Formation damage due to asphaltene precipitation during CO2 flooding processes with NMR technique
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, ne...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
EDP Sciences
2019-01-01
|
| Series: | Oil & Gas Science and Technology |
| Online Access: | https://doi.org/10.2516/ogst/2018084 |
| _version_ | 1818414791234945024 |
|---|---|
| author | Qian Kun Yang Shenglai Dou Hong-en Pang Jieqiong Huang Yu |
| author_facet | Qian Kun Yang Shenglai Dou Hong-en Pang Jieqiong Huang Yu |
| author_sort | Qian Kun |
| collection | DOAJ |
| description | 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. |
| first_indexed | 2024-12-14T11:24:42Z |
| format | Article |
| id | doaj.art-1b1949793e4d4cc0814048e4068ee7c5 |
| institution | Directory Open Access Journal |
| issn | 1294-4475 1953-8189 |
| language | English |
| last_indexed | 2024-12-14T11:24:42Z |
| publishDate | 2019-01-01 |
| publisher | EDP Sciences |
| record_format | Article |
| series | Oil & Gas Science and Technology |
| spelling | doaj.art-1b1949793e4d4cc0814048e4068ee7c52022-12-21T23:03:35ZengEDP SciencesOil & Gas Science and Technology1294-44751953-81892019-01-01741110.2516/ogst/2018084ogst180231Formation damage due to asphaltene precipitation during CO2 flooding processes with NMR techniqueQian KunYang ShenglaiDou Hong-enPang JieqiongHuang YuIn 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.https://doi.org/10.2516/ogst/2018084 |
| spellingShingle | Qian Kun Yang Shenglai Dou Hong-en Pang Jieqiong Huang Yu Formation damage due to asphaltene precipitation during CO2 flooding processes with NMR technique Oil & Gas Science and Technology |
| title | Formation damage due to asphaltene precipitation during CO2 flooding processes with NMR technique |
| title_full | Formation damage due to asphaltene precipitation during CO2 flooding processes with NMR technique |
| title_fullStr | Formation damage due to asphaltene precipitation during CO2 flooding processes with NMR technique |
| title_full_unstemmed | Formation damage due to asphaltene precipitation during CO2 flooding processes with NMR technique |
| title_short | Formation damage due to asphaltene precipitation during CO2 flooding processes with NMR technique |
| title_sort | formation damage due to asphaltene precipitation during co2 flooding processes with nmr technique |
| url | https://doi.org/10.2516/ogst/2018084 |
| work_keys_str_mv | AT qiankun formationdamageduetoasphalteneprecipitationduringco2floodingprocesseswithnmrtechnique AT yangshenglai formationdamageduetoasphalteneprecipitationduringco2floodingprocesseswithnmrtechnique AT douhongen formationdamageduetoasphalteneprecipitationduringco2floodingprocesseswithnmrtechnique AT pangjieqiong formationdamageduetoasphalteneprecipitationduringco2floodingprocesseswithnmrtechnique AT huangyu formationdamageduetoasphalteneprecipitationduringco2floodingprocesseswithnmrtechnique |