Wet Gas Performance Analysis

2006 ◽  
Author(s):  
O̸yvind Hundseid ◽  
Lars E. Bakken
Keyword(s):  
Performance Analysis ◽  
Performance Prediction ◽  
Volumetric Flow Rate ◽  
Phase Changes ◽  
Direct Integration ◽  
Compression Performance ◽  
Wet Gas ◽  
Gas Compression ◽  
Performance Predictions ◽  
Fluid Properties

The growing interest in wet gas compressors calls for accurate methods for performance prediction. Present evaluation methods for compressor and pump performance fail when evaluating the compression of gases containing liquid. Gas compression performance predictions given in ASME PTC-10-97 and ISO 5318 are based on the method John M. Schultz proposed in 1962. This method assumes a polytropic compression path and is based on averaged gas properties of inlet and outlet condition. The polytropic compression path is defined by keeping pvn constant, where n is constant along the compression path. When employing the Schultz method there is a challenge in defining the polytropic constant. This is seen in cases where dry gas compressors are exposed to wet components and compressor efficiency estimates exceed 100%. Today’s computer technology makes a direct integration of the polytropic head (∫vdp) possible where actual fluid properties along the compression path are included. Phase changes along the compression path are included with this method. This enables a detailed prediction to be made of the actual volumetric flow rate for the various compressor stages. This paper reports the implementation of the direct integration procedure for wet gas performance prediction. The procedure enables generic wet gas compression to be studied which forms the foundation for performance analysis with variations in operation at conditions and fluid components and properties.

Wet Gas Performance of a Single Stage Centrifugal Compressor

2008 ◽  
Author(s):  
O̸yvind Hundseid ◽  
Lars E. Bakken ◽  
Trond G. Gru¨ner ◽  
Lars Brenne ◽  
Tor Bjo̸rge
Keyword(s):  
Performance Analysis ◽  
Centrifugal Compressor ◽  
Single Stage ◽  
Water Mixture ◽  
Performance Parameters ◽  
Operating Range ◽  
Wet Gas ◽  
Gas Compression ◽  
Compressor Performance ◽  
The Impact

This paper evaluates the performance analysis of wet gas compression. It reports the performance of a single stage gas centrifugal compressor tested on wet gas. These tests were performed at design operating range with real hydrocarbon mixtures. The gas volume fraction was varied from 0.97 to 1.00, with alternation in suction pressure. The range is representative for many of the gas/condensate fields encountered in the North Sea. The machine flow rate was varied to cover the entire operating range. The compressor was also tested on a hydrocarbon gas and water mixture to evaluate the impact of liquid properties on performance. No performance and test standards currently exist for wet gas compressors. To ensure nominated flow under varying fluid flow conditions, a complete understanding of compressor performance is essential. This paper gives an evaluation of real hydrocarbon multiphase flow and performance parameters as well as a wet gas performance analysis. The results clearly demonstrate that liquid properties influence compressor performance to a high degree. A shift in compressor characteristics is observed under different liquid level conditions. The results in this paper confirm the need for improved fundamental understanding of liquid impact on wet gas compression. The evaluation demonstrates that dry gas performance parameters are not applicable for wet gas performance analysis. Wet gas performance parameters verified against results from the tested compressor is presented.

A Revised Compressor Polytropic Performance Analysis

2006 ◽  
Author(s):  
O̸yvind Hundseid ◽  
Lars E. Bakken ◽  
Tor Helde
Keyword(s):  
Equation Of State ◽  
Gas Production ◽  
Phase Changes ◽  
Direct Integration ◽  
Compression Process ◽  
Liquid Phases ◽  
Wet Gas ◽  
Direct Integration Method ◽  
Compressor Performance ◽  
Gas Properties

