Experimental and Numerical Investigations on the Effect of Unconventional Oil Wells Lateral’s Undulating Amplitude on Transient Multiphase Flow Behavior

Abstract

The increasing popularity of unconventional wells has sparked a heightened interest in evaluating and predicting their production performance. With the use of extended reach well structures, these wells are able to generate and access larger reservoir volumes. Hence, it is crucial to understand how the well's lateral trajectory affects its transient production performance. The assessment of lateral trajectory undulating amplitude effect on the flow behavior is performed in the current study based on the experimental results obtained at the University of North Dakota, Undulated Two-Phase (UTP) Flow Loop, injecting air and water mixture through a variable undulating amplitude section followed by a vertical section. The experiments showed that the undulating amplitude increase induced lower translational velocity, frequency, and length, with a consistent slug acceleration through the system profile from the inlet to the vertical section and a decreasing frequency when the slugs travel through the vertical section. Measured data shows that an increase of the horizontal pressure losses and variability is expected with a higher undulation amplitude, translating the fact that larger instabilities are observed for higher amplitudes. The numerical simulation predicted lower translational velocity and frequency, higher slug’s lengths, and similar vertical pressure losses when compared to the experimental results.

Investigating the Impact of Undulation Amplitude of Unconventional Oil Well Laterals on Transient Multiphase Flow Behavior: Experimental and Numerical Study

“…By adjusting the vertical position, undulation amplitudes of 0, 5, 10, and 20 cm can be obtained, which correspond to 0, 1, 2, and 4 times the diameter in terms of dimensionless undulation amplitude. The operation of the experimental facility utilizes the equipment specifications outlined in A photo of the flow-loop facility is shown in Figure 3 in a three-undulation configuration, with instrumentation connected and fluids being pumped into the test section [5]. The operation of the experimental facility utilizes the equipment specifications outlined in Table 1.…”

“…The operation of the experimental facility utilizes the equipment specifications outlined in Table 1. A photo of the flow-loop facility is shown in Figure 3 in a three-undulation configuration, with instrumentation connected and fluids being pumped into the test section [5].…”

“…It is important to note that, regarding uncertainty, the measurement uncertainty of the water holdup probes has been thoroughly assessed, as reported in [5]. The in-house water holdup probes showed a maximum uncertainty of 9.43%, while the remaining instruments had a maximum uncertainty of 3%, resulting in a total uncertainty of 12.43% in the worst case and extreme operating conditions.…”

“…Slugging is an undesired phenomenon creating flow instabilities, which can impair the performance of liquid-producing wells, as shown in [1,5,6], which also has implications for gas-well liquid-loading studies, as shown in [7][8][9][10][11][12][13][14], and CO 2 storage due to wellbore phase change, as shown in [15][16][17][18][19][20][21].…”

Study on open‐hole extended‐reach limit in horizontal drilling with wavy wellbore trajectory

“…Khetib et al 9 deduce that the complex wellbore trajectory may lead to severe slug during the gas lift through a tow‐phase flow experiment. Khetib 10 propose that the amplitude and frequency of undulation of the wavy trajectory also have complex effects on production during oil recovery.…”