Asphaltenes: What Do We Know So Far

2017 ◽  
Author(s):  
Abdulaziz S. Al-Qasim ◽  
Mohammed Alasker
Keyword(s):  
Crude Oil ◽  
Oil Production ◽  
Theoretical Models ◽  
Research Field ◽  
Light Transmittance ◽  
Asphaltene Precipitation ◽  
Bubble Point ◽  
Asphaltene Content ◽  
Point Pressure

Serious operational problems caused by asphaltene deposition during oil production have driven the ongoing effort to understand this phenomenon. Many studies have focused on related asphaltene precipitation flocculation and deposition in oil reservoirs and flow assurance in the wellbores. Experimental techniques and theoretical models have been developed trying to understand and predict asphaltene behavior. Nevertheless, some ambiguities still remain with regard to the characterization of asphaltene in crude oil and its stability during the primary, secondary, and tertiary recovery stages within the near-wellbore regions. The paper will review asphaltene in crude oil systems: asphaltene properties and their impact on oil production, including the effects of pressure, temperature, and composition. Asphaltene content is an important factor in determining the properties of a crude oil. Three main methods are used to measure the asphaltene content in laboratory: the first method called SARA, which separates dead oil into saturates, aromatics, resins, and asphaltenes depending on their solubility and polarity. The second is aliphatic hydrocarbon titration using dead oil; in this method the asphaltene precipitation point is detected by the asphaltene precipitation detection unit (APDU). The third method is the depressurization of a live oil bottomhole sample, this method depends on monitoring the flocculation point due to light transmittance caused by the infrared laser [3]. Solubility and density parameters trends are proportional to the pressure depletion until the pressure reaches the bubble point. Below the bubble point pressure (Pb), the solubility and density are inversely proportional to the pressure. The solubility increases linearly with temperature until the reservoir temperature, after that, it decreases linearly as the temperature increases. These advanced measurements facilitate an understanding of petroleum heavy constituents. Anew research field called “Petroleomics” has started receiving more attention; it is based on integrating the different knowledge of chemical composition of petroleum to develop correlation studies and improve the prediction of asphaltene phase behavior.

Determination of the Asphaltene Precipitation Envelope and Bubble Point Pressure for a Mexican Crude Oil by Scanning Transitiometry

2013 ◽  
Vol 27 (3) ◽  
pp. 1212-1222 ◽  
Author(s):  
Marco A. Aquino-Olivos ◽  
Jean-Pierre E. Grolier ◽  
Stanislaw L. Randzio ◽  
Adriana J. Aguirre-Gutiérrez ◽  
Fernando García-Sánchez
Keyword(s):  
Crude Oil ◽  
Asphaltene Precipitation ◽  
Bubble Point ◽  
Bubble Point Pressure ◽  
Point Pressure ◽  
Scanning Transitiometry

scholarly journals Multiphase flow modeling of asphaltene precipitation and deposition

2018 ◽  
Vol 73 ◽  
pp. 51 ◽  
Author(s):  
Amir Tabzar ◽  
Mohammad Fathinasab ◽  
Afshin Salehi ◽  
Babak Bahrami ◽  
Amir H. Mohammadi
Keyword(s):  
Multiphase Flow ◽  
Crude Oil ◽  
Flow Rate ◽  
Asphaltene Precipitation ◽  
Bubble Point ◽  
Bubble Point Pressure ◽  
Reservoir Fluid ◽  
Point Pressure ◽  
Component C ◽  
Onset Pressure

