Tailor-Made Workflow to Understand and Forecast H2S Production Risks in Thermal Projects

2021 ◽  
Author(s):  
Simon Victor Ayache ◽  
Julien Gasser-Dorado ◽  
Pauline Michel ◽  
Christophe Preux ◽  
Violaine Lamoureux-Var
Keyword(s):  
Steam Injection ◽  
Acid Gases ◽  
In Situ Extraction ◽  
Steam Chamber ◽  
Core Samples ◽  
Vertical Permeability ◽  
Numerical Predictions ◽  
Reservoir Simulator ◽  
High Level ◽  
H2s Production

Abstract In-situ extraction of heavy sulfured oil based on steam injection comes with a high level of risk in terms of H2S production, resulting from aquathermolysis reactions. This could lead to on-site living being casualties, environment damage, surface facilities and wells corrosion. Also, there is a strong need to understand aquathermolysis reactions and to forecast acid gases generation in such context. For that aim a tailor-made workflow was developed to estimate H2S concentration at the well-head. To meet these challenges, a 3-steps approach combining laboratory studies and numerical predictions has been developed. It firstly consists in a fast preliminary assessment of the highest H2S risk areas, based on the measurements of sulfur characteristics of reservoir core samples using our Rock-Eval Sulfur set-up. Then aquathermolysis experiments from the previously selected core samples are conducted in order to calibrate the compositional chemical model of the reservoir simulator. The latter is eventually used to carry out thermal compositional reactive simulations at field scale. The reservoir simulator allows simulations of SAGD processes and handles H2S distribution over oil/water/gas phases and its migration in these phases. Simulation results show that acid gases are generated within the steam chamber, before they accumulate at the chamber edges where they dissolve in the water and oil phases. This contributes to reduce viscosity, allowing the oil to flow along the steam chamber edges before it has reached the steam temperature. Therefore the H2S produced at surface is mainly carried towards the wells by water and to a lesser extent oil. This flowing oil has not reacted with the steam: its composition is close to the initial reservoir oil but enriched with dissolved gases. The steam chamber shape, the temperature distribution and the H2S produced at surface are strongly modified when heterogeneities are introduced in the reservoir model. Synthetic cases allow a deeper understanding of the effects of heterogeneities. Vertical permeability is thus found to be a key factor of H2S production variations. When steam reaches a lower permeability lithology, a delayed rise in H2S production at wellhead is observed as aquathermolysis reactions rates increase. Finally Foam Assisted-SAGD has been considered. While the foam improves the Steam-Oil ratio, no clear improvement was observed regarding the H2S production.

scholarly journals A Numerical Model for Investigating the Steam Conformance along the Dual-String Horizontal Wells in SAGD Operations

Energies ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3981
Author(s):  
Peng Li ◽  
Yanyu Zhang ◽  
Xiaofei Sun ◽  
Huijuan Chen ◽  
Yang Liu
Keyword(s):  
Pressure Drop ◽  
Horizontal Wells ◽  
Pressure Profile ◽  
Steam Injection ◽  
Steam Pressure ◽  
Optimization Method ◽  
Injection Time ◽  
Reservoir Model ◽  
Landing Position ◽  
Steam Chamber

Non-uniformity of the steam-assisted gravity drainage (SAGD) steam chamber significantly decreases the development of heavy oil reservoirs. In this study, to investigate the steam conformance in SAGD operations, a wellbore model is developed for fluid flow in dual-string horizontal wells. Then, a three-dimensional, three-phase reservoir model is presented. Next, the coupled wellbore and reservoir model is solved with a fully implicit finite difference method. Finally, the effects of the injector wellbore configuration, steam injection ratio and injection time on the steam conformance are investigated. The results indicate that under different injector wellbore configurations, the closer the differences between the pressure drop from the landing position of the short string to the heel of the wellbore and the pressure drop from the landing position of the short string to the toe of the wellbore, the better is the steam conformance. The smaller the difference in the steam injection rate between the long and short injection strings, the higher is the uniformity of the steam chamber. The injector annular pressure profile uniformity is consistent with the steam conformance. Creating a more uniform steam pressure in the annulus of the injector improves the uniformity of the steam chamber. The steam conformance decreases with increasing injection time, so the optimization method of steam chamber uniformity should be adjusted according to different injection times.

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.

