A Case History for an Integrated Asset Model with Fluid Delumping for a Complex Gas Condensate Field

2021 ◽  
Author(s):  
Mohamed Ibrahim Mohamed ◽  
Ahmed Mahmoud El-Menoufi ◽  
Eman Abed Ezz El-Regal ◽  
Ahmed Mohamed Ali ◽  
Khaled Mohamed Mansour ◽  
...  
Keyword(s):  
Development Planning ◽  
Production Optimization ◽  
Operating Conditions ◽  
Gas Condensate ◽  
Western Desert ◽  
Design Parameters ◽  
Compositional Model ◽  
Compositional Approach ◽  
Process Plant ◽  
Black Oil

Abstract Field development planning of gas condensate fields using numerical simulation has many aspects to consider that may lead to a significant impact on production optimization. An important aspect is to account for the effects of network constraints and process plant operating conditions through an integrated asset model. This model should honor proper representation of the fluid within the reservoir, through the wells and up to the network and facility. Obaiyed is one of the biggest onshore gas field in Egypt, it is a highly heterogeneous gas condensate field located in the western desert of Egypt with more than 100 wells. Three initial condensate gas ratios are existing based on early PVT samples and production testing. The initial CGR values are as following;160, 115 and 42 STB/MMSCF. With continuous pressure depletion, the produced hydrocarbon composition stream changes, causing a deviation between the design parameters and the operating parameters of the equipment within the process plant, resulting in a decrease in the recovery of liquid condensate. Therefore, the facility engineers demand a dynamic update of a detailed composition stream to optimize the system and achieve greater economic value. The best way to obtain this compositional stream is by using a fully compositional integrated asset model. Utilizing a fully compositional model in Obaiyed is challenging, computationally expensive, and impractical, especially during the history match of the reservoir numerical model. In this paper, a case study for Obaiyed field is presented in which we used an alternative integrated asset modeling approach comprising a modified black-oil (MBO) that results in significant timesaving in the full-field reservoir simulation model. We then used a proper de-lumping scheme to convert the modified black oil tables into as many components as required by the surface network and process plant facility. The results of proposed approach are compared with a fully compositional approach for validity check. The results clearly identified the system bottlenecks. The model enables the facility engineers to keep the conditions of the surface facility within the optimized operating envelope throughout the field's lifetime and will be used to propose new locations and optimize the tie-in location of future wells in addition to providing flow assurance indications throughout the field's life and under different network configurations.

A Practical Approach to Expedite a Pore to Process Simulation Model for a Rich Gas Condensate Reservoir – Case Study

2021 ◽  
Author(s):  
Mohamed Ibrahim Mohamed ◽  
Ahmed Mahmoud El-Menoufi ◽  
Eman Abed Ezz El-Regal ◽  
Ahmed Mohamed Ali ◽  
Khaled Mohamed Mansour ◽  
...  
Keyword(s):  
Simulation Model ◽  
Production Optimization ◽  
Operating Conditions ◽  
Gas Condensate ◽  
Western Desert ◽  
Design Parameters ◽  
Compositional Approach ◽  
Process Plant ◽  
Black Oil

Abstract Field development planning of gas condensate fields using numerical simulation has many aspects to consider that may lead to a significant impact on production optimization. An important aspect is to account for the effects of network constraints and process plant operating conditions through an integrated asset model. This model should honor proper representation of the fluid within the reservoir, through the wells and up to the network and facility. Obaiyed is one of the biggest onshore gas field in Egypt, it is a highly heterogeneous gas condensate field located in the western desert of Egypt with more than 100 wells. Three initial condensate gas ratios are existing based on early PVT samples and production testing. The initial CGRs as follows;160, 115 and 42 STB/MMSCF. With continuous pressure depletion, the produced hydrocarbon composition stream changes, causing a deviation between the design parameters and the operating parameters of the equipment within the process plant, resulting in a decrease in the recovery of liquid condensate. Therefore, the facility engineers demand a dynamic update of a detailed composition stream to optimize the system and achieve greater economic value. The best way to obtain this compositional stream is by using a fully compositional integrated asset model. Utilizing a fully compositional model in Obaiyed is challenging, computationally expensive, and impractical, especially during the history match of the reservoir numerical model. In this paper, a case study for Obaiyed field is presented in which we used an alternative integrated asset modeling approach comprising a modified black-oil (MBO) that results in significant timesaving in the full-field reservoir simulation model. We then used a proper de-lumping scheme to convert the modified black oil tables into as many components as required by the surface network and process plant facility. The results of proposed approach are compared with a fully compositional approach for validity check. The results clearly identified the system bottlenecks. The model can be used to propose the best tie-in location of future wells in addition to providing first-pass flow assurance indications throughout the field's life and under different network configurations. The model enabled the facility engineers to keep the conditions of the surface facility within the optimized operating envelope throughout the field's lifetime.

