Effect of Temperature Level upon Capillary Pressure Curves

Abstract

A number of recent studies of drainage relative permeability ratio by dynamic displacement have permeability ratio by dynamic displacement have indicated temperature sensitivity. Poston et al. found that the irreducible water saturation appeared to increase significantly with temperature-level increase and speculated that capillary pressure saturation data would also change to show this effect. Although there have been capillary pressure-saturation studies which show important pressure-saturation studies which show important differences between laboratory and reservoir conditions (presumably higher temperatures), the effects have usually been attributed to adsorption and desorption of polar components from the liquid phases. There appears to be no systematic studies phases. There appears to be no systematic studies of the effect of temperature level upon capillary pressure. pressure. Equipment was constructed to permit measuring capillary pressures for simple systems at temperatures ranging from room temperature to about 350 deg. F. Drainage and imbibition capillary pressure curves were measured for three consolidated pressure curves were measured for three consolidated sandstones and one limestone sample, at either three or four temperature levels form 70 deg to 325 deg F. Fluid used were a filtered white oil and distilled water. Results for the sandstone samples were similar. The practical irreducible water saturation increased significantly as temperature was raised from 70 deg F to the maximum temperature studies - about 325 deg F. Surprisingly, the hysteresis between drainage and imbibition cycles decreased as temperature increased and was nearly absent at 300 deg F. Results indicated that the sandstone samples became markedly more water-wet as temperature level increased. Results for the limestone sample were quite different. All capillary pressure-saturation curves for the various isotherms were found to lie within the envelope of the room-temperature drainage and imbibition curves. The main objective of this study was to determine whether the supposition of Poston et al. was correct. Results are in agreement with the previous dynamic displacement work. Introduction In 1967, Poston et al reported displacement experiments on unconsolidated sands at elevated temperatures and found that the irreducible water saturation increased with temperature increase. The oil viscosity appeared to have had no real effect on their results. Although less conclusive, practical residual oil saturations (to a producing practical residual oil saturations (to a producing water-oil ratio of 100) appeared to decrease with temperature increase. The results also indicated important increases in both oil and water relative permeabilities as temperature increased. This led permeabilities as temperature increased. This led Poston et al. to suggest that temperature affects. Poston et al. to suggest that temperature affects. the sand wettability. Sessile-drop contact angle measurements indicated that the water-oil-glass contact angle decreased with temperature increase. The results of Poston et al. regarding an increase in irreducible water saturation with temperature increase and the nondependence of this finding on the viscosity ratio deserve more attention. it is a well established concept in the literature that increasing water wetness of sands is reflected in an increase in the irreducible water saturation and an increase in oil recovery efficiency. The effect on a capillary pressure-saturation curve would be to cause a shift toward increasing irreducible wetting-phase saturation. if this is the case, then the studies of McNiel and Moss and Willman et al. should give partial credit for the added oil recovery efficiency involved in hot water flooding to the effect of temperature level upon wettability. In view of the potential importance of hot fluid injection for improving oil recovery and the lack of an adequate description of the flow process and thermodynamics involved, it was decided to study the speculation of Poston et al. that capillary pressure-saturation curves should be temperature pressure-saturation curves should be temperature dependent. This study concerns the effect of temperature level upon capillary pressure-saturation relationships for consolidated porous media. SPEJ p. 13

Dynamic effects on capillary pressure–Saturation relationships for two‐phase porous flow: Implications of temperature

“…She and Sleep 33 studied the temperature dependence of capillary pressure-saturation relationships for water-perchloroethylene (PCE) and water-air systems in silica sand with temperatures ranging from 20 to 80 C. They reported that for water-PCE system the irreducible water saturation increases and the residual nonwetting saturation decreases as the temperature increases. This result was quite similar to the results of Sinnokrot et al 27 and Davis 29 even though they used different fluid pair (water-CHEVRON 15 white oil) and different sand domain (consolidated natural sandstone). In terms of the capillary pressure, She and Sleep 33 concluded that it decreases when the temperature increases.…”

“…However, some authors report the effects of temperatures on the two-phase porous flow behavior. 5,[27][28][29][30][31][32][33][34][35][36][37][38][39][40] Sinnokrot et al 27 determined the effects of temperature on capillary pressure curves through measurement of drainage and imbibition capillary pressures for three consolidated sandstones and one limestone core. Lo and Mungan 41 proposed that oil recovery operations are more efficient at higher temperature.…”

Effect of Temperature on Athabasca Type Heavy Oil – Water Relative Permeability Curves in Glass Bead Packs

“…There are some reports showing that the value of oil relative permeability (k ro ) increases while the value of water relative permeability (k rw ) decreases at higher temperatures. The effect of temperature on the end point saturations (S wi and S or ) has been reported by several authors (Edmondson, 1965;Combarnous & Pavan, 1968;Poston et al, 1970;Sinnokrot, 1971;Lo & Mungan, 1973;Weinbrandt et al, 1975;Abasov et al, 1976;Maini & Batycky, 1985;Torabzadeh & Handy, 1984;Bennion et al, 1985). All these authors except Combarnous and Pavan (1968) have also reported the change of k r curves with temperature.…”

Thermal variation of organic fluid properties and impact on thermal remediation feasibility

“…If the net effect of these changes is to increase the ratio |i/(Y cos 8), residual blobs of NAPL may be displaced at lower flushing velocities than would be required at ambient aquifer temperatures. Poston et al (1970), Sinnokrot et al (1971), and Hjelmeland and Larrondo (1986) have shown experimentally that organic-water contact angles decrease as temperature is raised, with oil-wet reservoirs sometimes becoming water wet. Decreases in contact angles lead to increases in cos 0, and further decreases in the capillary number.…”