APPLICATION OF THE BLACK OIL PVT REPRESENTATION TO SIMULATION OF GAS CONDENSATE RESERVOIR PERFORMANCE

1987 ◽  
Vol 27 (1) ◽  
pp. 370
Author(s):  
W.H. Goldthorpe ◽  
J.K. Drohm
Keyword(s):  
Oil And Gas ◽  
Volatile Oil ◽  
Gas Condensate ◽  
Phase Behaviour ◽  
Dew Point ◽  
Pressure Drops ◽  
Gas Condensate Reservoirs ◽  
Reservoir Performance ◽  
Black Oil ◽  
Condensate Reservoir

Special attention must be paid to the generation of PVT parameters when applying conventional black oil reservoir simulators to the modelling of volatile oil and gas-condensate reservoirs. In such reservoirs phase behaviour is an important phenomenon and common approaches to approximating this, via the black oil PVT representation, introduce errors that may result in prediction of incorrect recoveries of surface gas and condensate. Further, determination of production tubing pressure drops for use in such simulators is also prone to errors. These affect the estimation of well potentials and reservoir abandonment pressures.Calculation of black oil PVT parameters by the method of Coats (1985) is shown to be preferred over conventional approaches, although the PVT parameters themselves lose direct physical meaning. It is essential that a properly tuned equation of state be available for use in conjunction with experimental data.Production forecasting based on simulation output requires further processing in order to translate the black oil surface phase fluxes into products such as sales gas, LPG and condensate. For gas-condensate reservoirs, such post-processing of results from the simulation of depletion or cycling above the dew point is valid. In principle it is invalid for cycling below the dew point but in practice it can still provide useful information.

Determination of Bubble-Point and Dew-Point Pressure Without a Visual Cell

2014 ◽  
Author(s):  
R.. Hosein ◽  
R.. Mayrhoo ◽  
W. D. McCain
Keyword(s):  
Oil And Gas ◽  
Saturation Pressure ◽  
Volatile Oil ◽  
Phase Region ◽  
Gas Condensate ◽  
Dew Point ◽  
Bubble Point ◽  
Point Pressure ◽  
Dew Point Pressure

Abstract Bubble-point and dew-point pressures of oil and gas condensate reservoir fluids are used for planning the production profile of these reservoirs. Usually the best method for determination of these saturation pressures is by visual observation when a Constant Mass Expansion (CME) test is performed on a sample in a high pressure cell fitted with a glass window. In this test the cell pressure is reduced in steps and the pressure at which the first sign of gas bubbles is observed is recorded as bubble-point pressure for the oil samples and the first sign of liquid droplets is recorded as the dew-point pressure for the gas condensate samples. The experimental determination of saturation pressure especially for volatile oil and gas condensate require many small pressure reduction steps which make the observation method tedious, time consuming and expensive. In this study we have extended the Y-function which is often used to smooth out CME data for black oils below the bubble-point to determine saturation pressure of reservoir fluids. We started from the initial measured pressure and volume and by plotting log of the extended Y function which we call the YEXT function, with the corresponding pressure, two straight lines were obtained; one in the single phase region and the other in the two phase region. The point at which these two lines intersect is the saturation pressure. The differences between the saturation pressures determined by our proposed YEXT function method and the observation method was less than ± 4.0 % for the gas condensate, black oil and volatile oil samples studied. This extension of the Y function to determine dew-point and bubble-point pressures was not found elsewhere in the open literature. With this graphical method the determination of saturation pressures is less tedious and time consuming and expensive windowed cells are not required.

scholarly journals Wettability Alteration of Sandstone by Chemical Treatments

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Yan-ling Wang ◽  
Li Ma ◽  
Bao-jun Bai ◽  
Guan-cheng Jiang ◽  
Jia-feng Jin ◽  
...  
Keyword(s):  
Contact Angle ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Gas Production ◽  
Gas Condensate ◽  
Dew Point ◽  
Wettability Alteration ◽  
Pressure Drops ◽  
Gas Condensate Reservoirs ◽  
Chemical Treatments

Liquid condensation in the reservoir near a wellbore may kill gas production in gas-condensate reservoirs when pressure drops lower than the dew point. It is clear from investigations reported in the literature that gas production could be improved by altering the rock wettability from liquid-wetness to gas-wetness. In this paper, three different fluorosurfactants FG1105, FC911, and FG40 were evaluated for altering the wettability of sandstone rocks from liquid-wetting to gas-wetting using contact angle measurement. The results showed that FG40 provided the best wettability alteration effect with a concentration of 0.3% and FC911 at the concentration of 0.3%.

