Study of Use of Supercritical CO2 to Enhance Gas Recovery and its Interaction With Carbonate Reservoirs

2013 ◽  
Author(s):  
Hicham El Hajj ◽  
Uchenna Odi ◽  
Anuj Gupta
Keyword(s):  
Carbonate Reservoir ◽  
Dew Point ◽  
Productivity Index ◽  
Gas Recovery ◽  
Carbonate Formation ◽  
Wet Gas ◽  
Point Pressure ◽  
Condensate Blockage ◽  
Simulation Results ◽  
Dew Point Pressure

It is well known that with continued production from wet gas reservoirs, the reservoir pressure eventually falls below the dew point pressure leading to condensation and loss of gas productivity in the reservoir. The concept of simultaneously injecting CO2 in a gas reservoir for long term storage while at the same time accelerating production of the natural gas is intriguing and promising. CO2 may also interact with carbonate matrix by changing porosity and permeability of the host rock; this is true for reservoirs that are found in the Gulf Region. To maintain field gas production targets, operators routinely set the bottom hole pressure below the dew point pressure which results in condensate blockage. Injecting CO2 can delay the onset of condensate blockage by reducing the dew point pressure of the condensate blockage zone. The approach illustrated, utilizes CO2 to delay the onset of condensate blockage. Factors such as improved effusion were analyzed to justify the use of CO2 for wellbore condensate removal and enhanced gas recovery (EGR). Experimental verification of a new method of determining dew point pressures for wet gas fluids is presented in this work and compared to simulation results. Core floods experiments with carbon dioxide were conducted in a core sample analogue to carbonate at reservoir conditions in order to study the interaction between CO2 and carbonate reservoir. CO2 sequestration in carbonate formation was evaluated by XRF and AFM. Experimental and simulation results show increases in productivity index after CO2 injection. Increases in productivity index were caused by CO2 evaporating the condensate blockage. Condensate vaporization was caused by CO2 reducing the dew point pressure of the condensate. Carbonate aging in presence of CO2 shows two mechanism of CO2 trapping which are dissolution and mineralization.

A New Correlation to Predict Dew Point Pressure in Wet Gas Reservoirs

2014 ◽  
Vol 39 (11) ◽  
pp. 8341-8346 ◽  
Author(s):  
Ehsan Ghanaatpisheh ◽  
Hosein Vahdani ◽  
Kamal Bolandparvaz Jahromi
Keyword(s):  
Dew Point ◽  
Gas Reservoirs ◽  
New Correlation ◽  
Wet Gas ◽  
Point Pressure ◽  
Dew Point Pressure

scholarly journals Impact of Hydraulic Fracturing on Productivity of Gas Condensate Wells

2020 ◽  
Vol 8 (6) ◽  
pp. 1202-1208
Keyword(s):  
Hydraulic Fracture ◽  
Gas Condensate ◽  
Dew Point ◽  
Darcy Flow ◽  
Productivity Index ◽  
Reservoir Pressure ◽  
Pressure Drops ◽  
Compositional Simulator ◽  
Point Pressure ◽  
Dew Point Pressure

Having an increase in the discovery of gas reservoirs all over the world, the most common problem related to gas condensate wells while producing below dew point condition is condensate banking. As the bottom hole pressure drops below the dew point, the liquid starts to exist and condensate begins to accumulate. Relative permeability of gas will be reduced as well as the well productivity will start to decline. The effect of applying a hydraulic fracture to gas condensate wells is the main objective of this paper. A compositional simulator is utilized to investigate the physical modifications that could happen to gas and condensate during the production life of an arbitrary well. Performing a good designed hydraulic fracture to a gas condensate well typically enhances the production of such well. This increase depends basically on certain factors such as non-Darcy flow, capillary number and capillary pressure. Non-Darcy flow has a dominant impact on gas and condensate productivity index after performing a hydraulic fracture as the simulator indicates. The enhancement of gas and condensate production can be obtained for gas condensate reservoirs in which the reservoir pressure is above or around the dew point pressure to have a margin for the pressure to decline with time and also eliminate the probability of forming condensate in the reservoir. On the other hand if the reservoir pressure is below the dew point pressure, there will be definitely a condensate in the reservoir and a specific design for the hydraulic fracture is a must to get the required enhancement in the production.