The compressor polytropic head and efficiency analysis are based on the assumption that the compression process follows the path of a constant polytropic exponent n. Both the ASME PTC10-97 and the ISO 5389 refer to the polytropic analysis by John M. Schultz. The procedure utilizes a head correction factor and two compressibility functions to obtain a solution of the integral Δhp = ∫vdp. Present computer technology renders possible a direct integration of the compression path where the variation in actual gas properties along the path is included. This method eliminates the averaging of gas properties which the Schultz procedure includes. This paper reports deviation in compressor performance using the Schultz procedure with different average gas properties. The implementation of a direct integration procedure, employing actual gas properties from the new GERG-2004 equation of state, is given. The GERG-2004 equation of state has proven to give accurate density values both in the vapour and liquid phases. Depending on how the polytropic compression analysis is implemented, the work has revealed up to 4% deviation in polytropic head and efficiency for some specific compressors. This adds an extra uncertainty in compressor performance verification. Even though the API 617 allows up to 4% deviation, some compressors have to meet a more stringent demand, for instance 2% at the Sno̸hvit LNG plant. Future challenges within oil and natural gas production are related to wet gas compressors. The present paper points out the advantages in using a direct integration method for wet gas performance predictions as this takes phase changes along the compression path into account.

Wet Gas Compression: Test Conditions and Similitude

2017 ◽  
Author(s):  
Dagfinn Mæland ◽  
Lars E. Bakken
Keyword(s):  
Oil Recovery ◽  
Performance Prediction ◽  
Oil And Gas ◽  
Mechanical Design ◽  
Performance Testing ◽  
Volume Ratio ◽  
Centrifugal Compressors ◽  
Wet Gas ◽  
Gas Compression ◽  
Compressor Design

Wet gas compression of gas/condensate/water provides a business opportunity for oil and gas producers. There are several opportunities of particular note: 1) As well tail-end production commences, the installation of sub-sea compressors will provide enhanced oil recovery and, if the subsea compressor is capable of handling liquids, the subsea process complexity can be dramatically reduced, thus decreasing capital investments and possibly operational costs. 2) Topside and Onshore projects can also be dramatically simplified. This is the case for both new installations and modification projects for which wet gas compression is a suitable solution. However, there are several challenges that need to be addressed before wet gas compression, by means of centrifugal compressors, can be considered as a robust commercial solution for future projects. This relates to the robustness of the mechanical design, effects on electrical systems, and issues related to performance. This paper will focus on challenges related to performance prediction and testing. For conventional dry gas compressor design, performance prediction is usually undertaken by the compressor manufacturer, utilising in-house know-how in impeller design and selection. This specialised knowledge is potentially unsuitable for predicting wet gas performance in the design phase; hence, a wet gas compressor design may not meet design requirements specified by the customer. It is typical that agreements on performance testing of centrifugal compressors state that these are to be conducted according to an international standard such as ASME PTC10 or ISO 5389. These standards require that the compressed gas is dry. However, for wet gas compressors, no such internationally established standards exist for performance evaluation. Several of the requirements stipulated in the standards are challenging to apply to wet conditions and they do not ensure similar conditions. Such parameters including the maximum permissible deviation in the specific volume ratio, Mach number and Reynolds number. It is clear that the path towards a standard for wet gas performance testing will require a substantial amount of effort in order to establish new requirements related to wet gas similarity. Based on wet gas compressor test experience, challenges and requirements related to low pressure inert fluid, compared with full pressure actual fluid tests, are analysed and discussed.

Optimal Structure Design and Performance Analysis of Multiphase Twin-screw Pump for Wet Gas Compression

2021 ◽  
Vol 14 (2) ◽  
pp. 208-219
Author(s):  
Xuejing Zhang ◽  
Junhu Yang ◽  
Wenkai Bei ◽  
Wei Han ◽  
Canyang Chen ◽  
...  
Keyword(s):  
Performance Analysis ◽  
Structure Design ◽  
Optimal Structure ◽  
Screw Pump ◽  
Wet Gas ◽  
Gas Compression ◽  
Twin Screw ◽  
And Performance

scholarly journals Reservoir Performance Prediction using Integrated Production Modelling (MBAL Software)

2019 ◽  
Vol 8 (4) ◽  
pp. 1484-1489
Keyword(s):  
Performance Prediction ◽  
History Matching ◽  
Material Balance ◽  
Development Planning ◽  
Reservoir Rock ◽  
Rock Properties ◽  
Production Operation ◽  
Gas Field ◽  
Reservoir Performance ◽  
Fluid Properties