Application of Digital Rock Analysis for Evaluation of Gas-Condensate Transport

2021 ◽  
Author(s):  
Oleg Dinariev ◽  
Nikolay Evseev
Keyword(s):  
Density Functional ◽  
Development Planning ◽  
Gas Condensate ◽  
Computational Method ◽  
Kinetic Properties ◽  
Pore Scale ◽  
Digital Rock ◽  
Compositional Model ◽  
Rock Analysis ◽  
Phase Mobility

Abstract The computational method for gas-condensate phase permeabilities is presented using digital rock analysis. The proposed method combines: a) construction of high-resolution tomographic images of the pore space; b) development of compositional model of a gas-condensate mixture at pore-scale including rheology, fluid-fluid and fluid-rock interfacial tension coefficients, and thermodynamic and kinetic properties of fluid phases; c) 3D pore-scale modeling of multiphase transport and interfacial chemical component exchange using the density functional hydrodynamics numerical simulator. This digital rock analysis workflow is applied to the gas-condensate transport at pore-scale. The numerical simulations are carried out using the 3D digital rock model constructed by X-ray microCT imaging of the rock pore structure. By specifying different gas and condensate fractions and injection rates it has been possible to obtain computationally 3D saturation distribution fields and the phase permeabilities. The results of 3D density functional hydrodynamic simulations provide the comprehensive description of gas-condensate mixture at pore-scale including hydrodynamic desaturation effects and phase transition kinetic phenomena. It is demonstrated that condensate distribution in pores, phase mobility thresholds and phase permeabilities are dependent on wettability properties and flow rates. It is shown that condensate composition in individual pores is also dynamically dependent on flow regimes. These results can be used in field development planning for the improved evaluation of condensate banking in the vicinity of production wells and condensate losses in the reservoir.

scholarly journals Evaluating the Challenges in Pressure – Volume – Temperature (PVT) Analysis of Gas Condensate Reservoirs

2020 ◽  
pp. 13-18
Author(s):  
Aniedi B. Usungedo ◽  
Julius U. Akpabio
Keyword(s):  
Gas Condensate ◽  
Production Performance ◽  
Prediction Algorithm ◽  
Pvt Properties ◽  
Volume Depletion ◽  
Volume Factor ◽  
Gas Condensate Reservoirs ◽  
Compositional Model ◽  
Compositional Modeling ◽  
Black Oil

Aims: The variations in production performances of the Black oil and compositional simulation models can be evaluated by simulating oil formation volume factor (Bo), gas formation volume factor (Bg), gas-oil ratio (Rs) and volatilized oil-gas ratio (Rv). The accuracy of these two models could be assessed. Methodology: To achieve this objective some basic parameters were keyed into matrix laboratory (MATLAB) using the symbolic mathematical toolbox to obtain accurate Pressure Volume Temperature (PVT) properties which were used in a production and systems analysis software to generate the production performance and hydrocarbon recovery estimation. Standard black oil PVT properties for a gas condensate reservoir was simulated by performing a series of flash calculations based on compositional modeling of the gas condensate fluid at the prescribed conditions through a constant volume depletion (CVD) path. These series of calculations will be carried out using the symbolic math toolbox. PVT property values obtained from both compositional modeling and black oil PVT prediction algorithm are incorporated to determine the production performance of each method for comparison. Results: The absolute open flow for the black oil PVT algorithm and the compositional model for the Rs value of 500 SCF/STB and Rs value of 720SCF/STB were 130,461 stb/d and 146,028 stb/d respectively showing a 10.66% incremental flow rate. Conclusion: In analyzing PVT properties for complex systems such as gas condensate reservoirs, the use of compositional modeling should be practiced. This will ensure accurate prediction of the reservoir fluid properties.

