Descriptive statistical analysis of experimental data for wettability alteration with surfactants in carbonate reservoirs

Fuel ◽  
2022 ◽  
Vol 310 ◽  
pp. 122110
Author(s):  
Ya Yao ◽  
Mingzhen Wei ◽  
Baojun Bai
Keyword(s):  
Experimental Data ◽  
Statistical Analysis ◽  
Carbonate Reservoirs ◽  
Wettability Alteration ◽  
Descriptive Statistical Analysis

scholarly journals Application of descriptive statistics in analysis of experimental data

2008 ◽  
Vol 62 (1-2) ◽  
pp. 85-95
Author(s):  
Milorad Mirilovic ◽  
Ivana Pejin
Keyword(s):  
Experimental Data ◽  
Statistical Analysis ◽  
Standard Deviation ◽  
Arithmetic Mean ◽  
Descriptive Statistics ◽  
Qualitative Investigation ◽  
Scientific Methods ◽  
The Subject ◽  
Variation Interval ◽  
Descriptive Statistical Analysis

Statistics today represent a group of scientific methods for the quantitative and qualitative investigation of variations in mass appearances. In fact, statistics present a group of methods that are used for the accumulation, analysis, presentation and interpretation of data necessary for reaching certain conclusions. Statistical analysis is divided into descriptive statistical analysis and inferential statistics. The values which represent the results of an experiment, and which are the subject of observation of a certain occurrence, are called parameters and they are divided into descriptive and numerical. All numerical parameters are divided into non-continuous and continuous. The graphic presentation of the distribution of frequencies can be by poligon or histogram. The most frequently applied descriptive statistical methods are: arithmetic mean, standard deviation, standard error of arithmetic mean, variation coefficient, and variation interval.

A Mechanistic Model for Wettability Alteration by Chemically Tuned Waterflooding in Carbonate Reservoirs

SPE Journal ◽  
2015 ◽  
Vol 20 (04) ◽  
pp. 767-783 ◽  
Author(s):  
C.. Qiao ◽  
L.. Li ◽  
R.T.. T. Johns ◽  
J.. Xu
Keyword(s):  
Experimental Data ◽  
Oil Recovery ◽  
Carbonate Rocks ◽  
Reactive Transport ◽  
Mechanistic Model ◽  
Contact Angles ◽  
Carbonate Reservoirs ◽  
Wettability Alteration ◽  
Physical Parameters ◽  
Minor Effect

Summary Injection of chemically tuned brines into carbonate reservoirs has been reported to enhance oil recovery by 5–30% original oil in place (OOIP) in coreflooding experiments and field tests. One proposed mechanism for this improved oil recovery (IOR) is wettability alteration of rock from oil-wet or mixed-wet to more-water-wet conditions. Modeling of wettability-alteration experiments, however, is challenging because of the complex interactions among ions in the brine and crude oil on the solid surface. In this research, we developed a multiphase and multicomponent reactive transport model that explicitly takes into account wettability alteration from these geochemical interactions in carbonate reservoirs. Published experimental data suggest that desorption of acidic-oil components from rock surfaces make carbonate rocks more water-wet. One widely accepted mechanism is that sulfate (SO42−) replaces the adsorbed carboxylic group from the rock surface, whereas cations (Ca2+, Mg2+) decrease the oil-surface potential. In the proposed mechanistic model, we used a reaction network that captures the competitive surface reactions among carboxylic groups, cations, and sulfate. These reactions control the wetting fractions and contact angles, which subsequently determine the capillary pressure, relative permeabilities, and residual oil saturations. The developed model was first tuned with experimental data from the Stevns Klint chalk and then used to predict oil recovery for additional untuned experiments under a variety of conditions where IOR increased by as much as 30% OOIP, depending on salinity and oil acidity. The numerical results showed that an increase in sulfate concentration can lead to an IOR of more than 40% OOIP, whereas cations such as Ca2+ have a relatively minor effect on recovery (approximately 5% OOIP). Physical parameters, including the total surface area of the rock and the diffusion coefficients, control the rate of recovery, but not the final oil recovery. The simulation results further demonstrate that the optimum brine formulations for chalk are those with relatively abundant SO42− (0.096 mol/kg water), moderate concentrations of cations, and low salinity (total ionic strength of less than 0.2 mol/kg water). These findings are consistent with the experimental data reported in the literature. The new model provides a powerful tool to predict the IOR potential of chemically tuned waterflooding in carbonate reservoirs under different scenarios. To the best of our knowledge, this is the first model that explicitly and mechanistically couples multiphase flow and multicomponent surface complexation with wettability alteration and oil recovery for carbonate rocks specifically.