Asphaltene precipitation in reservoirs during production and Enhanced Oil Recovery (EOR) can cause serious problems that lead to reduction of reservoir fluid production. In order to study asphaltene tendency to precipitate and change in flow rate as a function of distance from wellbore, an equation of state (Peng-Robinson) based model namely Nghiem et al.’s model has been employed in this study. The heaviest components of crude oil are separated into two parts: The first portion is considered as non-precipitating component (C31A+) and the second one is considered as precipitating component (C31B+) and the precipitated asphaltene is considered as pure solid. For determination of the acentric factor and critical properties, Lee-Kesler and Twu correlations are employed, respectively. In this study, a multiphase flow (oil, gas and asphaltene) model for an asphaltenic crude oil for which asphaltene is considered as solid particles (precipitated, flocculated and deposited particles), has been developed. Furthermore, effect of asphaltene precipitation on porosity and permeability reduction has been studied. Results of this study indicate that asphaltene tendency to precipitate increases and permeability of porous medium decreases by increasing oil flow rate in under-saturated oil reservoirs and dropping reservoir pressure under bubble point pressure. On the other hand, asphaltene tendency to precipitate decreases with pressure reduction to a level lower than bubble point pressure where asphaltene starts to dissolve back into oil phase. Moreover, it is observed that precipitation zone around the wellbore develops with time as pressure declines to bubble point pressure (production rate increases up). Also, there is an equilibrium area near wellbore region at which reservoir fluid properties such as UAOP (Upper Asphaltene Onset Pressure) and LAOP (Lower Asphaltene Onset Pressure) are constant and independent of the distance from wellbore.

scholarly journals A Study of Asphaltene Precipitation Problem in some wells in Kurdistan Region

2020 ◽  
Vol 4 (6) ◽  
pp. 27-36
Author(s):  
akram Humoodi ◽  
Baroz Aziz ◽  
Dana Khidhir
Keyword(s):  
Crude Oil ◽  
Phase Behavior ◽  
Oil And Gas ◽  
Surface Condition ◽  
Oil And Gas Industry ◽  
Kurdistan Region ◽  
Asphaltene Precipitation ◽  
Oil Composition ◽  
Reservoir Conditions ◽  
Point Pressure

Throughout the production and reservoir lifecycle, the asphaltene precipitation is an ever existing problem through changing the porosity, permeability and wettability leading to decline in production. The conditions that govern Asphaltene precipitation varies from well to well and from reservoir conditions of high pressure and temperature to surface conditions and need to be studied case by case. The modeling and predicting the phase behavior and precipitation of Asphaltene is paramount for wells in Kurdistan region as it is developing its oil and gas industry. Crude oil samples from three wells in Kurdistan Region-Iraq were selected for this study. Experimental data such as crude oil composition using Gas Chromatography, PVT analysis and reservoir pressure and temperature were used as input data into Computer Modeling Group CMG simulator and a model of Asphaltene phase behavior was suggested. The model suggests that the maximum precipitation occurs near the bubble point pressure at reservoir conditions. This is validated and compared with results in literature indicating similar behavior of crude oil. To predict the Asphaltene precipitation at surface condition a modified Colloidal Instability Index CII were used and the results were validated by De Bore plot

Committee Machine-Ensemble as a General Paradigm for Accurate Prediction of Bubble Point Pressure of Crude Oil

2020 ◽  
Vol 143 (2) ◽  
Author(s):  
Sina Rashidi ◽  
Mohammad Khajehesfandeari
Keyword(s):  
Crude Oil ◽  
Phase Region ◽  
Accurate Prediction ◽  
Oil Reservoirs ◽  
Accurate Estimation ◽  
Two Phase ◽  
Committee Machine ◽  
Bubble Point ◽  
Bubble Point Pressure ◽  
Point Pressure

Abstract Bubble point pressure (BPP) not only is a basic pressure–volume–temperature (PVT) parameter for calculation nearly all of the crude oil characteristics, but also determines phase-type of oil reservoirs, gas-to-oil ratio, oil formation volume factor, inflow performance relationship, and so on. Since the measurement of BPP of crude oil is an expensive and time-consuming experiment, this study develops a committee machine-ensemble (CME) paradigm for accurate estimation of this parameter from solution gas-oil ratio, reservoir temperature, gas specific gravity, and stock-tank oil gravity. Our CME approach is designed using a linear combination of predictions of four different expert systems. Unknown coefficients of this combination are adjusted through minimizing deviation between actual BPPs and their associated predictions using differential evolution and genetic algorithm. Our proposed CME paradigm is developed using 380 PVT datasets for crude oils from different geological regions. This novel intelligent paradigm estimates available experimental databank with excellent accuracy i.e., absolute average relative deviation (AARD) of 6.06% and regression coefficient (R2) of 0.98777. Accurate prediction of BPP using our CME paradigm decreases the risk of producing from a two-phase region of oil reservoirs.

