Understanding the Steam-Hammer Mechanism in Steam-Assisted-Gravity-Drainage Wells

SPE Journal ◽  
2013 ◽  
Vol 18 (06) ◽  
pp. 1181-1201 ◽  
Author(s):  
Mazda Irani
Keyword(s):  
Water Hammer ◽  
Thermal Recovery ◽  
Viscosity Reduction ◽  
Gravity Drainage ◽  
Water Drainage ◽  
Steam Quality ◽  
Recovery Method ◽  
Steam Assisted Gravity Drainage ◽  
Production Tubing ◽  
Injection Phase

Summary Steam-assisted gravity drainage (SAGD) is one of the successful thermal-recovery techniques applied in Alberta oil-sands reservoirs. When considering in-situ production from bitumen reservoirs, viscosity reduction is necessary to mobilize bitumen, thereby flowing toward the production well. Steam injection is currently the most effective thermal-recovery method. Although steamflooding is commercially viable, condensation-induced water hammer (CIWH) resulting from rapid steam-pocket condensation can be a challenging operational problem. In steamflooding, steam is injected through a well down to the reservoir, warming it to temperatures of 150 to 270°C (302 to 518°F) to liquefy the bitumen inside the reservoir (Garnier et al. 2008; Xie and Zahacy 2011). The liquefied bitumen then drains to a lower well through which it is produced to the surface. In this process, steam pockets can become entrapped in subcooled condensate inside either the injection or the production tubing, causing a rapid collapse of the steam pocket. This type of rapid condensation is commonly referred to as "steam hammer." In this study, three different scenarios are explored to better understand steam-hammer situations in SAGD wells. These scenarios are at injectors or producers during the startup phase (or circulation phase), in the injection tubing during the injection phase, and in the production tubing during the injection phase. Modeling each of these scenarios indicates that a steam-hammer occurrence is likely in two of the three scenarios, but that its incidence can be mitigated. The likely scenarios for a steam-hammer occurrence are in either the injection or the production tubing during the startup phase, and in the injection tubing during the injection phase. Steam-hammer occurrences during the circulation period can be controlled by lowering the injection pressure and controlling water drainage into the reservoir. Flow shocks that occur as a result of countercurrent flow limiting (CCFL) are very likely to take place in the injection tubing during the injection phase but can be controlled by injecting at a higher steam quality. The least likely scenario for a steam-hammer occurrence is in the production tubing during the injection phase. This is because the produced (or breakthrough) steam temperature would need to be more than 20°C higher than the produced-liquid temperature to start a water-hammer condition.

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

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.

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.

scholarly journals Introduction and investigation of magnetic location system for steam-assisted gravity drainage dual-horizontal heavy oil wells

2018 ◽  
Vol 10 (9) ◽  
pp. 168781401879897 ◽  
Author(s):  
Yong Chen ◽  
Hao Yi ◽  
Chuan He
Keyword(s):  
Measurement Error ◽  
Oil Recovery ◽  
Detection System ◽  
Rapid Development ◽  
Gravity Drainage ◽  
Horizontal Projection ◽  
Recovery Method ◽  
Location System ◽  
Steam Assisted Gravity Drainage ◽  
Magnetic Source

Steam-assisted gravity drainage has been proven to be an effective oil recovery method, and the technology of magnetic location is the key to steam-assisted gravity drainage. In view of the rapid development of this technology in China, a new magnetic location system with intellectual property rights was developed in this article, including mechanical parts and circuit section of detection system. Specific structure, operating principle, and technical parameters of magnetic source generator and detection system were designed and analyzed. The ground test results show that the source generator is powered by an alternating current of 4–7 A, the detection system can probe the magnetic field signal 25 m away from the magnetic source generator, and the measurement error is less than 3% by comparison of measured with actual spacing distance. The steam-assisted gravity drainage dual-horizontal well group in Zhong 37 Well block in Fengcheng Oilfield is chosen for further experiment with the developed magnetic location technology. The results of field experiment show the trajectories of Wells I (injection well) and P (production well) are basically matched in the horizontal projection, and the measurement error is within the allowable range. The magnetic location system developed in this article can meet the operational requirement in steam-assisted gravity drainage dual-horizontal wells.

