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.

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

scholarly journals 3D experimental investigation on enhanced oil recovery by flue gas assisted steam assisted gravity drainage

2021 ◽  
pp. 014459872110065
Author(s):  
Lei Tao ◽  
Xiao Yuan ◽  
Sen Huang ◽  
Nannan Liu ◽  
Na Zhang ◽  
...  
Keyword(s):  
Enhanced Oil Recovery ◽  
Oil Recovery ◽  
Heavy Oil ◽  
Flue Gas ◽  
Physical Simulation ◽  
Thermal Recovery ◽  
Production Performance ◽  
Experimental Result ◽  
Gravity Drainage ◽  
Steam Assisted Gravity Drainage

Flue gas assisted steam assisted gravity drainage (SAGD) is a frontier technology to enhance oil recovery for heavy oil reservoirs. The carbon dioxide generated from the thermal recovery of heavy oil can be utilized and consumed to mitigate climate warming for the world. However, most studies are limited to merely use numerical simulation or small physical simulation device and hardly focus on large scale three-dimensions experiment, which cannot fully investigate the enhanced oil recovery (EOR) mechanism of flue gas assisted SAGD, thus the effect of flue gas on SAGD production performance is still not very clear. In this paper, large-scaled and high temperature and pressure resistant 3D physical simulation experiment was conducted, where simulated the real reservoir to a maximum extent, and systematically explored the EOR mechanisms of the flue gas assisted SAGD. Furthermore, the differences between the steam huff and puff, SAGD and flue gas assisted SAGD are discussed. The experimental result showed that the production effect of SAGD was improved by injecting flue gas, with the oil recovery was increased by 5.7%. With the help of thermocouple temperature measuring sensors, changes of temperature field display that flue gas can promote lateral re-development of the steam chamber, and the degree of reservoir exploitation around the horizontal wells has been increased particularly. What’s more, the addition of flue gas further increased the content of light components and decreased the content of heavy by comparing the content of heavy oil components produced in different production times.

Approximate Physics-Discrete Simulation of the Steam-Chamber Evolution in Steam-Assisted Gravity Drainage

SPE Journal ◽  
2018 ◽  
Vol 24 (02) ◽  
pp. 477-491 ◽  
Author(s):  
Enrique Gallardo ◽  
Clayton V. Deutsch
Keyword(s):  
Oil Sands ◽  
Recovery Process ◽  
Thermal Recovery ◽  
Porous Media Flow ◽  
Gravity Drainage ◽  
Discrete Simulation ◽  
Flow Equations ◽  
Integrity Assessment ◽  
Steam Chamber ◽  
Steam Assisted Gravity Drainage

Summary Steam-assisted gravity drainage (SAGD) is a thermal-recovery process to produce bitumen from oil sands. In this technology, steam injected in the reservoir creates a constantly evolving steam chamber while heated bitumen drains to a production well. Understanding the geometry and the rate of growth of the steam chamber is necessary to manage an economically successful SAGD project. This work introduces an approximate physics-discrete simulator (APDS) to model the steam-chamber evolution. The algorithm is formulated and implemented using graph theory, simplified porous-media flow equations, heat-transfer concepts, and ideas from discrete simulation. The APDS predicts the steam-chamber evolution in heterogeneous reservoirs and is computationally efficient enough to be applied over multiple geostatistical realizations to support decisions in the presence of geological uncertainty. The APDS is expected to be useful for selecting well-pair locations and operational strategies, 4D-seismic integration in SAGD-reservoir characterization, and caprock-integrity assessment.

Feasibility of electromagnetic methods to detect and image steam-assisted gravity drainage steam chambers

Geophysics ◽  
2016 ◽  
Vol 81 (4) ◽  
pp. E227-E241 ◽  
Author(s):  
Sarah G. R. Devriese ◽  
Douglas W. Oldenburg
Keyword(s):  
Oil Recovery ◽  
Oil Sands ◽  
Vertical Component ◽  
Design Procedure ◽  
Production Costs ◽  
Three Dimensions ◽  
Gravity Drainage ◽  
Steam Chamber ◽  
Steam Assisted Gravity Drainage ◽  
Mcmurray Formation