scholarly journals Condensate banking removal: study on ultrasonic amplitude effect

2021 ◽  
Author(s):  
Aieshah Ainuddin ◽  
Nabilla Afzan Abdul Aziz ◽  
Nor Akmal Affandy Mohamed Soom
Keyword(s):  
Negative Impact ◽  
Cost Effective ◽  
Gas Condensate ◽  
Drop Out ◽  
Dew Point ◽  
Productivity Index ◽  
Sweep Efficiency ◽  
Condensate Reservoir ◽  
Point Pressure ◽  
Dew Point Pressure

AbstractHydrocarbons in a gas condensate reservoir consist of a wide variety of molecules which will react varyingly with the change of pressure inside the reservoir and wellbore. The presence of heavier ended hydrocarbons such as C5 and above, condensate banking will occur as pressure depletes. Pressure drop below dew point pressure causes condensate buildup which will give a negative impact in the productivity index of a gas condensate reservoir. Gas condensate reservoirs experience liquid drop out when pressure depletion reaches below dew point pressure. This occurrence will eventually cause condensate banking over time of production where condensate builds up in pore spaces of near-wellbore formations. Due to increase in condensate saturation, gas mobility is reduced and causes reduction of recoverable hydrocarbons. Instead of remediating production loss by using unsustainable recovery techniques, sonication is used to assist the natural flow of a gas condensate reservoir. This study aims to evaluate the effects of various ultrasonic amplitudes on condensate removal in a heterogenous glass pack in flowing conditions with varying exposure durations. Experiments were conducted by using n-Decane and a glass pack to represent condensate banking and near-wellbore area. Carbon dioxide was flowed through the pack to represent flowing gas from the reservoir after sonication of 10%, 50% and 100% amplitudes (20 kHz and 20 Watts). Analysis of results shows recovery of up to 17.36% and an areal sweep efficiency increase in 24.33% after sonication of 100% amplitude for 120 min due to reduction in viscosity. It was concluded that sweeping efficiency and reciprocal mobility ratio are increased with sonication of 100% amplitude for 120 min. This indicates that mobility of n-Decane is improved after sonication to allow higher hydrocarbon liquid production. Insights into the aspects of the mechanical wave are expected to contribute to a better understanding of tuning the sonic wave, to deliver remarkable results in a closed solid and fluid system. This form of IOR has not only proved to be an effective method to increase productivity in gas condensate wells, but it is also an environmentally sustainable and cost-effective method.

scholarly journals Hydraulic Fracturing Designs For Low Permeability Gas Condensate Reservoirs Having Lean and Rich Condensate Compositions

2017 ◽  
Vol 3 (3) ◽  
pp. 9
Author(s):  
Karanthakarn Mekmok ◽  
Jirawat Chewaroungroaj
Keyword(s):  
Hydraulic Fracturing ◽  
Gas Condensate ◽  
Dew Point ◽  
Well Productivity ◽  
Fracture Conductivity ◽  
Gas Condensate Reservoirs ◽  
Point Pressure ◽  
Condensate Blockage ◽  
Dew Point Pressure ◽  
Saturation Profile

Gas condensate reservoirs have been challenging many researchers in petroleum industry for decades because of their complexities in flow behavior. After dew point pressure is reached, gas condensate will drop liquid out and increase liquid saturation near wellbore vicinity called condensate banking or condensate blockage. Hydraulic fracturing in horizontal direction has been proved to be a reliable method to mitigate condensate blockage and increase productivity of gas condensate well by means of pressure redistribution in the near wellbore vicinity. In this paper the parameters of dimensionless fracture conductivity and Stimulated Reservoir Volume (SRV) designs of lean and rich condensate compositions are studied. Well productivity and saturation profile of each design had been observed. The results from this study indicate that the higher dimensionless fracture conductivity gives the higher well productivity in every studied parameter in lean condensate composition. However, in rich condensate composition shows different trend of results because it has higher heavy ends (C7+) that drop into liquid easier once pressure falls below dew point pressure. The maximum number of fracture and fracture permeability can be recognized in the study of rich condensate. In the study of SRV indicates that number of fracture is superior to fracture width in both gas and condensate productivity. Moreover, performing hydraulic fracturing can decrease pressure drawdown, production time and liquid dropout which leads to the mitigation of condensate banking near wellbore that can be recognized in the study of condensate saturation profile.