scholarly journals Gas-Wetting Alteration by Fluorochemicals and Its Application for Enhancing Gas Recovery in Gas-Condensate Reservoirs: A Review

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4591 ◽  
Author(s):  
Jiafeng Jin ◽  
Jinsheng Sun ◽  
Kesheng Rong ◽  
Kaihe Lv ◽  
Tuan A. H. Nguyen ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Current Knowledge ◽  
Gas Condensate ◽  
Dew Point ◽  
Wettability Alteration ◽  
Gas Reservoirs ◽  
Gas Recovery ◽  
Wellbore Pressure ◽  
Condensate Reservoir ◽  
The Difference

Gas-wetting alteration is a versatile and effective approach for alleviating liquid-blockage that occurs when the wellbore pressure of a gas-condensate reservoir drops below the dew point. Fluorochemicals are of growing interest in gas-wetting alteration because of their high density of fluorine groups and thermal stability, which can change the reservoir wettability into more favorable conditions for liquids. This review aims to integrate the overlapping research between the current knowledge in organic chemistry and enhanced oil and gas recovery. The difference between wettability alteration and gas-wetting alteration is illustrated, and the methods used to evaluate gas-wetting are summarized. Recent advances in the applications of fluorochemicals for gas-wetting alteration are highlighted. The mechanisms of self-assembling adsorption layers formed by fluorochemicals with different surface morphologies are also reviewed. The factors that affect the gas-wetting performance of fluorochemicals are summarized. Meanwhile, the impacts of gas-wetting alteration on the migration of fluids in the pore throat are elaborated. Furthermore, the Wenzel and Cassie-Baxter theories are often used to describe the wettability model, but they are limited in reflecting the wetting regime of the gas-wetting surface; therefore, a wettability model for gas-wetting is discussed. Considering the promising prospects of gas-wetting alteration, this study is expected to provide insights into the relevance of gas-wetting, surface morphology and fluorochemicals, further exploring the mechanism of flow efficiency improvement of fluids in unconventional oil and gas reservoirs.

scholarly journals Unsteady-state conditions of producing wells at of the Urengoy oil and gas condensate field influences their efficiency

2019 ◽  
pp. 47-53
Author(s):  
Vladislav V. Inyakin ◽  
Semen F. Mulyavin ◽  
Igor A. Usachev
Keyword(s):  
Oil And Gas ◽  
Gas Condensate ◽  
Dew Point ◽  
Unsteady State ◽  
Pressure Drops ◽  
Well Efficiency ◽  
Point Pressure ◽  
Dew Point Pressure ◽  
Liquid Condensate ◽  
Bottomhole Pressure

The development of oil and gas condensate fields is accompanied by phase transformations of reservoir mixtures, i.e. the when the bottomhole pressure drops below the dew point pressure, the liquid condensate becomes versatile and enters the gas phase. Retrograde condensate leads to a decrease in phase permeability in the bottomhole. As a result, it also leads to a decrease in production levels is reduced both by gas and natural gas liquids. The article considers this challenge and its possible solutions by the method of unsteady-state conditions well efficiency, on which the hydraulic fracturing was carried out. The issue of well efficiency is urgent in conditions abnormally high reservoir pressure and considerable condensate yield.

scholarly journals Numerical Well Test Analysis of Condensate Dropout Effects in Dual-Permeability Model of Naturally Fractured Gas Condensate Reservoirs: Case Studies in the South of Iran

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Mohsen Safari-Beidokhti ◽  
Abdolnabi Hashemi ◽  
Reza Abdollahi ◽  
Hamed Hematpur ◽  
Hamid Esfandyari
Keyword(s):  
Gas Condensate ◽  
Dew Point ◽  
Well Test ◽  
Well Test Analysis ◽  
Permeability Model ◽  
Test Analysis ◽  
Pressure Drops ◽  
Gas Condensate Reservoirs ◽  
Bottom Hole ◽  
Naturally Fractured

