An investigation of the effect of wettability on NMR characteristics of sandstone rock and fluid systems

NMR wettability indices: Effect of OBM on wettability and NMR responses

“…They found that water relaxed faster in the water-wet system than in the oil-wet system. Later works (Devereux, 1967;Saraf et al, 1970;Williams and Fung, 1982;Borgia et al, 1991;Hsu et al, 1992;Howard, 1994;Straley et al, 1995;Daughney et al, 2000;Zhang et al, 2000;Al-Mahrooqi et al, 2003;Manalo et al, 2003) confirm that NMR technique can give qualitative information about wettability. However, the quantitative connection between wettability and NMR characteristic parameter has been investigated by only a few studies (Howard, 1998;Guan et al, 2002;Fleury and Deflandre, 2003).…”

A rapid measurement of : The DECPMG sequence

“…Although some promising methods have been proposed recently to relate NMR relaxation parameters and wettability [43][44][45][46], mixed wettability surfaces are still difficult to characterise [47]. The T 1 =T 2 ratio can be used to estimate the average surface residency time of liquid molecules in a pore.…”

Determination of movable fluid percentage and movable fluid porosity in ultra-low permeability sandstone using nuclear magnetic resonance (NMR) technique

“…The NMR technique has been applied for formation evaluation purposes for several decades. The characteristics of fluid in the rock pores, effective porosity, permeability, movable and irreducible fluid volume, porous structure, and other geological information related to reservoir physical properties can be directly obtained by interpreting the NMR signals of hydrogen nucleus in fluid contained in the pores (Wang et al, 2001a;Weng et al, 2003;Al-Mahrooqi et al, 2003, 2006Tan and Zhao, 2006). Timur (1969) successfully applied the pulsed NMR to study the porosity, movable fluid, and permeability of sandstones.…”