scholarly journals Reservoir Simulation Analysis of Pressure Depletion Performance in Gas-Condensate Reservoirs: Black-Oil and Compositional Approaches

2021 ◽  
pp. 119-137
Author(s):  
Akinsete O. Oluwatoyin ◽  
Anuka A. Agnes
Keyword(s):  
Relative Permeability ◽  
Reservoir Simulation ◽  
Gas Condensate ◽  
Productivity Index ◽  
Liquid Density ◽  
Gas Condensate Reservoirs ◽  
Compositional Model ◽  
Pressure Depletion ◽  
Black Oil ◽  
Black Oil Model

Pressure depletion in gas-condensate reservoirs create two-phase flow. It is pertinent to understand the behavior of gas-condensate reservoirs as pressure decline in order to develop proper producing strategies that would increase gas and condensate productivity. Eclipse 300 was used to simulate gas-condensate reservoirs, a base case model was created using both black-oil and compositional models. The effects of three Equation of States (EOS) incorporated into the models were analysed and condensate dropout effect on relative permeability was studied. Analysis of various case models showed that, gas production was maintained at 500MMSCF/D for about 18 and 12 months for black-oil and compositional models, respectively. However, the compositional model revealed that condensate production began after a period of two months at 50MSTB/D whereas for the black oil model, condensate production began immediately at 32MSTB/D. Comparison of Peng-Robinson EOS, Soave-Redlich-Kwong EOS and Schmidt Wenzel EOS gave total estimates of condensate production as 19MMSTB, 15MMSTB and 9MMSTB and initial values of gas productivity index as 320, 380 and 560, respectively. The results also showed that as condensate saturation increased, the relative permeability of gas decreased from 1 to 0 while the relative permeability of oil increased from 0.15 to 0.85. The reservoir simulation results showed that compositional model is better than black-oil model in modelling for gas-condensate reservoirs. Optimal production was obtained using 3-parameter Peng-Robinson and Soave-Redlich-Kwong EOS which provide a molar volume shift to prevent an underestimation of liquid density and saturations. Phase behaviour and relative permeability affect the behaviour of gas-condensate reservoirs.

scholarly journals Evaluation of black-oil PVT-model applicability for simulation of gas-condensate reservoirs

2020 ◽  
pp. 43-48
Author(s):  
O. V. Burachok ◽  
D. V. Pershyn ◽  
S. V. Matkivskyi ◽  
O. R. Kondrat
Keyword(s):  
Phase Transitions ◽  
Phase Equilibrium ◽  
Phase Behavior ◽  
Oil And Gas ◽  
Gas Condensate ◽  
Potential Yield ◽  
Model Application ◽  
Compositional Model ◽  
Black Oil ◽  
Black Oil Model

Creation of geological and simulation models is the necessary condition for decision making towards current development status, planning of well interventions, field development planning and forecasting. In case of isothermal process, for proper phase behavior and phase transitions two key approaches are used: a) simplified model of non-volatile oil, so called “black oil” model, in which each phase – oil, water and gas, are represented by respective component, and solution to fiow equations is based on finding the saturations and pressures in each numerical cell, and change of reservoir fiuid properties is defined in table form as a function of pressure; b) compositional model, in which based on equation of state, phase equilibrium is calculated for hydrocarbon and non-hydrocarbon components, and during fiow calculations, apart from saturations and pressures, oil and gas mixture is brought to phase equilibrium, and material balance is calculated for each component in gas and liquid phase. To account for components volatility, the classic black oil model was improved by adding to the formulation gas solubility and vaporized oil content. This allows its application for the majority of oil and gas reservoirs, which are far from critical point and in which the phase transitions are insignificant. Due to smaller number of variables, numerical solution is simpler and faster. But, considering the importance and relevance of increasing the production of Ukrainian gas and optimization of gas-condensate fields development, the issue of simplified black oil PVT-model application for phase behavior characterization of gas-condensate reservoirs produced under natural depletion depending on the liquid hydrocarbon’s potential yield. Comparative study results on evaluation of production performance of synthetic reservoir for different synthetically-generated reservoir fiuids with different С5+ potential yield is provided as plots and tables. Based on the results the limit of simplified black oil PVT-model application and the moment of transition to compositional model for more precise results could be defined.