ANALISIS PENGARUH MOTIVASI DAN KEDISIPLINAN TERHADAP PRESTASI KERJA PEGAWAI MELALUI PERILAKU KERJA PADA DKIPS PROVINSI SULAWESI BARAT

2020 ◽  
Vol 2 (1) ◽  
pp. 5-8
Author(s):  
Arnas A.M Patonangi ◽  
Cahyono Cahyono ◽  
Muhlis Ruslan
Keyword(s):  
Statistical Analysis ◽  
Work Performance ◽  
Work Motivation ◽  
Employee Performance ◽  
Partial Least Square ◽  
Least Square ◽  
Work Behavior ◽  
Test Results ◽  
Analysis Technique ◽  
Descriptive Statistical Analysis

Penelitian ini bertujuan untuk mengetahui apakah motivasi, kedisiplinan berpengaruh terhadap perilaku kerja, apakah motivasi dan kedisiplinan berpengaruh terhadap prestasi kerja, apakah perilaku kerja berpengaruh terhadap prestasi kerja, apakah motivasi berpengaruh terhadap prestasi kerja pegawai melalui perilaku kerja, serta apakah kedisiplinan berpengaruh terhadap prestasi kerja pegawai melalui perilaku kerja pada DKIPS Provinsi Sulawesi Barat. Teknik pengumpulan data melalui observasi, interview dan dokumentasi serta kuesioner. Sedangkan teknik analisis data yang digunakan adalah analisis statistic deskriptif, statistik infe-rensial, PLS (Partial Least Square), pengujian hipotesis. Hasil penelitian menemukan bahwa motivasi kerja berpengaruh positif dan signifikan terhadap perilaku kerja, Kedisiplinan berpengaruh positif dan signifikan terhadap perilaku kerja, Motivasi kerja berpengaruh positif dan signifikan terhadap prestasi kerja, Kedisiplinan berpengaruh positif dan signifikan terhadap prestasi kerja pegawai, Perilaku kerja berpengaruh positif dan signifikan terhadap prestasi kerja pegawai, hasil uji mediasi menunjukkan bahwa perilaku kerja dapat memediasi motivasi kerja terhadap prestasi kerja pegawai pada DKIPS Provinsi Sulawesi Barat, serta hasil uji mediasi menunjukkan bahwa perilaku kerja dapat memediasi disiplin kerja terhadap prestasi kerja pegawai pada DKIPS Provinsi Sulawesi Barat. This study aims to determine whether motivation, discipline affect work behavior, do motivation and discipline affect work performance, does work behavior affect work performance, does motivation affect employee performance through work behavior, and does discipline affect work performance through work behavior in West Sulawesi Province DKIPS. Data collection techniques through observation, interviews and documentation and questionnaires. While the data analysis technique used is descriptive statistical analysis, inferential statistics, PLS (Partial Least Square), hypothesis testing. The results found that work motivation has a positive and significant effect on work behavior, the discipline has a positive and significant effect on work behavior, work motivation has a positive and significant effect on work performance, the discipline has a positive and significant effect on employee work performance, work behavior has a positive and significant effect on employee work performance, mediation test results indicate that work behavior can mediate work motivation on employee work performance in DKIPS Province of West Sulawesi, and mediation test results indicate that work behavior can mediate work discipline towards employee work performance at DKIPS Province of West Sulawesi.

A New Dynamic Wettability-Alteration Model for Oil-Wet Cores During Surfactant-Solution Imbibition

SPE Journal ◽  
2013 ◽  
Vol 18 (05) ◽  
pp. 818-828 ◽  
Author(s):  
M. Hosein Kalaei ◽  
Don W. Green ◽  
G. Paul Willhite
Keyword(s):  
Experimental Data ◽  
Oil Recovery ◽  
History Matching ◽  
Mechanistic Model ◽  
Surfactant Solution ◽  
Experimental Tests ◽  
Quantitative Agreement ◽  
Wettability Alteration ◽  
Porous Rock ◽  
Surfactant Solutions

Summary Wettability modification of solid rocks with surfactants is an important process and has the potential to recover oil from reservoirs. When wettability is altered by use of surfactant solutions, capillary pressure, relative permeabilities, and residual oil saturations change wherever the porous rock is contacted by the surfactant. In this study, a mechanistic model is described in which wettability alteration is simulated by a new empirical correlation of the contact angle with surfactant concentration developed from experimental data. This model was tested against results from experimental tests in which oil was displaced from oil-wet cores by imbibition of surfactant solutions. Quantitative agreement between the simulation results of oil displacement and experimental data from the literature was obtained. Simulation of the imbibition of surfactant solution in laboratory-scale cores with the new model demonstrated that wettability alteration is a dynamic process, which plays a significant role in history matching and prediction of oil recovery from oil-wet porous media. In these simulations, the gravity force was the primary cause of the surfactant-solution invasion of the core that changed the rock wettability toward a less oil-wet state.

