A Mathematical Model to Predict Solvent/Steam Flashing in Pure Solvent or Solvent/Steam Coinjection in Horizontal Producers

2021 ◽  
Author(s):  
Mazda Irani ◽  
Nasser Sabet ◽  
Farzad Bashtani ◽  
Kousha Gohari
Keyword(s):  
Flow Control ◽  
Latent Heat ◽  
Relative Permeability ◽  
Recovery Process ◽  
Liquid Pool ◽  
Solvent Injection ◽  
Recovery Processes ◽  
Flow Control Devices ◽  
Pure Solvent ◽  
Control Devices

Summary Although the steam assisted gravity drainage (SAGD) process is still the preferred thermal-recovery process method for Athabascan deposits in Alberta, Canada, the interest in solvent-based techniques is growing due to reduce greenhouse-gas (GHG) emissions and water treatment concerns. In SAGD process, the thermodynamic trapping or subcool trapping is quite efficient due to strongly dependency of bitumen viscosity to temperature. As Irani (2018) discussed subcool trapping for solvent applications such NsolvTM recovery process is inefficient due to week dependency of solvent viscosity to temperature. Other factor that effects the efficiency of the thermodynamic trapping is that the pure solvent injection recovery processes are operated at low pressure and it is not large temperature window for operators to apply large subcools. Such challenges make the pure solvent injection recovery processes a perfect case for deployment of Flow-Control-Devices (FCDs). FCDs have demonstrated significant potential for improving recovery in SAGD production wells. FCD experience in SAGD has been primarily positive and most producers performed better with FCDs. Application of FCDs are even more important in pure-solvent injection recovery processes due to large amount of solvent in the liquid pool and also low latent heat of solvent in comparison of water. With FCDs, the draw-down pressure is typically higher, resulting in flashing near the well bore, which is largely correlated to latent heat of the main fluid in the liquid pool. The flashing creates either steam or vapour breakthrough that causes the reduction in the relative permeability of the liquid phase. Such mobility reduction creates new equilibrium that stabilizes at lower rates. Such new equilibrium analysis is conducted by forcing a new temperature gradient to the model. Such condition creates an environment that leads into extensive solvent-breakthrough called solvent-coning in this study. The main output of such analysis is the produced solvent gas-fraction produced at the sand-face. The gas-fraction is an important input for the flow control devices (FCDs) especially at subcools close to the zero, as it controls its behavior. EoS model is also created and simplified to be possible to used in defining different equilibrium conditions. This type of analysis can help the operators evaluate the effectiveness of different type of FCDs, whether they are primarily momentum- or friction-style devices for application of the pure solvent injection recovery processes. This study is the first of its kind that couple the EoS and Darcy flow in the liquid pool. The model includes all the factors into a liquid-relative-permeability, and limitation of the liquid flow into producer is modeled by Darcy flow and reduction of such relative-permeability.

Modeling the Conformance Improvement Using Flow Control Devices in Infill Wells Adjacent to SAGD Well Pairs: No Flashing

SPE Journal ◽  
2020 ◽  
Vol 25 (02) ◽  
pp. 800-819
Author(s):  
Mazda Irani ◽  
Sahar Ghannadi
Keyword(s):  
Flow Control ◽  
Production Rate ◽  
Hot Spots ◽  
Interface Velocity ◽  
Liquid Pool ◽  
Productivity Index ◽  
Flow Control Devices ◽  
Novel Approach ◽  
Control Devices ◽  
Pressure Driven

Summary Late in the life of the steam-assisted gravity drainage (SAGD) process, drilling a single, horizontal infill well (called a wedge well by some) has become a common practice in the oil bank located between two mature SAGD well pairs to produce bitumen that has been heated and mobilized but could not be effectively drained by gravity because of the large lateral location relative to that of the SAGD producers. Because this oil bank is surrounded by a large, depleted steam chamber created by the existing well pairs, little heat is required to mobilize bitumen. Consequently, the incremental steam/oil ratio (SOR) to produce this bitumen can be reduced using these infill wells. One of the challenges, however, in producing such wells is that nonuniform drainage and local hot spots can be readily created in the first year of their operation that in many cases require steam stimulations and completion retrofits, such as with flow control devices (FCDs), to improve the drainage profile. This work is a continuation of three previous parts (presented in Irani 2018, 2019, and Irani and Gates 2018) on SAGD near-wellbore drainage behavior, control, and some of the modeling challenges. In previous parts, productivity index (PI) models were formulated specifically for an SAGD well producing emulsion from the liquid pool under changing operational subcool conditions. Given the conformance challenges, many infill wells have greater risk of developing hot spots than SAGD producers, suggesting that the wellbore modeling, which includes the response of the FCDs, should be coupled with a PI model appropriately for such wells. Currently, there is no suitable PI model to predict drainage rates in these SAGD infill wells. The production rate in these wells is highly pressure driven in contrast to the SAGD reservoir drainage process that is dominantly gravity driven. In this study, a time variable PI model is analytically developed for infill wells considering a developed pressure-driven formulation. The model accurately shows fluctuations in the production rate because of flowing bottomhole pressure (FBHP) variations and can be used for both oil rate prediction and forecasting and wellbore hydraulic design for infill wells. This novel approach is the first of its kind to incorporate temperature variation, pressure dependency, and steam interface velocity within a PI model for infill wells. To achieve higher efficiencies, the location and characteristics of the FCDs along the infill wells should be optimized. In this study, the mathematical PI model of infill wells is coupled with an FCD model, and the analysis of different configurations of FCDs is evaluated. The results of this work show an uplift in a well completed with liner-deployed FCDs, but because flashing is not incorporated in the PI model, the pressure drop predicted within these FCDs for produced fluids with free steam vapor is found to be less than reality. Ignoring flashing through the FCD provides higher density of the fluid passing through the venturi. Therefore, the FCD creates less choking with reduced conformance control than would be expected if flashing was considered.

