Asphaltene Deposition During CO2 Flooding: A Laboratory Assessment

1997 ◽  
Author(s):  
Raj K. Srivastava ◽  
Sam S. Huang
Keyword(s):  
Co2 Flooding ◽  
Laboratory Assessment ◽  
Asphaltene Deposition

scholarly journals Asphaltene Deposition during CO2 Flooding in Ultralow Permeability Reservoirs: A Case Study from Changqing Oil Field

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Li Rong-tao ◽  
Liao Xin-wei ◽  
Zou Jian-dong ◽  
Gao Chang-wang ◽  
Zhao Dong-feng ◽  
...  
Keyword(s):  
Adverse Effects ◽  
Injection Rate ◽  
Oil Field ◽  
Formation Damage ◽  
Co2 Flooding ◽  
Asphaltene Precipitation ◽  
Asphaltene Content ◽  
Asphaltene Deposition ◽  
Ultralow Permeability

Asphaltene deposition is a common phenomenon during CO2 flooding in ultralow permeability reservoirs. The deposited asphaltene occupies the pore volume and decreases permeability, resulting in serious formation damage and pore well productivity. It is urgent to investigate the asphaltene deposition mechanisms, adverse effects, and preventive measures. However, few asphaltene deposition investigations have been systematically conducted by now. In this research, the asphaltene precipitation mechanisms and adverse effects were comprehensively investigated by using experimental and numerical methods. To study the effects of pressure, asphaltene content, and temperature on asphaltene precipitation qualitatively and quantitatively, the microscope visible detection experiment and the PVT cell static experiment were firstly conducted. The adverse effects on porosity and permeability resulted from asphaltene deposition were also studied by the core flooding experiment. Secondly, simulation models of asphaltene precipitation and deposition were developed and validated by experimental data. Finally, a case study from Changqing oil field was presented to analyze the asphaltene deposition characteristic and preventive measures. The experimental results showed that the asphaltene precipitation increases with the increased pressure before reaching the minimum miscible pressure (MMP) and gets the peak value around the MMP, while decreases slowly. The asphaltene precipitation increases with the increased temperature and asphaltene content. The variation trend of adverse effects on porosity and permeability resulted from asphaltene deposition is similar to that of asphaltene precipitation under the influence of pressure, asphaltene content, and temperature. The case study shows that the water-altering-gas (WAG) with high injection rate suffers more serious asphaltene deposition compared with the WAG with low injection rate, for the asphaltene precipitation increases as the increased pressure before reaching the MMP. The CO2 continuous injection with high injection rate is the worst choice, for low sweep efficiency and the most severe formation damage. Thus, the WAG with optimal injection rate was proposed to maintain well productivity and to reduce formation damage resulted from asphaltene deposition during developing ultralow permeability reservoirs.

Asphaltene Deposition During CO2 Flooding

1999 ◽  
Vol 14 (04) ◽  
pp. 235-245 ◽  
Author(s):  
R.K. Srivastava ◽  
S.S. Huang ◽  
Mingzhe Dong
Keyword(s):  
Co2 Flooding ◽  
Asphaltene Deposition

Sulfur and Asphaltene Deposition During CO2 Flooding of Carbonate Reservoirs

2009 ◽  
Author(s):  
Abdulrazag Yusef Zekri ◽  
Shedid A. Shedid ◽  
Reyadh A. Almehaideb
Keyword(s):  
Carbonate Reservoirs ◽  
Co2 Flooding ◽  
Asphaltene Deposition

Visualization of asphaltene deposition effects on porosity and permeability during CO2 flooding in porous media

2016 ◽  
Vol 19 (4) ◽  
pp. 603-614 ◽  
Author(s):  
Yuechao Zhao ◽  
Tonglei Wang ◽  
Yongchen Song ◽  
Yu Liu ◽  
Bo Dong ◽  
...  
Keyword(s):  
Porous Media ◽  
Co2 Flooding ◽  
Asphaltene Deposition ◽  
Porosity And Permeability

POSTOPERATIVE COMPLIANCE OF BARIATRIC SURGERY PATIENTS REGARDING THE ASSESSMENT OF SERUM LEPTIN LEVELS AND INSULIN RESISTANCE

2019 ◽  
Vol 49 (1/2019) ◽  
Keyword(s):  
Insulin Resistance ◽  
Bariatric Surgery ◽  
Serum Levels ◽  
Medical Laboratory ◽  
Leptin Resistance ◽  
Obese Patients ◽  
Laboratory Assessment ◽  
Serum Leptin ◽  
Before And After ◽  
Bariatric Patients

Background and aims: Overweight and obese patients who undergo bariatric surgery require a rigorous clinical and paraclinical assessment both before and after the surgery at 3, 6, and 12 months.The present study aims the assessment of serum leptin levels and insulin resistance status in compliant bariatric patients to scheduled medical laboratory assessment at 6 months after surgery. Material and Method: The study included 109 eligible patients selected for bariatric surgery, 48 of whom attended the scheduled visit at 6 months after the surgery. Laboratory assessing regarded the insulin resistance by determining before meal the serum levels of leptin, glucose and insulin, as well as HOMA 1 and HOMA 2 indexes. Results: Patients who underwent bariatric treatment experienced a significant decrease in insulin resistance status. A higher percentage in the preoperative group was recorded in women, feature which was also recorded in the postoperative group that attended the scheduled visit at 6 months after surgery. Age is also an important factor that significantly influences the behavioral adherence to postoperative visits. Conclusions: Insulin resistance status improved significantly in 6 months after bariatric surgery among the fully compliant patients. The percentage of attendance at scheduled visits is higher among women, and decreases with age. Keywords: obesity surgery, leptin resistance, insulin resistance, HOMA index, compliance

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