Understanding the Thermo-Hydromechanical Pressurization in Two-Phase (Steam/Water) Flow and Its Application in Low-Permeability Caprock Formations in Steam-Assisted-Gravity-Drainage Projects

SPE Journal ◽  
2014 ◽  
Vol 19 (06) ◽  
pp. 1126-1150 ◽  
Author(s):  
Sahar Ghannadi ◽  
Mazda Irani ◽  
Rick Chalaturnyk
Keyword(s):  
Pore Pressure ◽  
Shear Failure ◽  
Thermal Recovery ◽  
Subcritical State ◽  
Gravity Drainage ◽  
Low Permeability ◽  
Steam Chamber ◽  
Steam Assisted Gravity Drainage ◽  
Caprock Integrity ◽  
Casing Failure

Summary Steam-assisted gravity drainage (SAGD) is one successful thermal-recovery technique applied in Alberta oil-sand reservoirs. When considering in-situ production from bitumen reservoirs, one must reduce viscosity for the bitumen to flow toward the production well. Steam injection is currently the most promising thermal-recovery method. Although steamflooding has proved to be a commercially viable way to extract bitumen from bitumen reservoirs, caprock integrity and the risk of losing steam containment can be challenging operational problems. Because permeability is low in Albertan thermal-project caprock formations, heating greatly increases the pressure on any water trapped in pores as a result of water thermal expansion. This water also sees a great increase in volume as it flashes to steam, causing a large effective-stress reduction. After this condition is established, pore-pressure increases can lead to caprock shear failure or tensile fracturing, and to subsequent caprock-integrity failure or potential casing failure. It is typically believed that low-permeability caprocks impede the transmission of pore pressure from reservoirs, making them more resistant to shear failure (Collins 2005, 2007). In considering the “thermo-hydromechanical pressurization” physics, low-permeability caprocks are not always more resistant. As the steam chamber rises into the caprock, the heated pore fluids may flash to steam. Consequently, there is a vapor region between the steam-chamber interface penetrated into the caprock and the water region within the caprock which is still at a subcritical state. This study develops equations for fluid-mass and thermal-energy conservation, evaluating the thermo-hydromechanical pressurization in low-permeability caprocks and the flow of steam and water after steam starts to be injected as part of the SAGD process. Calculations are made for both short-term and long-term responses, and evaluated thermal pressurization is compared for caprocks with different stiffness states and with different permeabilities. One can conclude that the stiffer and less permeable the caprock, the greater the thermo-hydromechanical pressurization; and that the application of SAGD can lead to high pore pressure and potentially to caprock shear, and to subsequent steam release to the surface or potential casing failure.

Exploration Method for Extra Heavy Oil Reservoir with Top Water

2011 ◽  
Vol 243-249 ◽  
pp. 6237-6240
Author(s):  
You Jun Ji ◽  
Jian Jun Liu ◽  
Nelly Zhang
Keyword(s):  
Heavy Oil ◽  
Volume Fraction ◽  
Thermal Recovery ◽  
Gravity Drainage ◽  
Oil Reservoir ◽  
Steam Assisted Gravity Drainage ◽  
Production Parameters ◽  
Liaohe Oilfield ◽  
Modeling Software ◽  
Heavy Oil Reservoir

For an extra heavy oil reservoir with top water in Liaohe Oilfield, it is inefficiently and hard to produce by conventional thermal recovery. In this regard, the numerical modeling software – CMG is used to analyze the recovery of this reservoir by Steam-Assisted Gravity Drainage (SAGD) and Steam and incondensable gas-assisted gravity push (SAGP). The production indicators, development effects and distribution of field parameters of these two techniques are contrasted and analyzed, and the injection and production parameters for application of SAGP in wells are optimized. The study shows that, for this extra heavy oil reservoir with top water, SAGP is more effective than SAGD, and the former can reduce the steam demand, improve the oil/steam ratio (OSR), prolong the development and enhance the recovery. It is recommended, during application of SAGP on site, to inject nitrogen at volume fraction of 30-40% and when the steam chamber expands to a section with 1/3 net pay thickness away to the top water.

A Dual-Directional Flow Control Device for Cyclic Steam Stimulation Applications

2021 ◽  
pp. 1-8
Author(s):  
Da Zhu
Keyword(s):  
Flow Control ◽  
Control Device ◽  
Thermal Recovery ◽  
Asia Pacific ◽  
Steam Quality ◽  
Recovery Method ◽  
Directional Flow ◽  
Cyclic Steam Stimulation ◽  
Flow Control Device ◽  
Steam Stimulation

Summary Cyclic steam stimulation (CSS) is one the most effective thermal recovery methods. It is widely used as the primary thermal recovery method to recover heavy oil fields in the Middle East, the Asia-Pacific region, and North and South America. In this paper, a novel dual-directional flow control device (FCD) will be introduced. This FCD technology can allocate accurate steam outflow into the reservoir formation and improve steam quality during the steam injection period and can mitigate steam breakthrough from the neighboring wells during the production period. In the first section, we give a brief introduction on CSS and the main issues encountered in the field operation. A multidirectional flow control nozzle specifically designed for CSS application will be presented. Design philosophy in thermodynamics and hydrodynamics of the nozzle will be discussed in detail. Field performance results, computational fluid dynamics (CFD), and flow loop testing data will be shown to evaluate the performance of the technology. The application of the technology in steam-assisted thermal applications will be introduced. Well-known issues such as erosion and scaling on the FCD tools will be studied in the end.

Sign in / Sign up

Export Citation Format

Share Document