Numerically resolving all these time scales is time consuming. To address this problem, we introduce a steam-surrogate approximation to increase the steam-advection time scale, while keeping the mass and energy fluxes well-approximated. This approximation leads to approximately a 40-fold speedup in execution speed of the numerical calculations at the cost of a few percentage errors in the relevant quantities.

Development of a Thermal Wellbore Simulator With Focus on Improving Heat-Loss Calculations for Steam-Assisted-Gravity-Drainage Steam Injection

2016 ◽  
Vol 19 (02) ◽  
pp. 305-315 ◽  
Author(s):  
Wanqiang Xiong ◽  
Mehdi Bahonar ◽  
Zhangxin Chen
Keyword(s):  
Heat Loss ◽  
Steam Injection ◽  
Loss Estimation ◽  
Gravity Drainage ◽  
Thermal Processes ◽  
Injection Wells ◽  
Steam Assisted Gravity Drainage ◽  
Cfd Models ◽  
Fully Implicit ◽  
Loss Modeling

Summary Typical thermal processes involve sophisticated wellbore configurations, complex fluid flow, and heat transfer in tubing, annulus, wellbore completion, and surrounding formation. Despite notable advancements made in wellbore modeling, accurate heat-loss modeling is still a challenge by use of the existing wellbore simulators. This challenge becomes even greater when complex but common wellbore configurations, such as multiparallel or multiconcentric tubings, are used in thermal processes such as steam-assisted gravity drainage (SAGD). To improve heat-loss estimation, a standalone fully implicit thermal wellbore simulator is developed that can handle several different wellbore configurations and completions. This simulator uses a fully implicit method to model heat loss from tubing walls to the surrounding formation. Instead of implementing the common Ramey (1962) method for heat-loss calculations, which has been shown to be a source of large errors, a series of computational-fluid-dynamics (CFD) models are run for the buoyancy-driven flow for different annulus sizes and lengths and numbers of tubings. On the basis of these CFD models, correlations are derived that can conveniently be used for the more-accurate heat-loss estimation from the wellbore to the surrounding formation for SAGD injection wells with single or multiple tubing strings. These correlations are embedded in the developed wellbore simulator, and results are compared with other heat-loss-modeling methods to demonstrate its improvements. A series of validations against commercial simulators and field data are presented in this paper.

A Multistage Theoretical Model To Characterize the Liquid Level During Steam-Assisted-Gravity-Drainage Process

SPE Journal ◽  
2016 ◽  
Vol 22 (01) ◽  
pp. 327-338 ◽  
Author(s):  
Yang Yang ◽  
Shijun Huang ◽  
Yang Liu ◽  
Qianlan Song ◽  
Shaolei Wei ◽  
...  
Keyword(s):  
Dynamic Performance ◽  
Mass Conservation ◽  
Steam Injection ◽  
Injection Rate ◽  
Thermal Recovery ◽  
Liquid Level ◽  
Gravity Drainage ◽  
Steam Assisted Gravity Drainage ◽  
Performance Predictions ◽  
Close Distance

Summary The technology of steam-assisted gravity drainage (SAGD) with a dual horizontal well pair has been widely adopted in thermal recovery for heavy oil in recent years. However, the close distance between injector and producer makes it easy to cause steam breakthrough, which means lower thermal efficiency as well as higher investment. It is generally acknowledged that there is a vapor-liquid interface between the injector and producer. A suitable liquid level is desired to prevent steam from being produced directly; otherwise, an overly high liquid level would influence oil productivity or even submerge the injector. The existence of a liquid level generates a temperature difference (i.e., subcool) between two wells. Subcool has widely been used to characterize the liquid level in research, yet it is inaccurate. Further studies are still needed on how to maintain a suitable and stable liquid level in SAGD development. In addition to the heat-loss model and geometric features of the steam chamber (SC), mass conservation, energy conservation, and gravity-drainage theory are used to develop a multistage mathematical model for liquid-level characterization during the SAGD process. The new model is validated against both field data and simulation results. On the basis of this model, an optimal production/injection ratio (PIR) at different times could be calculated to maintain a stable liquid level above the producer, avoiding steam channeling accordingly. Besides, the model can also be used to predict optimal steam-injection rate under constant-pressure injection. Other SAGD dynamic performance predictions, such as SC expansion speed, could also be derived from this model. In addition, recommendations for liquid-level adjustment are offered on the basis of field conditions.