Reservoir performance prediction is important aspect of the oil & gas field development planning and reserves estimation which depicts the behavior of the reservoir in the future. Reservoir production success is dependent on precise illustration of reservoir rock properties, reservoir fluid properties, rock-fluid properties and reservoir flow performance. Petroleum engineers must have sound knowledge of the reservoir attributes, production operation optimization and more significant, to develop an analytical model that will adequately describe the physical processes which take place in the reservoir. Reservoir performance prediction based on material balance equation which is described by Several Authors such as Muskat, Craft and Hawkins, Tarner’s, Havlena & odeh, Tracy’s and Schilthuis. This paper compares estimation of reserve using dynamic simulation in MBAL software and predictive material balance method after history matching of both of this model. Results from this paper shows functionality of MBAL in terms of history matching and performance prediction. This paper objective is to set up the basic reservoir model, various models and algorithms for each technique are presented and validated with the case studies. Field data collected related to PVT analysis, Production and well data for quality check based on determining inconsistencies between data and physical reality with the help of correlations. Further this paper shows history matching to match original oil in place and aquifer size. In the end conclusion obtained from different plots between various parameters reflect the result in history match data, simulation result and Future performance of the reservoir system and observation of these results represent similar simulation and future prediction plots result.

scholarly journals A Review on the Application of Multiphase Twin Screw Pump as a Downhole Wet Gas Compressor to Improve Gas Wells Recovery Factor

2021 ◽  
Vol 15 ◽  
pp. 223-232
Author(s):  
Sharul Sham Dol ◽  
Niraj Baxi ◽  
Mior Azman Meor Said
Keyword(s):  
Volume Fraction ◽  
Energy Industry ◽  
Gas Wells ◽  
Screw Pump ◽  
Research Activities ◽  
Wet Gas ◽  
Gas Compression ◽  
Twin Screw ◽  
Gas Volume Fraction ◽  
Gas Volume

By introducing a multiphase twin screw pump as an artificial lifting device inside the well tubing (downhole) for wet gas compression application; i.e. gas volume fraction (GVF) higher than 95%, the unproductive or commercially unattractive gas wells can be revived and made commercially productive once again. Above strategy provides energy industry with an invaluable option to significantly reduce greenhouse gas emissions by reviving gas production from already existing infrastructure thereby reducing new exploratory and development efforts. At the same time above strategy enables energy industry to meet society’s demand for affordable energy throughout the critical energy transition from predominantly fossil fuels based resources to hybrid energy system of renewables and gas. This paper summarizes the research activities related to the applications involving multiphase twin screw pump for gas volume fraction (GVF) higher than 95% and outlines the opportunity that this new frontier of multiphase fluid research provides. By developing an understanding and quantifying the factors that influence volumetric efficiency of the multiphase twin screw pump, the novel concept of productivity improvement by a downhole wet gas compression using above technology can be made practicable and commercially more attractive than other production improvement strategies available today. Review and evaluation of the results of mathematical and experimental models for multiphase twin screw pump for applications with GVF of more than 95% has provided valuable insights in to multiphase physics in the gap leakage domains of pump and this increases confidence that novel theoretical concept of downhole wet gas compression using multiphase twin screw pump that is described in this paper, is practically achievable through further research and improvements.

Laminar Flow of Non-Newtonian Fluids in an Eccentric Annulus

1975 ◽  
Vol 97 (2) ◽  
pp. 498-506 ◽  
Author(s):  
T. L. Guckes
Keyword(s):  
Numerical Procedure ◽  
Volumetric Flow Rate ◽  
Newtonian Flow ◽  
Bingham Plastic ◽  
Eccentric Annulus ◽  
Bipolar Coordinates ◽  
Special Cases ◽  
Fluid Properties ◽  
Finite Difference Solution ◽  
Plastic Fluids

The volumetric flow rate for the steady flow of power-law and Bingham-plastic fluids in eccentric annuli is presented as a series of dimensionless plots. The plots cover a broad range of fluid properties, pipe diameters, eccentricity, and pressure drop. These relationships were obtained by numerically integrating the velocity profile resulting from a finite difference solution of the equations of continuity and motion after transformation into bipolar coordinates. The numerical procedure was verified by comparing calculations with previously published results for the special cases of Newtonian flow in an eccentric annulus and non-Newtonian flow in a concentric annulus and with limited experimental data for Bingham-plastic flow in an eccentric annulus.

Advances in Subsea Wet Gas Compression Technologies

2011 ◽  
Author(s):  
Mads Hjelmeland ◽  
Arne B. Olsen ◽  
Rudi Marjohan
Keyword(s):  
Wet Gas ◽  
Gas Compression
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