A Generalized Compositional Approach for Reservoir Simulation

1983 ◽  
Vol 23 (05) ◽  
pp. 727-742 ◽  
Author(s):  
Larry C. Young ◽  
Robert E. Stephenson
Keyword(s):  
Enhanced Recovery ◽  
Gas Condensate ◽  
Reservoir Modeling ◽  
Pressure Equation ◽  
Compositional Modeling ◽  
Fluid Property ◽  
Black Oil ◽  
Fluid Properties ◽  
Newton Raphson ◽  
Raphson Method

A procedure for solving compositional model equations is described. The procedure is based on the Newton Raphson iteration method. The equations and unknowns in the algorithm are ordered in such a way that different fluid property correlations can be accommodated leadily. Three different correlations have been implemented with the method. These include simplified correlations as well as a Redlich-Kwong equation of state (EOS). The example problems considered area conventional waterflood problem,displacement of oil by CO, andthe displacement of a gas condensate by nitrogen. These examples illustrate the utility of the different fluid-property correlations. The computing times reported are at least as low as for other methods that are specialized for a narrower class of problems. Introduction Black-oil models are used to study conventional recovery techniques in reservoirs for which fluid properties can be expressed as a function of pressure and bubble-point pressure. Compositional models are used when either the pressure. Compositional models are used when either the in-place or injected fluid causes fluid properties to be dependent on composition also. Examples of problems generally requiring compositional models are primary production or injection processes (such as primary production or injection processes (such as nitrogen injection) into gas condensate and volatile oil reservoirs and (2) enhanced recovery from oil reservoirs by CO or enriched gas injection. With deeper drilling, the frequency of gas condensate and volatile oil reservoir discoveries is increasing. The drive to increase domestic oil production has increased the importance of enhanced recovery by gas injection. These two factors suggest an increased need for compositional reservoir modeling. Conventional reservoir modeling is also likely to remain important for some time. In the past, two separate simulators have been developed and maintained for studying these two classes of problems. This result was dictated by the fact that compositional models have generally required substantially greater computing time than black-oil models. This paper describes a compositional modeling approach paper describes a compositional modeling approach useful for simulating both black-oil and compositional problems. The approach is based on the use of explicit problems. The approach is based on the use of explicit flow coefficients. For compositional modeling, two basic methods of solution have been proposed. We call these methods "Newton-Raphson" and "non-Newton-Raphson" methods. These methods differ in the manner in which a pressure equation is formed. In the Newton-Raphson method the iterative technique specifies how the pressure equation is formed. In the non-Newton-Raphson method, the composition dependence of certain ten-ns is neglected to form the pressure equation. With the non-Newton-Raphson pressure equation. With the non-Newton-Raphson methods, three to eight iterations have been reported per time step. Our experience with the Newton-Raphson method indicates that one to three iterations per tune step normally is sufficient. In the present study a Newton-Raphson iteration sequence is used. The calculations are organized in a manner which is both efficient and for which different fluid property descriptions can be accommodated readily. Early compositional simulators were based on K-values that were expressed as a function of pressure and convergence pressure. A number of potential difficulties are inherent in this approach. More recently, cubic equations of state such as the Redlich-Kwong, or Peng-Robinson appear to be more popular for the correlation Peng-Robinson appear to be more popular for the correlation of fluid properties. SPEJ p. 727

scholarly journals Compositional Distributional Semantics with Syntactic Dependencies and Selectional Preferences