Reservoir Simulation of Hydrogen Sulfide Production During a Steam-Assisted-Gravity-Drainage Process by Use of a New Sulfur-Based Compositional Kinetic Model

SPE Journal ◽  
2016 ◽  
Vol 22 (01) ◽  
pp. 080-093 ◽  
Author(s):  
Simon V. Ayache ◽  
Violaine Lamoureux-Var ◽  
Pauline Michel ◽  
Christophe Preux
Keyword(s):  
Hydrogen Sulfide ◽  
Kinetic Model ◽  
Reservoir Simulation ◽  
Steam Injection ◽  
Laboratory Scale ◽  
Gravity Drainage ◽  
Production Data ◽  
Oil Sand ◽  
Oil Companies ◽  
Steam Assisted Gravity Drainage

Summary Steam injection is commonly used as a thermal enhanced-oil-recovery (EOR) method because of its efficiency for recovering hydrocarbons, especially from heavy-oil and bitumen reservoirs. Reservoir models simulating this process describe the thermal effect of the steam injection, but generally neglect the chemical reactions induced by the steam injection and occurring in the reservoir. In particular, these reactions can lead to the generation and production of the highly toxic and corrosive acid gas hydrogen sulfide (H2S). The overall objective of this paper is to quantitatively describe the chemical aquathermolysis reactions that occur in oil-sands reservoirs undergoing steam injections and to provide oil companies with a numerical model for reservoir simulators to forecast the H2S-production risks. For that purpose, a new sulfur-based compositional kinetic model has been developed to reproduce the aquathermolysis reactions in the context of reservoir modeling. It is derived from results gathered on an Athabasca oil sand from previous laboratory aquathermolysis experiments. In particular, the proposed reactions model accounts for the formation of H2S issued from sulfur-rich heavy oils or bitumen, and predicts the modification of the resulting oil saturate, aromatic, resin, and asphaltene (SARA) composition vs. time. One strength of this model is that it is easily calibrated against laboratory-scale experiments conducted on an oil-sand sample. Another strength is that its calibration is performed while respecting the constraints imposed by the experimental data and the theoretical principles. In addition, in this study no calibration was needed at reservoir scale against field-production data. In the paper, the model is first validated with laboratory-scale simulations. The thermokinetic modeling is then coupled with a 2D reservoir simulation of a generic steam-assisted gravity drainage (SAGD) process applied on a generic Athabasca oil-sand reservoir. This formulation allows investigating the H2S generation at reservoir scale and quantifying its production. The H2S- to bitumen-production ratio against time computed by the reservoir simulation is found to be consistent with production data from SAGD operations in Athabasca, endorsing the proposed methodology.

Optimisation of Steam Assisted Gravity Drainage [SAGD] for Improved Recovery from Unconsolidated Heavy Oil Reservoirs

2011 ◽  
Vol 367 ◽  
pp. 403-412 ◽  
Author(s):  
Babs Mufutau Oyeneyin ◽  
Amol Bali ◽  
Ebenezer Adom
Keyword(s):  
Oil Recovery ◽  
Heavy Oil ◽  
Oil Industry ◽  
Steam Injection ◽  
Thermal Capacity ◽  
Thermal Recovery ◽  
Viscosity Reduction ◽  
Gravity Drainage ◽  
Steam Assisted Gravity Drainage ◽  
The Impact

Most of the heavy oil resources in the world are in sandstone reservoir rocks, the majority of which are unconsolidated sands which presents unique challenges for effective sand management. Because they are viscous and have less mobility, then appropriate recovery mechanisms that lower the viscosity to the point where it can readily flow into the wellbore and to the surface are required. There are many cold and thermal recovery methods assisted by gravity drainage being employed by the oil industry. These are customised for specific reservoir characteristics with associated sand production and management problems. Steam Assisted Gravity Drainage (SAGD) based on horizontal wells and gravity drainage, is becoming very popular in the heavy oil industry as a thermal viscosity reduction technique. SAGD has the potential to generate a heavy oil recovery factor of up to 65% but there are challenges to ‘’realising the limit’’. The process requires elaborate planning and is influenced by a combination of factors. This paper presents unique models being developed to address the issue of multiphase steam-condensed water-heavy oil modelling. It addresses the effects of transient issues such as the changing pore size distribution due to compaction on the bulk and shear viscosities of the non-Newtonian heavy oil and the impact on the reservoir productivity, thermal capacity of the heavy oil, toe-to-heel steam injection rate and quality for horizontal well applications. Specific case studies are presented to illustrate how the models can be used for detailed risk assessment for SAGD design and real-time process optimisation necessary to maximise production at minimum drawdown. Nomenclature

Steam Injection Strategy and Energetics of Steam-Assisted Gravity Drainage

2005 ◽  
Author(s):  
Ian Donald Gates ◽  
Joseph Kenny ◽  
Ivan Lazaro Hernandez-Hdez ◽  
Gary L. Bunio
Keyword(s):  
Steam Injection ◽  
Gravity Drainage ◽  
Injection Strategy ◽  
Steam Assisted Gravity Drainage
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