Calculating Asphaltenes Precipitation Onset Pressure by Using Cardanol as Precipitation Inhibitor: A Strategy to Increment the Oil Well Production

Abstract

Asphaltenes precipitation is considered a formation damage problem, which can reduce the oil recovery factor. It fouls piping and surface installations, as well as cause serious flow assurance complications and decline oil well production. Therefore, researchers have shown an interest in chemical treatments to control this phenomenon. The aim of this paper is to assess the asphaltenes precipitation onset of crude oils in the presence of cardanol, by titrating the crude with n-heptane. Moreover, based on this results obtained at atmosphere pressure, the asphaltenes precipitation onset pressure were calculated to predict asphaltenes precipitation in the reservoir, by using differential liberation and refractive index data of the oils. The influence of cardanol concentration on the asphaltenes stabilization of three Brazilian crude oils samples (with similar API densities) was studied. Therefore, three formulations of cardanol were prepared: The formulations were added to the crude at 5:98, 1.5:98.5, 2:98 and 4:96 ratios. The petroleum samples were characterized by API density, elemental analysis and differential liberation test. The asphaltenes precipitation onset was determined by titrating with n-heptane and monitoring with near-infrared (NIR). The asphaltenes precipitation onset pressures were estimated. The envelope phase of the crude oils were also determined by numerical simulation (pipesim). In addition, supported in the downhole well profile and a screening methodology, the adequate artificial lift systems (ALS) for the oils were selected. Finally, the oil flow rates were modelling by NODAL analysis production system in the SNAP software. The results of this study show the refractive index for each sample, and the predictive pressure to asphaltene instability. The asphaltenes precipitation onset of the crude oils were 2.06, 2.30 and 6.02 mL of n-heptane/g of oil. The cardanol was an effective inhibitor of asphaltenes precipitation, since it displaces the precipitation pressure of the oil to lower values. This indicates that cardanol can increase the oil wells productivity.

Comparative Analysis of CO2, N2, and Gas Mixture Injection on Asphaltene Deposition Pressure in Reservoir Conditions

“…The researchers investigated the effect on inhibiting the asphaltene deposition of cardanol. The results of this study showed that the asphaltene precipitation onsets (APO) of the crude oil were 2.06, 2.30, and 6.02 mL n-heptane/g of oil and cardanol was an effective inhibitor of asphaltene precipitation [26]. Ram et al investigated the effect of pressure-depletion-induced asphaltene precipitation on interfacial properties of live-oil, brine, and quartz systems as well as the hysteresis of the contact angle after aging in high pressure and high temperature (HPHT) conditions.…”

“…CO 2 0.00 C 17 2.55 N 2 1.78 C 18 2.36 C 1 27.45 C 19 2.08 C 2 1.04 C 20 1.77 C 3 0.18 C 21 1.67 iC 4 0.06 C 22 1.53 nC 4 0.04 C 23 1.42 iC 5 0.00 C 24 1.31 nC 5 0.00 C 25 1.38 C 6 0.00 C 26 1.52 C 7 0.15 C 27 1.78 C 8 0.24 C 28 1.94 C 9 0.83 C 29 1.86 C 10 0.45 C 30 1.62 C 11 0.88 C 31 1.15 C 12 1.42 C 32 0.90 C 13 1.97 C 33 0.72 C 14 2.35 C 34 0.61 C 15 2.17 C 35 0.56 C 16 2.33 C 36+ 27.93 The composition of crude oil with different CO 2 and N 2 injection volumes was simulated by inputting the composition of crude oil into the PVTsim Nova. The molar volume content change of the light hydrocarbon components (C 1 -C 4 ) and the heavy hydrocarbon components (C 36+ ) induced by CO 2 and N 2 injection are shown in Table 3.…”

Asphaltene Precipitation/Deposition Estimation and Inhibition through Nanotechnology: A Comprehensive Review

“…The pressure at which this occurs, at a given temperature, is named precipitation onset pressure. Knowing this value accurately provides more tools for reservoir and production engineers to make decisions to propose alternatives and solutions to overcome the problem related to the destabilization of asphaltenes [14].…”

“…Many works involving the determination of asphaltene precipitation at atmospheric pressure are available [15][16][17][18][19][20][21][22][23][24][25]. Some others investigate the behavior of asphaltenes at reservoir conditions [14,[26][27][28][29][30][31][32]. These inconveniences generate economic damage, as they can alter petrophysical properties causing severe damage to the reservoir; for example, the presence of asphaltenes in the solid form can lead to the blocking of pores in the production formation, a loss of effective porosity, changes in permeability, changes in wettability, and an increase in oil viscosity [3,[5][6][7].…”

“…Many works involving the determination of asphaltene precipitation at atmospheric pressure are available [15][16][17][18][19][20][21][22][23][24][25]. Some others investigate the behavior of asphaltenes at reservoir conditions [14,[26][27][28][29][30][31][32].…”