Parametric Design of a Waterjet Pump by Means of Inverse Design, CFD Calculations and Experimental Analyses

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
Duccio Bonaiuti ◽  
Mehrdad Zangeneh ◽  
Reima Aartojarvi ◽  
Jonas Eriksson
Keyword(s):  
Flow Field ◽  
Parametric Study ◽  
Parametric Design ◽  
Inverse Design ◽  
Design Parameters ◽  
Pump Design ◽  
Hydrodynamic Efficiency ◽  
Numerical Predictions ◽  
High Level ◽  
Suction Performance

The present paper describes the parametric design of a mixed-flow water-jet pump. The pump impeller and diffuser geometries were parameterized by means of an inverse design method, while CFD analyses were performed to assess the hydrodynamic and suction performance of the different design configurations that were investigated. An initial pump design was first generated and used as baseline for the parametric study. The effect of several design parameters was then analyzed in order to determine their effect on the pump performance. The use of a blade parameterization, based on inverse design, led to a major advantage in this study, because the three-dimensional blade shape is described by means of hydrodynamic parameters, such as blade loading, which has a direct impact on the hydrodynamic flow field. On the basis of this study, an optimal configuration was designed with the aim of maximizing the pump suction performance, while at the same time, guaranteeing a high level of hydrodynamic efficiency, together with the required mechanical and vibrational constraints. The final design was experimentally tested, and the good agreement between numerical predictions and experimental results validated the design process. This paper highlights the contrasting requirements in the pump design in order to achieve high hydrodynamic efficiency or good cavitation performance. The parametric study allowed us to determine design guidelines in order to find the optimal compromise in the pump design, in cases where both a high level of efficiency and suction performance must simultaneously be achieved. The design know-how developed in this study is based on flow field analyses and on hydrodynamic design parameters. It has therefore a general validity and can be used for similar design applications.

Effect of Confinement and Well Interference on SAGD Performance: An Analytical Assessment

SPE Journal ◽  
2019 ◽  
Vol 24 (04) ◽  
pp. 1595-1612
Author(s):  
Zeinab Zargar ◽  
S. M. Farouq Ali
Keyword(s):  
Heat Loss ◽  
Moving Boundary ◽  
Steam Injection ◽  
Injection Rate ◽  
Unsteady Temperature ◽  
Steam Chamber ◽  
Heat Loss Rate ◽  
Well Spacing ◽  
Interface Length ◽  
First Time

Summary In this paper, we introduce, for the first time, an analytical approach for evaluating the effect of confinement and well interference on the SAGD process and achieving a better understanding of the situation. In the well-confinement stage of SAGD, there is adjacent-chamber interference, the effective head of drainage decreases, and the heat-loss rate decreases or, in a conservative design, remains constant. Our objectives were to predict the oil-production rate, steam-injection rate, thermal efficiency, steam-chamber velocity, unsteady temperature profile, heat distribution, and the cumulative steam/oil ratio (CSOR). In this approach, heat transfer was coupled with fluid flow. The governing equations were Darcy's law, volumetric balance, and heat conduction—constitutive equations indicating the temperature dependence of some physical properties. Our model was developed on the basis of a moving-boundary problem. The predicted oil rate remained constant during the sideways-expansion phase, while the steam-injection rate had to be constantly increased. After a determined confinement time, the oil rate started to decline with time because the decreasing steam-chamber interface length was offset by a decreasing head. The unsteady temperature profiles from the model showed that lower temperatures were predicted ahead of the interface owing to the confinement effect. Also, the model showed that, for a small lateral well spacing, confinement occurred earlier and heat loss started decreasing sooner, resulting in a lower CSOR than for a large spacing. It was shown that, even though the oil rate declined faster in a confined model rather than in an unconfined model, the reservoir depleted faster, just like the angle between the steam-chamber interface and the horizon. The results were validated using experimental data reported in the literature.

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.

Investigation of Blade and Disc Vibrations on the Upgraded Power Turbine for the THM 1304 Gas Turbine

2004 ◽  
Author(s):  
D. Frank ◽  
A. Kleinefeldt ◽  
U. Orth ◽  
W. Cline
Keyword(s):  
Gas Turbine ◽  
Power Output ◽  
Turbine Blades ◽  
Mode Shapes ◽  
Experimental Investigations ◽  
Numerical Predictions ◽  
Power Turbine ◽  
Temperature Capability ◽  
Blade System ◽  
High Level

As part of an ongoing uprating and upgrading program of the THM 1304 gas turbine directed towards increasing power output and efficiency as well as further improving the high level of availability, major design modifications were made on the power turbine (PT). New blades and vanes were designed for increased aerodynamic efficiency, improved high temperature capability, higher power output and higher nominal operating speed. This report presents the analytical and experimental investigations made on the vibration modes and frequencies of blades with pre-loaded interlocking tip shrouds. One focus is upon observed families of mode shapes at different nodal diameters. A comparison of finite-element results with test data shows how good predictions are in the case of coupled blade vibrations. The value of testing the vibration behavior of power turbine blades in the actual machine, over the complete speed range, becomes evident as an important addition to the numerical predictions and laboratory tests. Another focus is on the method of testing, including the telemetry system used and the problem of optimum placement of strain gages on the blades. The selected strain gage positions are crucial to the value and meaningfulness of the test results. The observed strain vibration amplitudes were compared with high-cycle-fatigue (HCF) data available for the blade material. It was shown that measured amplitudes were significantly below allowable levels over the complete range of operating power and speed. The analytical and experimental methods employed to determine blade mode shapes and frequencies for a blade system with pre-loaded tip shrouds are presented in detail.

