A New Look at the Minimum Miscibility Pressure (MMP) Determination from Slimtube Measurements

Abstract

Slimtube measurement is one of the standard experimental techniques used for determining the minimum miscibility pressure (MMP) of an oil and injection gas system prior to the initiation of an enhanced oil recovery (EOR) project. It is preferred because it involves actual fluid displacement in a porous medium. However, the specific criterion for determining the cut-off point during the measurement is not uniquely agreed upon in the literature. Different criteria have been proposed by researchers and this has been one of the setbacks of using Slimtube measurements. The most commonly used criterion is the 1.2 PV criterion, which uses the recovery after injecting 1.2 pore volumes of the displacing gas as the cut-off. However, experimental observations show that even at supercritical condition, the volume of a gas is a strong function of the experimental pressure. Therefore, there is a need to develop an alternative means of determining the MMP that is not subject to particular pore volumes injected during Slimtube measurements. This work presents different means of determining the MMP, based entirely on recovery and the particular displacement phenomenon. In this approach, two new parameters are defined - the instantaneous recovery rate (IRR) and the oil recovery rate (ORR). The maximum values for these parameters for each experiment are used as the cut-off value. This new criteria was used in analyzing nine experimental data using oil from the Permian Basin. The results were compared with MMP prediction based on maximum recovery from each of the runs and the results were found to be in agreement. These new criteria will provide consistent cut-off point for experimental runs because Slimtube measurements take a long time to complete. The new procedure ensures that adequate data have been gathered during each experimental run, sufficient for a consistent experimental analysis.

Determination of the minimum miscibility pressure using the eclipse 300 simulator and compare it with the laboratory results

“…But the main problem with using this type of simulator is the severe effect of grading on the results, which results in a minimum miscibility pressure of the calculated value greater than the real value. 3 In all the miscible displacement processes, the moving fluid and the displacing fluid are mixed, that is, between the different miscible fluids; there is a dispersion phenomenon. 4 The dispersion creates a transient region in which the moving fluid dilutes the displacing fluid and affects the fuzzy behavior.…”

An Improved CO2-Crude Oil Minimum Miscibility Pressure Correlation

“…The minimum miscibility pressure (MMP) at which the crude oil and CO 2 become miscible is a key factor because, in general, the CO 2 is not miscible at first contact with reservoir oils but may achieve dynamic miscibility through multiple contact [2]. At present, prediction of the MMP commonly contains three methods: experiment [3], empirical correlation [4], and equation of state [5,6]. The slim tube test is one of the most commonly used test methods [3]; in addition, there are risingbubble apparatus (RBA) method [7], steam density method [8], multiple contact method [9], and interfacial tension vanish method [10].…”

“…At present, prediction of the MMP commonly contains three methods: experiment [3], empirical correlation [4], and equation of state [5,6]. The slim tube test is one of the most commonly used test methods [3]; in addition, there are risingbubble apparatus (RBA) method [7], steam density method [8], multiple contact method [9], and interfacial tension vanish method [10]. The experimental method is the standard method, but it needs to consume large amounts of time and money.…”

Improved Method for Calculating Minimum Miscibility Pressure for Gas Flooding

“…The MMP can be found experimentally [3][4][5][6][7] and by calculation using empirical equations [8][9][10][11] and the equation of state [12,13]. The primary experimental method for estimating the MMP is the slim-tube test [3].…”

“…The primary experimental method for estimating the MMP is the slim-tube test [3]. The indicated method is standard, but it is expensive and takes considerable time.…”