Rock-physics-based carbonate pore type characterization and reservoir permeability heterogeneity evaluation, Upper San Andres reservoir, Permian Basin, west Texas

Experimental Study of Water and CO2 Flooding in the Tight Main Pay Zone and Vuggy Residual Oil Zone of a Carbonate Reservoir

“…23 The detailed experimental setup and procedure were described in the previous work. 17 The measured equilibrium IFTs between the Steelman light crude oil and CO 2 at 17 different equilibrium pressures of P eq = 1.08−18.66 MPa and T res = 51.1°C are 0.40 C 29 0.65 C 4 1.59 C 30 0.57 C 5 3.94 C 31 0.57 C 6 8.26 C 32 0.53 C 7 12.27 C 33 0.37 C 8 8.19 C 34 0.34 C 9 7.66 C 35 0.41 C 10 6.52 C 36 0.31 C 11 6.04 C 37 0.30 C 12 4.58 C 38 0.21 C 13 4.41 C 39 0.27 C 14 3.92 C 40 0.27 C 15 3.65 C 41 0.13 C 16 2.95 C 42 0.12 C 17 2.55 C 43 0.17 C 18 2.43 C 44 0.17 C 19 2.12 C 45 0.10 C 20 1.66 C 46 0.10 C 21 1.84 C 47 0.09 C 22 1.02 C 48 0.08 C 23 1.31 C 49 0.08 C 24 1.12 C 50+ 1.34 C 25 1.07 total 100.00 C 26 0.96 24 On the basis of the measured data in Figure 2, the equilibrium IFT γ eq (mJ/m 2 ) is correlated to the equilibrium pressure P eq (MPa) by applying the linear regression in the above-mentioned two equilibrium pressure ranges, respectively. …”

“…6,7 However, the permeability of a highly heterogeneous carbonate reservoir can have a large variation of more than 4 orders of magnitude as a result of the complicated porosity types, rock textures, and mineral compositions. 8 In general, these complicated lithological characteristics result in a low oil recovery factor (RF) in the carbonate oil reservoir.…”

Computational modeling of calcite cementation in saline limestone aquifers: a phase-field study

“…Carbonate reservoirs are known to be ubiquitously heterogeneous in nature (Westphal 2004;Dou 2011). In the pore spaces of carbonate sediments, there is a wide variety of substrates such as crystalline limestone fragments and carbonate fossils, among others, upon which the nucleation of cement can take place.…”

Investigation of pore-type heterogeneity and its inherent genetic mechanisms in deeply buried carbonate reservoirs based on some analytical methods of rock physics

“…For a given fluid phase, these inclusions and their pore structures have a stronger effect on seismic velocity than porosity Eberli, 1993, 1999;Dou et al, 2011;Sun, 2004;Sun et al, 2006;Xu et al, 2007). A practical and repeatable rock physics model is required to discern different pore types and characterize the relationship between the seismic velocity and petrophysical properties of carbonates.…”

“…Numerous improvements have been made to overcome these limitations based on the use of acoustic and density logs (Schlumberger, 1974;Meese and Walther, 1967;Brie et al, 1985;Lucia and Conti, 1987;Anselmetti and Eberli, 1999). Sun's model extended the Biot theory and defined a key effective pore structure parameter called the frame flexibility factor (g), which can be used to quantify the variation of pore structure on core and log scales and invert carbonate reservoir permeability from seismic data (Dou et al, 2011;Gartner et al, 2005;Sun, 2000Sun, , 2004. Verwer et al (2011) and Weger et al (2009) introduced a digital image analysis method to quantitatively describe pore-space geometry and detail its effect on sonic velocity, resistivity and permeability.…”