A New Technique For Reservoir Wettability Characterization

Thermal-recovery methods (e.g., steam injection) are commonly used to recover bitumen from oil sands. The injected steam contacts the oil sand and forms an interface. The steam changes to water, transferring its heat to bitumen across this interface. The heated bitumen will have a lower viscosity, which allows for oil to be mobilized and recovered from the reservoir.Studies that explain hot-water/bitumen interfaces are crucial for understanding thermal-recovery methods. The strength and energy of hot-water/bitumen interfaces are expected to play important roles in the recovery of bitumen from oil sands. However, measurements on hot-water/bitumen interfaces are scarce in the literature. A relevant measurement would be the contact angle and interfacial tension (IFT) of the water/bitumen interfaces at different temperatures. In this paper, it has been attempted to reveal and present the results of several water/bitumen contact-angle and IFT measurements. The measurements cover a temperature range from ambient to 100 o C for a given pressure.The experiments are run in X-ray transparent cells, and images are taken using a microcomputed-tomography (microCT) scanner. The results of contact angle and the IFTs of the hot-water/bitumen interface are produced by using the axisymmetric drop shape-analysis (ADSA) method.

show abstract

“…Details can be found in the works of Vijapurapu and Rao (2004), Vijapurapu et al (2002), Rao (1999Rao ( , 1996, and Rao and Girard (1996).…”

Section: Introductionmentioning

confidence: 99%

Effect of Temperature and Pressure on Contact Angle and Interfacial Tension of Quartz/Water/Bitumen Systems

Rajayi

Kantzas

2011

Journal of Canadian Petroleum Technology

View full text Add to dashboard Cite

show abstract

“…Hence, it is doubtful whether the true definition of the water-advancing angle is satisfied in these techniques. To overcome the disadvantages of these conventional techniques, the DDDC technique has been developed for reliable and reproducible contact-angle measurements (Rao and Girard 1996;Rao 1999). This technique satisfies the fundamental definition of the water-advancing contact angle and requires relatively short test durations of 2 to 3 days.…”

Section: Contact Angles Measurement Techniquesmentioning

confidence: 99%

“…Two types of surfactants, one nonionic (ethoxy alcohol) and the other anionic (ethoxy sulfate), were used to investigate the surfactant-induced interfacial interactions in the Yates reservoir-rock/ fluids system at reservoir conditions. Two experimental techniques, the DDDC technique (Rao and Girard 1996;Rao 2002) for contact-angle measurements and the DSA technique for IFT measurements, have been chosen for measurement of surfactant-induced interfacial interactions at reservoir conditions. Both these techniques can be used at high pressures and high temperatures and yield reliable and reproducible measurements.…”

Section: Experimental Reagents Apparatus and Proceduresmentioning

confidence: 99%

“…In this technique, both oil drops on the two crystal surfaces are aged as sessile drops with buoyancy forces acting upwards, producing an oilcontacted area on the rock surface. By turning the lower crystal upside down and mingling the two oil drops, the advancing and receding contact angles can be measured by shifting the lower crystal laterally, which also helps in monitoring of the solid/oil/ water three-phases contact line (TPCL) movements within the areas previously exposed to crude oil (Rao and Girard 1996;Rao 2002). The measurement is reproducible by moving the oil drop back to the original position.…”

Section: Experimental Reagents Apparatus and Proceduresmentioning

confidence: 99%

See 1 more Smart Citation

Measurement of Surfactant-Induced Interfacial Interactions at Reservoir Conditions