A Novel Coreflood Test to Evaluate EOR Potential of Wettability-Altering Surfactants in Oil-Wet Heterogeneous Carbonate Reservoirs

2021 ◽  
Author(s):  
Yue Shi ◽  
Kishore Mohanty ◽  
Manmath Panda
Keyword(s):  
Oil Recovery ◽  
Carbonate Reservoirs ◽  
Wettability Alteration ◽  
Low Permeability ◽  
High Permeability ◽  
Matrix Permeability ◽  
Rock Heterogeneity ◽  
The Matrix ◽  
Flow Through ◽  
Main Factors

Abstract Oil-wetness and heterogeneity (i.e., existence of low and high permeability regions) are two main factors that result in low oil recovery by waterflood in carbonate reservoirs. The injected water is likely to flow through high permeability regions and bypass the oil in low permeability matrix. In this study, systematic coreflood tests were carried out in both "homogeneous" cores and "heterogeneous" cores. The heterogeneous coreflood test was proposed to model the heterogeneity of carbonate reservoirs, bypassing in low-permeability matrix during waterfloods, and dynamic imbibition of surfactant into the low-permeability matrix. The results of homogeneous coreflood tests showed that both secondary-waterflood and secondary-surfactant flood can achieve high oil recovery (>50%) from relatively homogenous cores. A shut-in phase after the surfactant injection resulted in an additional oil recovery, which suggests enough time should be allowed while using surfactants for wettability alteration. The core with a higher extent of heterogeneity produced lower oil recovery to waterflood in the coreflood tests. Final oil recovery from the matrix depends on matrix permeability as well as the rock heterogeneity. The results of heterogeneous coreflood tests showed that a slow surfactant injection (dynamic imbibition) can significantly improve the oil recovery if the oil-wet reservoir is not well-swept.

scholarly journals The Ecuadorian Amazon: A Data Analysis of Social and Educational Characteristics of the Population

2017 ◽  
Vol 9 (1) ◽  
pp. 120 ◽  
Author(s):  
Gina Valdivieso ◽  
Efstathios Stefos ◽  
Ruth Lalama
Keyword(s):  
Data Analysis ◽  
Statistical Analysis ◽  
Marital Status ◽  
National Survey ◽  
Factorial Analysis ◽  
Place Of Birth ◽  
The Social ◽  
Ecuadorian Amazon ◽  
Level Of Instruction ◽  
Descriptive Statistical Analysis

The present study describes the social and educational characteristics of the Ecuadorian Amazon population. For this purpose, the data obtained from the National Survey of Employment, Unemployment and Underemployment of 2014 was used in this research. A descriptive statistical analysis presents the frequency, the percentages and the graphs of the variables related to the area in which people live, gender, age, ethnic self-identification, language spoken, marital status and level of instruction. Other variables are the use of computer and internet, place of birth, reason why they live in the Amazon region, type of activity or inactivity, how do they feel in their jobs, and groups of occupation. Also, a factorial analysis was used to show the main and most important criteria of differentiation and the the clusters of people with similar characteristics.

scholarly journals Orthogonal contrasts: definitions and concepts

2004 ◽  
Vol 61 (1) ◽  
pp. 118-124 ◽  
Author(s):  
Maria Cristina Stolf Nogueira
Keyword(s):  
Experimental Data ◽  
Statistical Analysis ◽  
Interaction Effects ◽  
Degree Of Freedom ◽  
Extensive Review ◽  
Single Degree Of Freedom ◽  
Orthogonal Contrasts ◽  
Single Degree ◽  
Definite Structure

The single degree of freedom of orthogonal contrasts is a useful technique for the analysis of experimental data and helpful in obtaining estimates of main, nested and interaction effects, for mean comparisons between groups of data and in obtaining specific residuals. Furthermore, the application of orthogonal contrasts is an alternative way of doing statistical analysis on data from non-conventional experiments, whithout a definite structure. To justify its application, an extensive review is made on the definitions and concepts involving contrasts.

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