scholarly journals Combination of Cyclic Steam Stimulation and Steam Flooding to Improve Oil Recovery in Unconsolidated Sand Heavy Oil Reservoir

2020 ◽  
Vol 9 (2) ◽  
pp. 80-87
Author(s):  
Ahmad Muraji Suranto ◽  
Boni Swadesi ◽  
Indah Widyaningsih ◽  
Ratna Widyaningsih ◽  
Sri Wahyu Murni ◽  
...  
Keyword(s):  
Oil Recovery ◽  
Reservoir Simulation ◽  
Heavy Oil ◽  
Steam Injection ◽  
Steam Chamber ◽  
Steam Flooding ◽  
Cyclic Steam Stimulation ◽  
Unconsolidated Sand ◽  
Reservoir Simulation Model ◽  
Steam Stimulation

Steam injection can be success in increasing oil recovery by determining the steam chamber growth. It will impact on the steam distribution and steam performance in covering hot areas in the reservoir.  An injection plan and a proper cyclic steam stimulation (CSS) schedule are critical in predicting how steam chamber can grow and cover the heat area. A reservoir simulation model will be used to understand how CSS really impact in steam chamber generation and affect the oil recovery. This paper generates numerous scenarios to see how steam working in heavy oil system particularly in unconsolidated sand reservoir. Combine the CSS method and steam injection continue investigate in this research. We will validate the scenarios based on the how fast steam chest can grow and get maximum oil recovery. Reservoir simulation resulted how steam chest behavior in unconsolidated sand to improve oil recovery; It concluded that by combining CSS and Steam Injection, we may get a faster steam chest growth and higher oil recovery by 61.5% of heavy oil system.

Effect of Flue Gas on Steam Chamber Expansion in Steamflooding

SPE Journal ◽  
2021 ◽  
pp. 1-11
Author(s):  
Teng Lu ◽  
Zhengxiao Xu ◽  
Xiaochun Ban ◽  
Dongliang Peng ◽  
Zhaomin Li
Keyword(s):  
Heat Exchange ◽  
Oil Recovery ◽  
Flue Gas ◽  
Gas Injection ◽  
Steam Injection ◽  
Injection Rate ◽  
Displacement Efficiency ◽  
Steam Condensation ◽  
Steam Chamber ◽  
Swept Volume

Summary The expansion of the steam chamber is very important for the recovery performance of steamflooding. In this paper, we discuss 1D and 2D sandpack experiments to performed analyze the effect of flue gas on steam chamber expansion and displacement efficiency in steamflooding. In addition, we examine the effect of flue gas acting on the steam condensation characteristics. The results show that within a certain range of injection rate, flue gas can significantly enlarge the swept volume and oil displacement efficiency of steam. However, when the flue gas injection rate is excessively high (the ratio of gas injection rate to steam injection rate exceeds 4), gas channels may form, resulting in a decline of oil recovery from steamflooding. The results of the 2D visualization experiments reveal that the swept volume of the steam chamber during steamflooding was small, and the remaining oil saturation in the reservoir was high, so the recovery was only 28%. The swept volume of the steam chamber for flue-gas-assisted steamflooding was obviously larger than that of steamflooding, and the recovery of flue-gas-assisted steamflooding in 2D experiments could reach 40.35%. The results of the steam condensation experiment indicate that flue gas could reduce the growth and coalescence rates of steam-condensed droplets on the cooling wall and increase the shedding period of the droplets. Macroscopically, flue gas could reduce the heat exchange rate between the steam and the reservoir and inhibit the rapid condensation and heat exchange of the steam near the injection well. As a result, flue gas could expand the steam chamber into the reservoir for heating and displacing oil.

Numerical and Experimental Investigation of a New Nonlinear Energy Sink for Passive Shock Mitigation

2012 ◽  
Author(s):  
Mohammad A. AL-Shudeifat ◽  
Nicholas Wierschem ◽  
Alexander F. Vakakis ◽  
Lawrence A. Bergman ◽  
Billie F. Spencer
Keyword(s):  
Linear Structure ◽  
Nonlinear Energy Sink ◽  
Initial Energy ◽  
Numerical Results ◽  
New Device ◽  
Numerical Predictions ◽  
Energy Sink ◽  
Experimental Findings ◽  
High Level ◽  
Nonlinear Energy

A new device functioning as an efficient nonlinear energy sink (NES) is explored here. The device consists of a mass coupled to a two-story linear test structure through a single-sided vibro-impact (VI) nonlinearity in one direction and a weak linear spring in both directions. This design is found to be more efficient for passive targeted energy transfer (TET) than existing NESs. It absorbs and rapidly dissipates a significant amount of the impulsive energy induced in the linear structure. In addition, some of this initial energy is pumped to higher modes of the structure and efficiently dissipated there. The numerical results have verified that the proposed single-sided VI NES maintains high level of performance over a broad range of high input energies. It performs near to its optimum even for severe induced shocks. Moreover, the numerical results have been experimentally verified; good agreement between numerical predictions and experimental findings was observed.

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