Improving Well Productivity of Tight Gas Reservoirs by Using Sodium Silicate in Water-Based Drill-in Fluid

2018 ◽  
Author(s):  
T. Jafarov ◽  
M. Mahmoud ◽  
A. Al-Majed ◽  
S. Elkatatny ◽  
B. Bageri
Keyword(s):  
Sodium Silicate ◽  
Tight Gas ◽  
Gas Reservoirs ◽  
Well Productivity ◽  
Tight Gas Reservoirs ◽  
Water Based

Lowering the phase-trap damage in tight-gas reservoirs by using interfacial tension (IFT) reducers

2013 ◽  
Vol 53 (1) ◽  
pp. 363
Author(s):  
Yangfan Lu ◽  
Hassan Bahrami ◽  
Mofazzal Hossain ◽  
Ahmad Jamili ◽  
Arshad Ahmed ◽  
...  
Keyword(s):  
Relative Permeability ◽  
Reservoir Simulation ◽  
Water Saturation ◽  
Tight Gas ◽  
Gas Reservoirs ◽  
Tight Gas Reservoirs ◽  
Water Based ◽  
Tight Formations ◽  
Tight Reservoirs ◽  
Relative Permeability Curves

Tight-gas reservoirs have low permeability and significant damage. When drilling the tight formations, wellbore liquid invades the formation and increases water saturation of the near wellbore area and significantly deceases permeability of this area. Because of the invasion, the permeability of the invasion zone near the wellbore in tight-gas formations significantly decreases. This damage is mainly controlled by wettability and capillary pressure (Pc). One of the methods to improve productivity of tight-gas reservoirs is to reduce IFT between formation gas and invaded water to remove phase trapping. The invasion of wellbore liquid into tight formations can damage permeability controlled by Pc and relative permeability curves. In the case of drilling by using a water-based mud, tight formations are sensitive to the invasion damage due to the high-critical water saturation and capillary pressures. Reducing the Pc is an effective way to increase the well productivity. Using the IFT reducers, Pc effect is reduced and trapped phase can be recovered; therefore, productivity of the TGS reservoirs can be increased significantly. This study focuses on reducing phase-trapping damage in tight reservoirs by using reservoir simulation to examine the methods, such use of IFT reducers in water-based-drilled tight formations that can reduce Pc effect. The Pc and relative permeability curves are corrected based on the reduced IFT; they are then input to the reservoir simulation model to quantitatively understand how IFT reducers can help improve productivity of tight reservoirs.

Liquid loading in wellbores and its effect on cleanup period and well productivity in tight gas sand reservoirs

2010 ◽  
Vol 50 (1) ◽  
pp. 559
Author(s):  
Hassan Bahrami ◽  
M Reza Rezaee ◽  
Vamegh Rasouli ◽  
Armin Hosseinian
Keyword(s):  
Numerical Simulation ◽  
Gas Production ◽  
Production Performance ◽  
Tight Gas ◽  
Gas Reservoirs ◽  
Liquid Loading ◽  
Performance Modelling ◽  
Well Productivity ◽  
Tight Gas Reservoirs ◽  
Tight Gas Reservoir

Tight gas reservoirs normally have production problems due to very low matrix permeability and significant damage during well drilling, completion, stimulation and production. Therefore they might not flow gas to surface at optimum rates without advanced production improvement techniques. After well stimulation and fracturing operations, invaded liquids such as filtrate will flow from the reservoir into the wellbore, as gas is produced during well cleanup. In addition, there might be production of condensate with gas. The produced liquids when loaded and re-circulated downhole in wellbores, can significantly reduce the gas production rate and well productivity in tight gas formations. This paper presents assessments of tight gas reservoir productivity issues related to liquid loading in wellbores using numerical simulation of multiphase flow in deviated and horizontal wells. A field example of production logging in a horizontal well is used to verify reliability of the numerical simulation model outputs. Well production performance modelling is also performed to quantitatively evaluate water loading in a typical tight gas well, and test the water unloading techniques that can improve the well productivity. The results indicate the effect of downhole liquid loading on well productivity in tight gas reservoirs. It also shows how well cleanup is sped up with the improved well productivity when downhole circulating liquids are lifted using the proposed methods.