Software Simulation and Experimental Study on Wax Deposition Pattern of Deep Condensate Gas

2019 ◽  
Author(s):  
Jie Wang ◽  
Fujian Zhou ◽  
Erdong Yao ◽  
Fan Fan ◽  
Lishan Yuan ◽  
...  
Keyword(s):  
Solid Phase ◽  
Dew Point ◽  
Wax Deposition ◽  
Deposition Pattern ◽  
Gas Reservoir ◽  
Software Simulation ◽  
Point Pressure ◽  
Simulation Results ◽  
Temperature And Pressure ◽  
Dew Point Pressure

Abstract The Bozi block of Tarim Oilfield is a typical tight sand condensate gas reservoir with serious wax plugging issue. It is necessary to study the phase behavior and the wax deposition pattern of well fluids in Bozi gas reservoir, which provides the phase enveloping diagram of the condensate gas and can help to control the paraffin deposition. In this study, the PVT tester and self-designed microscopic solid deposition tester are used to get the phase enveloping curve of the condensate gas, which is combined with software simulation results and production data of Bozi 104 well to analyze wax deposition from formation to wellbore, wellbore to ground and surface pipeline. The main conclusions and suggestions are as follows: with different temperature and pressure, condensate gas produces different phase regions such as gas phase, gas-liquid phase, gas-solid phase, gas-liquid-solid phase, etc. Above the dew point pressure, the WAT is less impacted from pressure while the WAT gradually decreases due to the dissolution effect below the dew point pressure. The experimental results are used to revise the software simulation results and then to obtain the phases of different temperature and pressure regions. The state envelope is used to predict the liquid separation and wax production situation at different production stages; the liquid condensation and waxing area of the Bozi 104 well lies in the surface pipeline behind the nozzle, where appropriate wax prevention measures are needed.

scholarly journals Performance Evaluation of CO2 Huff-n-Puff Gas Injection in Shale Gas Condensate Reservoirs

Energies ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 42 ◽  
Author(s):  
Xingbang Meng ◽  
Zhan Meng ◽  
Jixiang Ma ◽  
Tengfei Wang
Keyword(s):  
Oil Recovery ◽  
Shale Gas ◽  
Injection Pressure ◽  
Gas Condensate ◽  
Dew Point ◽  
Gas Condensate Reservoirs ◽  
Gas Recovery ◽  
Point Pressure ◽  
Shale Reservoirs ◽  
Dew Point Pressure

When the reservoir pressure is decreased lower than the dew point pressure in shale gas condensate reservoirs, condensate would be formed in the formation. Condensate accumulation severely reduces the commercial production of shale gas condensate reservoirs. Seeking ways to mitigate condensate in the formation and enhance both condensate and gas recovery in shale reservoirs has important significance. Very few related studies have been done. In this paper, both experimental and numerical studies were conducted to evaluate the performance of CO2 huff-n-puff to enhance the condensate recovery in shale reservoirs. Experimentally, CO2 huff-n-puff tests on shale core were conducted. A theoretical field scale simulation model was constructed. The effects of injection pressure, injection time, and soaking time on the efficiency of CO2 huff-n-puff were examined. Experimental results indicate that condensate recovery was enhanced to 30.36% after 5 cycles of CO2 huff-n-puff. In addition, simulation results indicate that the injection period and injection pressure should be optimized to ensure that the pressure of the main condensate region remains higher than the dew point pressure. The soaking process should be determined based on the injection pressure. This work may shed light on a better understanding of the CO2 huff-n-puff- enhanced oil recovery (EOR) strategy in shale gas condensate reservoirs.

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

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