Formation Damage by CO2 Asphaltene Precipitation

2006 ◽  
Author(s):  
Roland Tenjoh Okwen
Keyword(s):  
Formation Damage ◽  
Asphaltene Precipitation

Formation Damage Through Asphaltene Precipitation Resulting From CO2 Gas Injection in Iranian Carbonate Reservoirs

2008 ◽  
Vol 23 (02) ◽  
pp. 210-214 ◽  
Author(s):  
AmirMasoud Kalantari-Dahaghi ◽  
Vida Gholami ◽  
Jamshid Moghadasi ◽  
R. Abdi
Keyword(s):  
Gas Injection ◽  
Carbonate Reservoirs ◽  
Formation Damage ◽  
Asphaltene Precipitation ◽  
Co2 Gas

Modeling Formation Damage by Asphaltene Deposition During Primary Oil Recovery

2005 ◽  
Vol 127 (4) ◽  
pp. 310-317 ◽  
Author(s):  
Shaojun Wang ◽  
Faruk Civan
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Oil Recovery ◽  
Oil Reservoirs ◽  
Formation Damage ◽  
Asphaltene Precipitation ◽  
Vertical Wells ◽  
Core Flow ◽  
Asphaltene Deposition

Asphaltene precipitation and deposition during primary oil recovery and resulting reservoir formation damage are described by a phenomenological mathematical model. This model is applied using experimental data from laboratory core flow tests. The effect of asphaltene deposition on porosity, permeability, and the productivity of vertical wells in asphaltenic-oil reservoirs are investigated by simulation.

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.

scholarly journals Oil production and reservoir damage during miscible CO2 injection

2020 ◽  
Vol 39 (1) ◽  
pp. 22-28 ◽  
Author(s):  
Qian Wang ◽  
Piroska Lorinczi ◽  
Paul W. J. Glover
Keyword(s):  
Oil Recovery ◽  
Oil Production ◽  
Control Measures ◽  
Co2 Injection ◽  
Formation Damage ◽  
Core Flooding ◽  
Asphaltene Precipitation ◽  
Pore Throat ◽  
Oil Distribution ◽  
Inorganic Precipitation

The blockage and alteration of wettability in reservoirs caused by asphaltene deposits are problems that contribute to poor oil recovery performance during carbon dioxide (CO2) injection. Oil production and reservoir damage are both controlled by macroscopic interlayer heterogeneity and microscopic pore-throat structure and may be optimized by the choice of flooding method. In this work, the residual oil distribution and the permeability decline caused by organic and inorganic precipitation after miscible CO2 flooding and water-alternating-CO2 (CO2-WAG) flooding have been studied by carrying out core-flooding experiments on a model heterogeneous three-layer reservoir. For CO2, flooding experimental results indicate that the low-permeability layers retain a large oil production potential even in the late stages of production, while the permeability decline due to formation damage is larger in the high-permeability layer. We found that CO2-WAG can reduce the influence of heterogeneity on the oil production, but it results in more serious reservoir damage, with permeability decline caused by CO2–brine–rock interactions becoming significant. In addition, miscible CO2 flooding has been carried out for rocks with similar permeabilities but different wettabilities and different pore-throat microstructures in order to study the effects of wettability and pore-throat microstructure on formation damage. Reservoir rocks with smaller pore-throat sizes and more heterogeneous pore-throat microstructures were found to be more sensitive to asphaltene precipitation, with corresponding lower oil recovery and greater decreases in permeability. However, it was found that the degree of water wetness for cores with larger, more connected pore-throat microstructures became weaker due to asphaltene precipitation to pore surfaces. Decreasing the degree of water wetness was found to be exacerbated by increases in the sweep volume of injected CO2 that arise from cores with larger and better connected pore throats. Erosion of water wetness is a disadvantage for enhanced oil recovery operations as asphaltene precipitation prevention and control measures become more necessary.

scholarly journals Cardanol /SiO2 Nanocomposites for Inhibition of Formation Damage by Asphaltene Precipitation/Deposition in Light Crude Oil Reservoirs. Part II: Nanocomposite Evaluation and Coreflooding Test

ACS Omega ◽  
2020 ◽  
Vol 5 (43) ◽  
pp. 27800-27810
Author(s):  
Daniel López ◽  
Juan E. Jaramillo ◽  
Elizabete F. Lucas ◽  
Masoud Riazi ◽  
Sergio H. Lopera ◽  
...  
Keyword(s):  
Crude Oil ◽  
Oil Reservoirs ◽  
Formation Damage ◽  
Asphaltene Precipitation ◽  
Light Crude Oil ◽  
Sio2 Nanocomposites

scholarly journals Formation damage due to asphaltene precipitation during CO2 flooding processes with NMR technique

2019 ◽  
Vol 74 ◽  
pp. 11 ◽  
Author(s):  
Kun Qian ◽  
Shenglai Yang ◽  
Hong-en Dou ◽  
Jieqiong Pang ◽  
Yu Huang
Keyword(s):  
Oil Recovery ◽  
Oil And Gas ◽  
Dominant Role ◽  
Injection Pressure ◽  
Recovery Process ◽  
Core Sample ◽  
Formation Damage ◽  
Co2 Flooding ◽  
Asphaltene Precipitation ◽  
The Core

In order to quantitatively evaluate the pore-scale formation damage of tight sandstones caused by asphaltene precipitation during CO2 flooding, the coreflood tests and Nuclear Magnetic Resonance (NMR) relaxometry measurements have been designed and applied. Five CO2 coreflood tests at immiscible, near-miscible and miscible conditions were conducted and the characteristics of the produced oil and gas were analyzed. For each coreflood test, the T2 spectrum of the core sample was measured and compared before and after CO2 flooding to determine the asphaltene precipitation distribution in pores. It is found that, the solubility and extraction effect of the CO2 plays a more dominant role in the CO2-EOR (Enhanced Oil Recovery) process with higher injection pressure. And, more light components are extracted and recovered by the CO2 and more heavy components including asphaltene are left in the core sample. Thus, the severity of formation damage influenced by asphaltene precipitation increases as the injection pressure increases. In comparison to micro and small pores (0.1–10 ms), the asphaltene precipitation has a greater influence on the medium and large pores (10–1000 ms) due to the sufficient interaction between the CO2 and crude oil in the medium and large pores. Furthermore, the asphaltene precipitation not only causes pore clogging, but also induces rock wettability to alter towards oil-wet direction.

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