Effect of Contact Time and Gas Component on Interfacial Tension of CO₂/Crude Oil System by Pendant Drop Method

Abstract

Pendant drop method has been used to measure the equilibrium interfacial tension and dynamic interfacial tension of CO2/crude oil system under the simulated-formation condition, in which the temperature is 355.65 K and pressure ranges from 0 MPa to 30 MPa. The test results indicated that the equilibrium interfacial tension of CO2/crude oil systems decreased with the increase of the systematic pressure. The dynamic interfacial tension of CO2/original oil, CO2/remaining oil, and CO2/produced oil systems is large at the initial contact and decreases gradually after that, and then finally it reaches dynamic balance. In addition, the higher the pressure is, the larger the magnitude of changing of CO2/crude oil interfacial tension with time will reduce. Moreover, by PVT phase experiment, gas-oil ratio, gas composition, and well fluid composition have been got, and different contents of light components in three oil samples under reservoir conditions have also been calculated. The relationship between equilibrium interfacial tensions and pressures of three different components of crude oil and CO2system was studied, and the higher C1is, the lower C2–C10will be, and the equilibrium interfacial tension will get higher. Therefore, the effect of light weight fractions on interfacial tension under formation conditions was studied.

Application and Research Progress of CO2 Stimulation Technology in Unconventional Oil and Gas Reservoirs: A Review and Prospect

“…Meanwhile, the properties of the two phases will become more and more similar when CO 2 is absorbed. This reduces the interfacial tension between the two. ,, Eventually, the two are mixed to form a miscible phase when their interfacial tension is equal to zero, as shown in Figure . ,, In addition, CO 2 is easier to enter pores when their interfacial tension is reduced, thereby improving recovery …”

Refractive Index Effects in Pendant Drop Tensiometry

“…The IFTs obtained with the calibration parameters in air was further corrected according to Eq. (11). Figure 6 shows a comparison among the IFTs between decane and water under the same experimental conditions but different calibration conditions.…”

“…The pendant drop method is one of the most widely used techniques for determining surface tension and interfacial tension (IFT) [1][2][3][4][5]. It has the advantages of great accuracy and flexibility and is capable of measuring both static and dynamic IFTs over a wide range of values under either ambient conditions or high temperature, high pressure conditions [6][7][8][9][10][11]. Axisymmetric drop shape analysis (ADSA) is a powerful method for determining IFT based on the drop or bubble shape.…”

Minimum Miscibility Pressure by the Vanishing Interfacial Tension Method: Effect of Pressure and Composition by Injection of Gas Cap into Dead/Live Oil

“…The declining rate of oil recycling charts in the primary and secondary stages has led reservoir engineers to embark on a variety of techniques to reduce residual oil saturation before abandonment of oil reservoirs. − About two-thirds of the original oil in place remains in the reservoirs at the end of the primary and secondary recovery. , Gas injection has been widely used for enhanced oil recovery (EOR) by injecting various types of gases (e.g., natural gas, enriched natural gas, carbon dioxide, nitrogen, or flue gas) into oil reservoirs to help increase oil recovery as a tertiary recovery stage. − …”