scholarly journals A Study of Asphaltene Precipitation Problem in some wells in Kurdistan Region

2020 ◽  
Vol 4 (6) ◽  
pp. 27-36
Author(s):  
akram Humoodi Abdulwahab ◽  
Baroz Aziz ◽  
Dana Khidhir
Keyword(s):  
Crude Oil ◽  
Phase Behavior ◽  
Oil And Gas ◽  
Surface Condition ◽  
Oil And Gas Industry ◽  
Kurdistan Region ◽  
Asphaltene Precipitation ◽  
Oil Composition ◽  
Reservoir Conditions ◽  
Point Pressure

Throughout the production and reservoir lifecycle, the asphaltene precipitation is an ever existing problem through changing the porosity, permeability and wettability leading to decline in production. The conditions that govern Asphaltene precipitation varies from well to well and from reservoir conditions of high pressure and temperature to surface conditions and need to be studied case by case. The modeling and predicting the phase behavior and precipitation of Asphaltene is paramount for wells in Kurdistan region as it is developing its oil and gas industry. Crude oil samples from three wells in Kurdistan Region-Iraq were selected for this study. Experimental data such as crude oil composition using Gas Chromatography, PVT analysis and reservoir pressure and temperature were used as input data into Computer Modeling Group CMG simulator and a model of Asphaltene phase behavior was suggested. The model suggests that the maximum precipitation occurs near the bubble point pressure at reservoir conditions. This is validated and compared with results in literature indicating similar behavior of crude oil. To predict the Asphaltene precipitation at surface condition a modified Colloidal Instability Index CII were used and the results were validated by De Bore plot

scholarly journals NEW DERIVED CORRELATIONS FOR LIBYAN CRUDE OIL TO ESTIMATE BUBBLE-POINT PRESSURE

2019 ◽  
Vol 2 (1) ◽  
pp. 1-13
Author(s):  
Mustafa Sharrad ◽  
Hamid Hakim Abd-Alrahman
Keyword(s):  
Crude Oil ◽  
Oil Recovery ◽  
Production Performance ◽  
Petroleum Engineering ◽  
Empirical Correlations ◽  
Bubble Point ◽  
Bubble Point Pressure ◽  
New Correlation ◽  
Future Production ◽  
Point Pressure

The key factor of all petroleum engineering calculation is the knowledge of the PVT (Pressure, Volume, Temperature) parameters, such as determination of oil and gas flowing properties, predicting production performance in the future, production facilities designing and enhanced oil recovery planning methods. Those PVT properties are ideally determined experimentally in the laboratory. However, some of these experimental data is not always available; consequently, empirical correlations are used to estimate them. Many researchers have been focusing on models for predicting reservoir fluid properties from the available experimental PVT data, such as reservoir pressure, temperature, crude oil API gravity, gas oil ratio, formation volume factor, and gas gravity. The present study compares between some of the available empirical PVT correlations for estimating the bubble point pressure of some Libyan crude oils based on 35 data point samples from different Libyan oil fields. In the second part of this study, a new correlation has been derived to predict the bubble point pressure using Eviews software and compares the output results of this new correlation with some derived correlations found in the literature using statistical analysis such as the Average Absolute Error (AARE). The results showed an AARE as low as 8.7%, for bubble point pressure estimated by this new derived correlation. These results are valid to compare to other driven empirical correlations that have been evaluated. 

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