2021 ◽  
Vol 11 (12) ◽  
pp. 5743
Author(s):  
Pablo Gamallo
Keyword(s):  
English Language ◽  
State Of The Art ◽  
Current Work ◽  
Distributional Semantics ◽  
Compositional Model ◽  
Compositional Approach ◽  
Sentence Similarity ◽  
Selectional Preferences ◽  
Syntactic Dependencies ◽  
Compositional Distributional Semantics

This article describes a compositional model based on syntactic dependencies which has been designed to build contextualized word vectors, by following linguistic principles related to the concept of selectional preferences. The compositional strategy proposed in the current work has been evaluated on a syntactically controlled and multilingual dataset, and compared with Transformer BERT-like models, such as Sentence BERT, the state-of-the-art in sentence similarity. For this purpose, we created two new test datasets for Portuguese and Spanish on the basis of that defined for the English language, containing expressions with noun-verb-noun transitive constructions. The results we have obtained show that the linguistic-based compositional approach turns out to be competitive with Transformer models.

scholarly journals Binary Amplitude Reflection Gratings for X-ray Shearing and Hartmann Wavefront Sensors

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 536
Author(s):  
Kenneth A. Goldberg ◽  
Antoine Wojdyla ◽  
Diane Bryant
Keyword(s):  
Operating Conditions ◽  
Design Parameters ◽  
Wavefront Aberration ◽  
Light Sources ◽  
Wavefront Sensors ◽  
X Ray ◽  
New Class ◽  
Coherent Wave ◽  
Reflection Gratings ◽  
Dynamic Operating

New, high-coherent-flux X-ray beamlines at synchrotron and free-electron laser light sources rely on wavefront sensors to achieve and maintain optimal alignment under dynamic operating conditions. This includes feedback to adaptive X-ray optics. We describe the design and modeling of a new class of binary-amplitude reflective gratings for shearing interferometry and Hartmann wavefront sensing. Compact arrays of deeply etched gratings illuminated at glancing incidence can withstand higher power densities than transmission membranes and can be designed to operate across a broad range of photon energies with a fixed grating-to-detector distance. Coherent wave-propagation is used to study the energy bandwidth of individual elements in an array and to set the design parameters. We observe that shearing operates well over a ±10% bandwidth, while Hartmann can be extended to ±30% or more, in our configuration. We apply this methodology to the design of a wavefront sensor for a soft X-ray beamline operating from 230 eV to 1400 eV and model shearing and Hartmann tests in the presence of varying wavefront aberration types and magnitudes.

Impact of Operating Conditions and Design Parameters on Gas Turbine Hot Section Creep Life

2010 ◽  
Author(s):  
S. Eshati ◽  
M. F. Abdul Ghafir ◽  
P. Laskaridis ◽  
Y. G. Li
Keyword(s):  
Gas Turbines ◽  
Performance Model ◽  
Operating Conditions ◽  
Creep Model ◽  
Design Parameters ◽  
Gas Temperature ◽  
Creep Life ◽  
Cooling Effectiveness ◽  
Radial Temperature ◽  
The Impact

This paper investigates the relationship between design parameters and creep life consumption of stationary gas turbines using a physics based life model. A representative thermodynamic performance model is used to simulate engine performance. The output from the performance model is used as an input to the physics based model. The model consists of blade sizing model which sizes the HPT blade using the constant nozzle method, mechanical stress model which performs the stress analysis, thermal model which performs thermal analysis by considering the radial distribution of gas temperature, and creep model which using the Larson-miller parameter to calculate the lowest blade creep life. The effect of different parameters including radial temperature distortion factor (RTDF), material properties, cooling effectiveness and turbine entry temperatures (TET) is investigated. The results show that different design parameter combined with a change in operating conditions can significantly affect the creep life of the HPT blade and the location along the span of the blade where the failure could occur. Using lower RTDF the lowest creep life is located at the lower section of the span, whereas at higher RTDF the lowest creep life is located at the upper side of the span. It also shows that at different cooling effectiveness and TET for both materials the lowest blade creep life is located between the mid and the tip of the span. The physics based model was found to be simple and useful tool to investigate the impact of the above parameters on creep life.

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