Using relative permeability curves to evaluate phase trapping damage caused by water- and oil-based drilling fluids in tight-gas reservoirs

2012 ◽  
Vol 52 (1) ◽  
pp. 595 ◽  
Author(s):  
Geeno Murickan ◽  
Hassan Bahrami ◽  
Reza Rezaee ◽  
Ali Saeedi ◽  
Tsar Mitchel
Keyword(s):  
Capillary Pressure ◽  
Relative Permeability ◽  
Drilling Fluid ◽  
Tight Gas ◽  
Gas Reservoirs ◽  
Tight Gas Reservoirs ◽  
Water Based ◽  
Tight Formations ◽  
Relative Permeability Curves ◽  
Tight Formation

Low matrix permeability and significant damage mechanisms are the main signatures of tight-gas reservoirs. During the drilling and fracturing of tight formations, the wellbore liquid invades the tight formation, increases liquid saturation around the wellbore, and eventually reduces permeability at the near wellbore zone. The liquid invasion damage is mainly controlled by capillary pressure and relative permeability curves. Due to high critical water saturation, relative permeability effects and strong capillary pressure, tight formations are sensitive to water invasion damage, making water blocking and phase trapping damage two of the main concerns with using a water-based drilling fluid in tight-gas reservoirs.Therefore, the use of an oil-based mud may be preferred in the drilling or fracturing of a tight formation. Invasion of an oil filtrate into tight formations, however, may result in the introduction of an immiscible liquid-hydrocarbon drilling or completion fluid around the wellbore, causing the entrapment of an additional third phase in the porous media that would exacerbate formation damage effects. This study focuses on phase trapping damage caused by liquid invasion using a water-based drilling fluid in comparison with the use of an oil-based drilling fluid in water-sensitive, tight-gas sand reservoirs. Reservoir simulation approach is used to study the effect of relative permeability curves on phase trap damage, and the results of laboratory experiments of core flooding tests in a West Australian tight-gas reservoir are shown, where the effect of water injection and oil injection on the damage of core permeability are studied. The results highlight the benefits of using oil-based fluids in drilling and fracturing of tight-gas reservoirs in terms of reducing skin factor and improving well productivity.

Experimental Study on Reducing Water Phase Trapping in Tight Gas Reservoirs

2013 ◽  
Vol 295-298 ◽  
pp. 3293-3297
Author(s):  
Hao Zhang ◽  
Xiao Ning Feng ◽  
Ji Ping She ◽  
Fu You Huang ◽  
Guan Fang Li
Keyword(s):  
Water Saturation ◽  
Water Phase ◽  
Tight Gas ◽  
Prevention Measures ◽  
Gas Reservoirs ◽  
Reservoir Water ◽  
Tight Gas Reservoirs ◽  
Western Sichuan ◽  
Water Based ◽  
Western Sichuan Basin

This document explains and demonstrates how to reduce water phase trapping in tight gas reservoirs during drilling. The water phase trapping laboratory device and experiment method has been studied, through the experiments on reservoir water phase trapping of western Sichuan Basin in China, Knowing that the damage is very serious, water self absorption experiments with different periods show that porosity and permeability of cores are basically above 50%. for the reason, the high capillary pressure and low water saturation are the main factors. Water phase trapping damage prevention measures has been put forward, including avoiding using water-based operating fluid as much as possible, minimizing or even avoiding the invasion of water-based operating fluid, and reducing interfacial tension and promote smooth operating fluid flow back.

