Reservoir facies

Carvalho, M.V.F., De Ros, L.F. Gomes, N.S. (1995) Carbonate cementation patterns and diagenetic reservoir facies in the Campos Basin Cretaceous turbidites, oflFshoreeastern Brazil. Mar. Petrol. GeoU 12, 741-758. 

Sellwood, B.W., Sheperd, T.J., Evans M.R. James, B, (1989) Origin of late cements in oolitic reservoir facies a fluid inclusion and isotopic study (Mid-Jurassic, southern England). Sediment. Geol., 61, 223-231. 

In this case study, well data are used to calibrate seismic facies with the main reservoir facies (oil saturated sand, water saturated sand, sand injections, shales and shales streaks). The results of the 3D seismic facies classification are shown in Figure 13 along a horizon-based slice just above the bottom of the reservoir sands. 

It is sometimes advantageous to employ a burette with an extended jet which is bent twice at right angles so that the tip of the jet is displaced by some 7.5-10 cm from the body of the burette. Insertion of the tip of the burette into complicated assemblies of apparatus is thus faci itated, and there is a further advantage, that if heated solutions have to be titrated the body of the burette is kept away from the source of heat. Burettes fitted with two-way stopcocks are useful for attachment to reservoirs of stock solutions. 

Petroleum reservoirs, however, occur in a gray facies of the Lyons found in the deep basin (Levandowski et al., 1973). This facies contains no ferric oxides... 

Saner, S.Abdulaziz Al-Hasthi, Maung Than Htay, 1996, Use of tortuosity for discriminating electro-facies to interpret the electrical parameters of carbonate reservoir rocks. Journal ofPetro. Science Engineering, 16, pp. 237-249. 

Several attempts have been made to integrate geochemical parameters into this framework of system tracts to assist in differentiating one facies from another. Potential source rocks can be found in all three system tracts, with the richest source rocks generally found in the condensed section within a TST. The best petroleum reservoirs are found in LST. With the use of geochemical data, the various system tracts in a sequence can be identified and therefore used to distinguish the location of both potential petroleum source rocks and reservoirs. 

There is no clear evidence of major faults within the Sm0rbukk reservoir (Heum et al., 1986), and pressure barriers within the same formation appear not to be structurally controlled (Ehrenberg et al., 1992). It is therefore possible that compartmentalization to a large extent is due to progressive burial diagenesis of sandstones and siltstones, particularly in the Tilje Formation which may have lateral facies variations. 

Reservoir and Facies Division, Exxon Production Research Company, Houston,... 

Bruhn, C.H.L (1993) High-re..solution stratigraphy, reservoir geometry and facies characterization of Cretaceous and Tertiary turhidites from rift and passive margin Brazilian basins. PhD thesis, McMaster University, Hamilton. 

Core analysis data are displayed as continuous logs in Fig. 2. Porosity varies from > 0 to 19%. Permeability varies from <0.1 mD to > 5000 mD. Porosity and permeability are highest where the rocks are most coarse grained. However, again the correlation is not perfect the tops of the sandbodies tend to have low porosity and permeability values relative to the middle and lower portions of sandbodies (Fig. 2). Consequently, grain size and facies variations cannot be used in isolation to understand or predict variations in reservoir quality. 

Reservoir quality in the Chaunoy Formation is a function not just of depositional facies but also of localized cement distribution. Building a reservoir model using primary sandbody architecture alone is insufficient to correctly describe reservoir quality. 

Gibbons, K., Hellem, T., Kjemperud, A., Nio, S.D. Vebenstad, K. (1993) Sequence architecture, facies development and carbonate-cemented horizons in the Troll Field reservoir, offshore Norway. In Advances in Reservoir Geology (Ed. Ashton, M.). Spec. Publ. Geol. Soc. Lond., 69, 1-31. 

---