We have investigated the use of electric and electromagnetic (EM) methods to monitor the growth of steam-assisted gravity drainage (SAGD) steam chambers. SAGD has proven to be a successful method for extracting bitumen from the Athabasca oil sands in Alberta, Canada. However, complexity and heterogeneity within the reservoir could impede steam chamber growth, thereby limiting oil recovery and increase production costs. Using seismic data collected over an existing SAGD project, we have generated a synthetic steam chamber and modeled it as a conductive body within the bitumen-rich McMurray Formation. Simulated data from standard crosswell electrical surveys, when inverted in three dimensions, show existence of the chamber but lack the resolution necessary to determine the shape and size. By expanding to EM surveys, our ability to recover and resolve the steam chamber is significantly enhanced. We use a simplified survey design procedure to design a variety of field surveys that include surface and borehole transmitters operating in the frequency or time domain. Each survey is inverted in three dimensions, and the results are compared. Importantly, despite the shielding effects of the highly conductive cap rock over the McMurray Formation, we have determined that it is possible to electromagnetically excite the steam chamber using a large-loop surface transmitter. This motivates a synthetic example, constructed using the geology and resistivity logging data of a future SAGD site, where we simulate data from single and multiple surface loop transmitters. We have found that even when measurements are restricted to the vertical component of the electric field in standard observation wells, if multiple transmitters are used, the inversion recovers three steam chambers and discerns an area of limited steam growth that results from a blockage in the reservoir. The effectiveness of the survey shows that this EM methodology is worthy of future investigation and field deployment.

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.

scholarly journals A Workflow for Optimization of Flow Control Devices in SAGD

Energies ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 3237
Author(s):  
Anas Sidahmed ◽  
Siavash Nejadi ◽  
Alireza Nouri
Keyword(s):  
Flow Control ◽  
Oil Sands ◽  
Net Present Value ◽  
Gravity Drainage ◽  
Operation Performance ◽  
Steam Assisted Gravity Drainage ◽  
Mcmurray Formation ◽  
Flow Control Devices ◽  
Recovery Technique ◽  
Control Devices

In McMurray Formation, steam assisted gravity drainage is used as the primary in-situ recovery technique to recover oil sands. Different geological reservoir settings and long horizontal wells impose limitations and operational challenges on the implementation of steam-assisted gravity drainage (SAGD). The dual-string tubing system is the conventional completion scheme in SAGD. In complex reservoirs where dual-string completion cannot improve the operation performance, operators have adopted flow control devices (FCDs) to improve project economics. FCDs secure more injection/production points along the horizontal sections of the SAGD well pairs, hence, they maximize ultimate bitumen recovery and minimize cumulative steam-oil ratio (cSOR). This paper will focus on the optimization of outflow control devices (OCDs) in SAGD reservoirs with horizontal wellbore undulations. We present the detailed optimization workflow and show the optimization results for various scenarios with well pair trajectory undulation. Comparing the results of the optimized OCDs case with a dual-string case of the same SAGD model shows improvements in steam distribution, steam chamber growth, bitumen production, and net present value (NPV).

Steam-Assisted Gravity-Drainage Performance With Temperature-Dependent Properties—A Semianalytical Approach

SPE Journal ◽  
2016 ◽  
Vol 22 (03) ◽  
pp. 902-911 ◽  
Author(s):  
M.. Heidari ◽  
S. H. Hejazi ◽  
S. M. Farouq Ali
Keyword(s):  
Oil Sands ◽  
Oil Production ◽  
Thermal Recovery ◽  
Effect Of Temperature ◽  
Gravity Drainage ◽  
Temperature Dependent ◽  
Rock Density ◽  
Steam Chamber ◽  
Steam Assisted Gravity Drainage ◽  
Temperature Dependent Properties

Summary Steam-assisted gravity drainage (SAGD) is one of the successful in-situ thermal-recovery methods for oil-sands production. In this paper, we provide a simple semianalytical model that can accurately analyze an SAGD project with variable properties. In particular, we investigate the effect of temperature-dependent properties such as thermal conductivity, heat capacity, and rock density on SAGD performance. The proposed model sequentially solves the transient nonlinear heat-transfer equation coupled with the continuity equation with Kirchhoff's transformation and the heat integral method (HIM). A criterion for timestep selection is defined on the basis of the Courant and Péclet numbers to guarantee the stability of the sequential technique. The results illustrate that the temperature-dependent physical properties affect temperature distributions ahead of steam chamber which consequently have a significant impact on the cumulative oil production and oil-production rate. Moreover, the results show that the temperature profile ahead of the steam chamber changes with time and space, and a 2D transient assumption for SAGD modeling is necessary. The semianalytical model runs in a small fraction of numerical-simulator runtime, yet it provides reasonable results. Thus, it has the potential to be used as a tool for quick SAGD evaluations.

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