Evaluation of damage mechanisms and skin factor in tight gas reservoirs

2011 ◽  
Vol 51 (1) ◽  
pp. 639 ◽  
Author(s):  
Hassan Bahrami ◽  
Reza Rezaee ◽  
Delair Nazhat ◽  
Jakov Ostojic
Keyword(s):  
Significant Influence ◽  
Permeability Reduction ◽  
Tight Gas ◽  
Natural Fractures ◽  
Gas Reservoirs ◽  
Damage Mechanisms ◽  
Well Productivity ◽  
Tight Gas Reservoirs ◽  
Skin Factor ◽  
Water Blocking

Tight gas reservoirs normally have production problems due to very low matrix permeability and significant damage during well drilling, completion, stimulation and production. Therefore, they may not flow gas at optimum rates without advanced production improvement techniques. The main damage mechanisms and the factors that have significant influence on total skin factor in tight gas reservoirs include: mechanical damage to formation rock; plugging of natural fractures by mud solid particle invasion; relative permeability reduction around wellbore as a result of filtrate invasion; liquid leak-off into the formation during fracturing operations; water blocking; skin due to wellbore breakouts; and the damage associated with perforation. Drilling and fracturing fluids invasion mostly occurs through natural fractures and may also lead to serious permeability reduction in the rock matrix that surrounds the natural or hydraulic fractures. This study represents an evaluation of different damage mechanisms in tight gas formations, and examines the factors that can have significant influence on total skin factor and well productivity. Reservoir simulation was carried out based on a typical West Australian tight gas reservoir to understand how well productivity is affected by each of the damage mechanisms, such as natural fracture plugging, mud filtrate invasion, water blocking and perforation. Furthermore, some damage prevention and productivity improvement techniques are proposed, which can help improve well productivity in tight gas reservoirs.

scholarly journals Modified Horizontal Well Productivity Model for a Tight Gas Reservoir Subjected to Non-Uniform Damage and Turbulence

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8334
Author(s):  
Samuel O. Osisanya ◽  
Ajayi Temitope Ayokunle ◽  
Bisweswar Ghosh ◽  
Abhijith Suboyin
Keyword(s):  
Flow Rate ◽  
Horizontal Well ◽  
Horizontal Wells ◽  
Total Production ◽  
Tight Gas ◽  
Gas Reservoirs ◽  
Well Productivity ◽  
Tight Gas Reservoirs ◽  
Skin Factor ◽  
Tight Gas Reservoir

Tight gas reservoirs are finding greater interest with the advancement of technology and realistic prediction of flow rate and pressure from such wells are critical in project economics. This paper presents a modified productivity equation for tight gas horizontal wells by modifying the mechanical skin factor to account for non-uniform formation damage along with the incorporation of turbulence effect in the near-wellbore region. Hawkin’s formula for calculating skin factor considers the radius of damage as a constant value, which is less accurate in low-permeability tight gas reservoirs. This paper uses a multi-segment horizontal well approach to develop the local skin factors and the equivalent skin factor by equating the total production from the entire horizontal well to the sum of the flow from individual segmented damaged zones along the well length. Conical and horn-shaped damaged profiles are used to develop the equivalent skin used in the horizontal well productivity equation. The productivity model is applied to a case study involving the development of a tight gas field with horizontal wells. The influence of the horizontal well length, damaged zone permeability, drainage area, reservoir thickness, and wellbore diameter on the calculated equivalent skin (of a non-uniform skin distribution) and the flow rate (with turbulence and no turbulence) are investigated. The results obtained from this investigation show significant potential to assist in making practical decisions on the favorable parameters for the success of the field development in terms of equivalent skin factor, flow rate, and inflow performance relationships (IPR).

Data Acquistion and Formation Evaluation Strategies in Anistrospic, Tight Gas Reservoirs

2008 ◽  
Author(s):  
Hans de Koningh ◽  
Bernd Heinrich Herold ◽  
Koksal Cig ◽  
Fahd Ali ◽  
Sultan Mahruqy ◽  
...  
Keyword(s):  
Tight Gas ◽  
Gas Reservoirs ◽  
Tight Gas Reservoirs ◽  
Formation Evaluation ◽  
Evaluation Strategies ◽  
Data Acquistion
Sign in / Sign up

Export Citation Format

Share Document