Vp-Vs ratio sensitivity to pressure, fluid, and lithology changes in tight gas sandstones
نویسندگان
چکیده
Low Vp/Vs anomalies can assist in prospect identification in tight gas sandstone reservoirs, because they are related to good quality rocks (sandstones with low clay content), presence of gas, and overpressure conditions. In such rocks, gas saturation lowers Vp/Vs and the effect is larger if the gas is overpressured. On the other hand, with water saturation, Vp/Vs increases and the effect is enhanced with decreasing differential pressure. Furthermore, tight gas sandstones typically have a Vp/Vs lower than that in shales.
منابع مشابه
Gaseous Reservoir Horizons Determination via Vp/Vs and Q-Factor Data, Kangan-Dalan Formations, in One of SW Iranian hydrocarbon Fields
An important method in oil and gas exploration is vertical seismic profile (VSP) to estimate rock properties in drilling well. Quality factor is also the crucial point of seismic attenuate in VSP data. In the present study, this factor was used to evaluate the hydrocarbon potential of Kangan Formation in one of the Persian Gulf oil fields using VSP zero offset method. Quality factor was estimat...
متن کاملAn interpretative approach for gas zone identification and lithology discrimination using derivatives of λ∗ρ and μ∗ρ attributes
The “λ”term, or incompressibility, is sensitive to pore fluid, whereas the “μ” term, or rigidity, is sensitive to the rock matrix as described in the original paper by Goodway et al(1997) that gives the physical interpretation of the lambda λ and mu (μ) attributes. As per the theory, it is impossible to de-couple the effects of density from” λ” and “μ“when extracting this information from sei...
متن کاملPseudo Steady State Gas Flow in Tight Reservoir under Dual Mechanism Flow
Gas reservoirs with low permeability (k<0.1 mD) are among the unconventional reservoirs and are commonly termed as "Tight Gas Reservoirs". In conventional gas reservoirs that have high permeability, the flow of gas is basically controlled by the reservoir permeability and it is calculated using the Darcy equation. In these reservoirs, gas flow due to gas diffusion is ignored compared to Dar...
متن کاملOurnal of Pplied Cience and Nvironmental Anagement
The cross plotting of rock properties for fluid and lithology discrimination was carried out in a Niger Delta oil field using well data from a given oil field. The data used for the analysis consist of suites of six wells. The reservoir was evaluated using gamma ray logs, volume of shale, resistivity and neutron porosity for well-02 and well-06. Sand lithology showed low gamma ray, high resisti...
متن کاملToward a Thorough Approach to Predicting Klinkenberg Permeability in a Tight Gas Reservoir: A Comparative Study
Klinkenberg permeability is an important parameter in tight gas reservoirs. There are conventional methods for determining it, but these methods depend on core permeability. Cores are few in number, but well logs are usually accessible for all wells and provide continuous information. In this regard, regression methods have been used to achieve reliable relations between log readings and Klinke...
متن کامل