Effect of Liquid Invasion and Capillary Pressure on Wireline Formation Tester Measurements in Tight Gas Reservoirs

2012 ◽  
Author(s):  
Joshua Thomas Andrews ◽  
Hassan Bahrami ◽  
Reza Rezaee ◽  
Sultan Mehmood ◽  
Hossein Majid Salemi
Keyword(s):  
Capillary Pressure ◽  
Tight Gas ◽  
Gas Reservoirs ◽  
Tight Gas Reservoirs

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.

Effect of liquid invasion damage and supercharging on wireline formation tester measurements in tight gas reservoirs

2012 ◽  
Vol 52 (1) ◽  
pp. 627 ◽  
Author(s):  
Joshua Andrews ◽  
Hassan Bahrami ◽  
Reza Rezaee ◽  
Hamid Reza ◽  
Sultan Mehmood ◽  
...  
Keyword(s):  
Capillary Pressure ◽  
Drilling Fluid ◽  
Gas Production ◽  
Tight Gas ◽  
Formation Pressure ◽  
Gas Reservoirs ◽  
Reliable Determination ◽  
Tight Gas Reservoirs ◽  
Tight Gas Reservoir ◽  
Measured Pressure

Wireline formation testing and measurement of true formation pressure can provide essential knowledge about the reservoir dynamic characteristics. In tight formations, a reliable determination of pressure and mobility gradients is challenging because of the tight nature of formation rock. Due to the very low reservoir permeability, the mud cake across wellbore is often ineffective in preventing filtrate invasion, thus causing the measured pressure to be higher than actual formation pressure as a result of supercharging effect. Wireline formation testing measurements are also influenced by the effects of filtrate invasion and capillary pressure, as the measured pressure is pressure of drilling fluid filtrate, the continuous phase present in the invaded region around wellbore. As a result, the measured pressure might be different to true formation pressure. This effect is more noticeable in tight gas reservoirs due to capillary pressure effect. This paper looks into estimation of true formation pressure and evaluates the effect of filtrate invasion damage and supercharging on wireline formation tester measurements in tight gas reservoirs. Numerical simulation approach is used to build the reservoir model based on data acquired from a tight gas reservoir. The model undergoes water injection followed by gas production from different testing points along the wellbore, and the corresponding pressure gradients are plotted to check for pressure matching with that of the formation fluid in the virgin region. The results indicate the significant effects of supercharging, reservoir characteristics, capillary pressure and liquid invasion damage on wireline formation pressure measurements in tight gas reservoirs.

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

A new dynamic capillary-number-recovery evaluation method for tight gas reservoirs

2021 ◽  
pp. 108730
Author(s):  
Fulei Zhao ◽  
Pengcheng Liu ◽  
Shengye Hao ◽  
Xinyu Qiu ◽  
Ce Shan ◽  
...  
Keyword(s):  
Capillary Number ◽  
Evaluation Method ◽  
Tight Gas ◽  
Gas Reservoirs ◽  
Tight Gas Reservoirs
Sign in / Sign up

Export Citation Format

Share Document