Improved Water Saturation Estimation Using Equivalent Rock Element Model and Application to Different Rock Types

Abstract

simple physical model that reflects the two main components in a pore structure and accounts for the first order transfer effect. This ensures compliance with physical boundary conditions and increases the predictiveness.(2) The innovative inclusion of critical water saturation avoids the underestimation of water saturation at low water saturations. It links electrical measurements with capillary pressure measurements and allows the two observations to cross-validate and complement each other. (3) The proposed method is demonstrated to match core measurements from different rock and pore types with a single model. P p Pf PfEquivalent Rock Element Model in 2D view

On the Concept and Challenges of Water Saturation Determination and Modeling in Carbonate Reservoirs

“…As the Sw is reduced going above the capillary transition zone, the data in the abovementioned plot tends to be a bit skewed to the right hand side of the default straight line Archie's saturation exponent parameter [10]. The fact has been shown in Figure 4 for a carbonate field.…”

Producing Light Oil from a Frozen Reservoir: Reservoir and Fluid Characterization of Umiat Field, National Petroleum Reserve, Alaska

“…Use of the Archie equation entails having adequate resistivity logs and Sw-log-derived data. In most cases, even the Archie's law may not comply with physical bounds and may create significant bias in the computed hydrocarbon saturation (Shang et al, 2008). Plotting the Resistivity Index (RI) (measured from SCAL) vs. the water saturation results in a line with the slope of n, the saturation exponent.…”

An improved saturation evaluation method of Chang 8 tight sandstone reservoir in Longdong West area of Ordos Basin, China

“…With further understanding of the conductive mechanism of tight sandstone reservoir, the saturation model based on the characteristics of rock pore structure has gradually become an important research area for logging interpretation and evaluation of low porosity and low permeability reservoir (Shanley and Cluff, 2015;Zhang et al, 2017Zhang et al, , 2018. Shang et al (2008) proposed the equivalent rock component saturation model by dividing the rock pore throat into parallel connection and series connection pores, which effectively reduced the influence of additional conductivity of reservoir on saturation. Li et al (2012) constructed the dual porosity component saturation model based on the pore structure characteristics, which has been well applied in the evaluation of low porosity and low permeability reservoirs in two Eastern oilfields of China.…”