On Subcool Control in SAGD Producers—Part II: Localized-Hot-Spots Effects and Optimization of Flow-Control Devices

SPE Journal ◽  
2019 ◽  
Vol 24 (04) ◽  
pp. 1613-1629 ◽  
Author(s):  
Mazda Irani
Keyword(s):  
Flow Control ◽  
Hot Spots ◽  
Hot Spot ◽  
Large Fraction ◽  
Liquid Pool ◽  
Gas Production ◽  
Differential Pressure ◽  
Steam Chamber ◽  
Flow Control Devices ◽  
Control Devices

Summary At the base of a steam-assisted-gravity-drainage (SAGD) steam chamber, a liquid pool is developed, which is a key component for bitumen production. A producer is placed in the liquid pool, and its production is mainly controlled by its liquid level and the temperature gradient across its depth. A “subcool control” or “thermodynamic steam-trap control” is a typical operating strategy to control steam coning to the producer. Part I of this study (Irani 2018) presented a methodology to evaluate the production rate for a given pressure drawdown and subcool in a SAGD liquid pool; and Part III (Irani and Gates 2018) modified such a formulation for a stability analysis of the Nsolv™ (Nenniger and Nenniger 2000, 2001) process that contained a large fraction of liquid butane. In this study, first, the effect of localized hot spots on well control is formulated as a virtual skin factor in the liquid-pool deliverability equation. The results of this work suggest that a longer hot spot will yield to lower differential pressure and make it more challenging to control the steam breakthrough by choking the well at a given rate. Another key finding is that the steam coning becomes less controllable for higher-permeability reservoirs. Flow-control devices (FCDs) have been used extensively in horizontal wells for conventional oil and gas production to prevent early water breakthrough or gas coning. Although FCDs are commonly installed to prevent steam coning after steam breakthrough and to manage hot spots as retrofit completions by SAGD operators, in recent years, FCDs have been often installed to improve SAGD well-pair performance as part of the initial completion. The benefits associated with this technology in the SAGD industry have been studied with reservoir simulations and validated with field experience, but a theoretical study that discusses the main factors for a correct FCD selection on the basis of operational conditions and reservoir heterogeneity is required. In this study, the liner-deployed FCD and liquid-pool systems are coupled, and two criteria are suggested for a design of liner-deployed FCDs on the basis of the pressure-drop ratio of the FCD relative to the liquid pool (ΔPFCD/ΔPpool) and the coefficient of variation (CoV) of inflow for the liner-deployed-FCD wellbore (CoVFCD). The results of this study show that in higher-permeability reservoirs, the ideal FCD design should have more ports to reduce the differential pressure to flow response. While FCDs will improve inflow conformance relative to completions without FCDs, the effect of permeability in this improvement is minimal. This improvement is larger in applications operating at lower target subcool values. Reducing the target-wellbore subcool value can improve well deliverability twofold: First, FCD-completed wells produce more at lower subcools and, second, reducing the subcool value helps to improve inflow uniformity along the length of the lateral. By effectively removing the fluids available to the producer, the growth of the steam chamber can be maximized through accelerated injection rates.

scholarly journals Prediction of flow-control devices' noise with modified acoustic perturbation equations

2020 ◽  
Vol 22 (3) ◽  
pp. 619-627
Author(s):  
Luca Fenini ◽  
Stefano Malavasi
Keyword(s):  
Flow Control ◽  
Fluid Dynamic ◽  
International Standards ◽  
The Other ◽  
Computational Time ◽  
Noise Prediction ◽  
Acoustic Perturbation ◽  
Flow Control Devices ◽  
Control Devices ◽  
Perturbation Equations

Abstract Fluid-dynamic noise emissions produced by flow-control devices inside ducts are a concerning issue for valve manufacturers and pipeline management. This work proposes a modified formulation of Acoustic Perturbation Equations (APE) that is applicable to industrial frameworks where the interest is addressed to noise prediction according to international standards. This formulation is derived from a literature APE system removing two terms allowing for a computational time reduction of about 20%. The physical contribution of the removed terms is discussed according to the literature. The modified APE are applied to the prediction of the noise emitted by an orifice. The reliability of the new APE system is evaluated by comparing the Sound Pressure Level (SPL) and the acoustic pressure with the ones returned by LES and literature APE. The new formulation agrees with the other methods far from the orifice: moving over nine diameters downstream of the trailing edge, the SPL is in accordance with the other models. Since international standards characterize control devices with the noise measured 1 m downstream of them, the modified APE formulation provides reliable and faster noise prediction for those devices with outlet diameter, d, such that 9d < 1 m.