Naturally fractured reservoirs (NFR) represent an important percentage of worldwide hydrocarbon reserves and production. The performance of naturally fractured gas condensate reservoirs would be more complicated regarding both rock and fluid effects. In contrast to the dual-porosity model, dual-porosity/dual-permeability (dual-permeability) model is considered as a modified model, in which flow to the wellbore occurs through both matrix and fracture systems. Fluid flow in gas condensate reservoirs usually demonstrates intricate flow behavior when the flowing bottom-hole pressure falls below the dew point. Accordingly, different regions with different characteristics are formed within the reservoir. These regions can be recognized by pressure transient analysis. Consequently, distinguishing between reservoir effects and fluid effects is challenging in these specific reservoirs and needs numerical simulation. The main objective of this paper is to examine the effect of condensate banking on the pressure behavior of lean and rich gas condensate NFRs through a simulation approach. Subsequently, evaluation of early-time characteristics of the pressure transient data is provided through a single well compositional simulation model. Then, drawdown, buildup, and multirate tests are conducted to establish the condition in which the flowing bottom-hole pressure drops below the dew point causing retrograde condensation. The simulation results are confirmed through well test analysis in both Iranian naturally fractured rich and lean gas condensate fields. Interpretations of simulation analysis revealed that the richer gas is more prone to condensation. When the pressure drops below the dew point, the pressure derivative curves in the rich gas system encounter a more shift to the right, and the trough becomes more pronounced as compared to the lean one.

scholarly journals Investigating the Behavior of Low Permeable Lean and Rich Gas Condensate Reservoirs

2018 ◽  
Vol 8 (6) ◽  
Author(s):  
Sohail Nawab ◽  
Abdul Haque Tunio ◽  
Aftab Ahmed Mahesar ◽  
Imran Ahmed Hullio
Keyword(s):  
Gas Condensate ◽  
Dew Point ◽  
Reservoir Rock ◽  
New Paradigm ◽  
Gas Condensate Reservoirs ◽  
Gas Recovery ◽  
Condensate Reservoir ◽  
Compositional Simulator ◽  
Point Pressure ◽  
Dew Point Pressure

The producing behavior of low permeable gas condensate reservoirs is dramatically different from that of conventional reservoirs and requires a new paradigm to understand and interpret it. As the reservoir pressure initiates to decline and reaches to dew point pressure of the fluid then the condensate is formed and causes the restriction in the flow in the reservoir rock which results, decrease in the well productivity near the wellbore vicinity which is known as condensate blockage. Henceforward, it is better to understand the behavior of the low permeable lean and rich gas condensate reservoirs by several perspectives through the compositional simulator. Besides this study involves the following perspectives; the increase in the number of wells and by varying the flowrate of the gas in six different cases for low permeable lean and rich gas condensate reservoirs. It was concluded that low permeable lean and rich gas condensate reservoirs have similar gas recovery factors. Whereas the CRF plays inverse behavior for both reservoirs as CRF is maximum for lean gas condensate at single producing well but for rich gas condensate reservoir the CRF increases as the number of wells escalates. Additionally, in second effect the varying gas flowrates lean gas condensate reservoir has maximum CRF at lesser flowrate but it is opposite for the low permeable rich gas condensate reservoir, for single or two producing wells the flowrate effect plays but when the number of wells is increasing there is not any significant change in CRF

Monitoring the composition of gas condensate well streams based on samples taken from multiphase flow meters

2021 ◽  
pp. 127-139
Author(s):  
E. A. Gromova ◽  
S. A. Zanochuev
Keyword(s):  
Multiphase Flow ◽  
Oil And Gas ◽  
Gas Condensate ◽  
Flow Meters ◽  
Gas Condensate Reservoirs ◽  
Reliable Estimation ◽  
Development Control ◽  
Hydrocarbon System ◽  
Labor Consuming

The article highlights the relevance of reliable estimation of the composition and properties of reservoir gas during the development of gas condensate fields and the complexity of the task for reservoirs containing zones of varying condensate content. The authors have developed a methodology that allows monitoring the composition of gas condensate well streams of similar reservoirs. There are successful examples of the approach applied in Achimov gas condensate reservoirs at the Urengoy oil and gas condensate field. The proposed approach is based on the use of the so-called fluid factors, which are calculated on the basis of the known component compositions of various flows of the studied hydrocarbon system. The correlation between certain "fluid factors" and the properties of reservoir gas (usually determined by more labor-consuming methods) allows one to quickly obtain important information necessary to solve various development control tasks.

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