Ayirala

Rao

2008

SPE Reservoir Evaluation &Amp; Engineering

View full text Add to dashboard Cite

The effect of surface-active chemicals on oil/water interfacial tension (IFT) and wettability in crude-oil/brine/rock systems at reservoir conditions is important in enhanced-oil-recovery (EOR) processes. However, most of the experimental studies on IFT and contact angles have been conducted at ambient conditions and using stock-tank crude oils. In this study, live and stock-tank crude oils have been used at reservoir conditions to make IFT and dynamic contact-angle measurements using the drop-shape-analysis (DSA) and dual-drop/dual-crystal (DD/DC) techniques, respectively. Yates reservoir rock and fluids, and two types of surfactants (nonionic and anionic) in varying concentrations have been used at reservoir conditions of 82°F and 700 psi (27.8°C and 4.8 MPa).The dynamic oil/water IFT was found to be a strong function of oil composition and of temperature, and it showed a slight dependence on pressure. An attempt has been made to explain the dynamic behavior of IFT using a four-stage mechanistic model involving induction, diffusion, kinetic-barrier, and equilibrium stages. The significant difference observed between the advancing contact angles of live oil (55°) and stock-tank oil (154°) clearly indicates the need to use live oils at reservoir conditions to determine in-situ reservoir wettability. Anionic surfactant altered the weakly water-wet behavior of live oil to strongly oil-wet (165°). It was also able to alter the strong oil-wet behavior of stock-tank oil to less oil-wet (<135°). The nonionic surfactant was able to alter the water-wet live oil system to intermediate-wet (82°), while it did not affect the strongly oil-wet behavior of stock tank oil system.The oil-wet behavior observed for live oil with surfactants indicates the capability of these surfactants to develop continuous oil-wet paths for potential mixed-wettability development. Thus, this study is of practical significance in cases where the surfactantinduced wettability alterations to either intermediate-wet or mixedwet can result in improved oil recovery through the lowering of both capillary and adhesion forces.

show abstract

“…Values of in-situ contact angles and local capillary pressure are not distinguishable [9]. In a different approach, static and dynamic contact angles have been vastly measured on a flat surface representing a specific mineral surface (i.e., silica, mica, or natural rock) using various methods such as sessile drop, captive bubble, Wilhelmy plate, and dual-drop dual-crystal (DDDC) methods [18][19][20][21][22][23][24][25][26][27][28][29]. High discrepancies in contact angles measured in literature have been observed.…”

Section: Introductionmentioning

confidence: 99%

Direct Measurement of Static and Dynamic Contact Angles Using a Random Micromodel Considering Geological CO2 Sequestration

Jafari

Jung

2017

Sustainability

View full text Add to dashboard Cite

Abstract:The pore-level two-phase fluids flow mechanism needs to be understood for geological CO 2 sequestration as a solution to mitigate anthropogenic emission of carbon dioxide. Capillary pressure at the interface of water-CO 2 influences CO 2 injectability, capacity, and safety of the storage system. Wettability usually measured by contact angle is always a major uncertainty source among important parameters affecting capillary pressure. The contact angle is mostly determined on a flat surface as a representative of the rock surface. However, a simple and precise method for determining in situ contact angle at pore-scale is needed to simulate fluids flow in porous media. Recent progresses in X-ray tomography technique has provided a robust way to measure in situ contact angle of rocks. However, slow imaging and complicated image processing make it impossible to measure dynamic contact angle. In the present paper, a series of static and dynamic contact angles as well as contact angles on flat surface were measured inside a micromodel with random pattern of channels under high pressure condition. Our results showed a wide range of pore-scale contact angles, implying complexity of the pore-scale contact angle even in a highly smooth and chemically homogenous glass micromodel. Receding contact angle (RCA) showed more reproducibility compared to advancing contact angle (ACA) and static contact angle (SCA) for repeating tests and during both drainage and imbibition. With decreasing pore size, RCA was increased. The hysteresis of the dynamic contact angle (ACA-RCA) was higher at pressure of one megapascal in comparison with that at eight megapascals. The CO 2 bubble had higher mobility at higher depths due to lower hysteresis which is unfavorable. CO 2 bubbles resting on the flat surface of the micromodel channel showed a wide range of contact angles. They were much higher than reported contact angle values observed with sessile drop or captive bubble tests on a flat plate of glass in previous reports. This implies that more precaution is required when estimating capillary pressure and leakage risk.

show abstract

A New Technique For Reservoir Wettability Characterization

Cited by 19 publications

References 0 publications

Effect of Temperature and Pressure on Contact Angle and Interfacial Tension of Quartz/Water/Bitumen Systems

Effect of Temperature and Pressure on Contact Angle and Interfacial Tension of Quartz/Water/Bitumen Systems

Measurement of Surfactant-Induced Interfacial Interactions at Reservoir Conditions

Direct Measurement of Static and Dynamic Contact Angles Using a Random Micromodel Considering Geological CO2 Sequestration

Contact Info

Product

Resources

About