The Application of Shape Memory Alloy as Vortex Generators and Flow Control Devices for Enhanced Convective Heat Transfer

2007 ◽  
Author(s):  
Mohd. S. Aris ◽  
Ieuan Owen ◽  
Chris. J. Sutcliffe
Keyword(s):  
Heat Transfer ◽  
Flow Control ◽  
Shape Memory ◽  
Convective Heat Transfer ◽  
Heat Transfer Enhancement ◽  
Convective Heat ◽  
Vortex Generators ◽  
Transfer Enhancement ◽  
Flow Control Devices ◽  
Control Devices

This paper is concerned with convective heat transfer enhancement of heated surfaces through the use of vortex generators and flow control devices. A preliminary proof-of-concept investigation has been carried out into the use of active vortex generators and flow control elements, both manufactured from Shape Memory Alloys (SMAs) which are activated at set temperatures. The vortex generators change their shape to intrude further into the flow at high temperature to enhance heat transfer, while they maintain a low profile at low temperatures to minimise flow pressure losses. One set of vortex generators was made from pre-alloyed powders of SMA material in an advanced rapid prototyping process known as Selective Laser Melting (SLM). Another set of devices was also made from commercially available flat annealed thin SMA sheets for comparison purposes. The flow control elements are devices that preferentially guide the flow to heated parts of a surface, again using temperature-activated SMAs. Promising results were obtained for both the vortex generator and flow control device when their temperatures were varied from 20° to 85°C. The vortex generators responded by increasing their angle of attack from 20° to 35° while the wavy flow control elements straightened out at higher temperatures. As the designs were two-way trained, they regain their initial position and shape at a lower temperature. The surface temperature of the heated plate on which the active devices were positioned reduced between 8 to 51%, indicating heat transfer enhancement due to the generated vortices and changes in air flow rates.

Experimental Analysis on a Model of a Small Ducted Wind Turbine Equipped with Passive Flow Control Devices

2021 ◽  
Author(s):  
Elena-Alexandra Chiulan ◽  
Costin Ioan Cosoiu ◽  
Andrei-Mugur Georgescu ◽  
Anton Anton ◽  
Mircea Degeratu
Keyword(s):  
Flow Control ◽  
Wind Turbine ◽  
Experimental Analysis ◽  
Passive Flow Control ◽  
Passive Flow ◽  
Flow Control Devices ◽  
Control Devices

Liner Deployed Flow Control Devices in SAGD Infill Producers

2021 ◽  
Author(s):  
Michael Hardcastle ◽  
Ryan Holmes ◽  
Frank Abbott ◽  
Jesse Stevenson ◽  
Aubrey Tuttle
Keyword(s):  
Flow Control ◽  
Oil And Gas ◽  
Distributed Temperature Sensing ◽  
Steam Assisted Gravity Drainage ◽  
Well Production ◽  
Flow Control Devices ◽  
Control Devices ◽  
The Impact ◽  
Mobility Variable

Abstract Connacher Oil and Gas has deployed Flow Control Devices (FCDs)on an infill well liner as part of a Steam Assisted Gravity Drainage (SAGD) exploitation strategy. Infill wells are horizontal wells drilled in between offsetting SAGD well pairs in order to access bypassed pay and accelerate recovery. These wells can have huge variability in productivity, based on several factors: variable initial temperature due to variable steam chamber development and initial mobility variable injectivity from day one limiting steam circulation and stimulation significant hot spots during production that limit drawdown of the well and oil productivity FCDs have shown great value in several SAGD schemes and are becoming common throughout SAGD applications to manage similar challenges in SAGD pairs, but their application in infill wells is less prevalent and presents a novel challenge to design and evaluate performance. This case study will examine the theory, operation, and early field results of this field trial. Density-based FCDs designed for thermal operations were selected to minimize the impact of viscous fluids commonly encountered early in cold infill well production. The design also limited steam outflow during the stimulation phase, where steam is injected in order to initiate production of the well. Distributed Temperature Sensing (DTS) data, pressures and rates are utilized to analyze the impact of the FCDs towards conformance of the well in the early life. The value of FCDs has led to further piloting of this technology in a second group of nine infill wells, where further value is to be extracted using slimmer wellbores.

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