CO2混相驱胶质、沥青质析出规律 ——以东河6油藏为例
Gum and asphaltene precipitation pattern in CO2 miscible flooding: A case study of Donghe 6 reservoir
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- 引用格式:
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张利明,李汝勇,袁泽波,侯大力,王小强,曾昌民.CO2混相驱胶质、沥青质析出规律 ——以东河6油藏为例[J].天然气与石油,2024,42(1):63-67.doi:10.3969/j.issn.1006-5539.2024.01.009
ZHANG Liming, LI Ruyong, YUAN Zebo, HOU Dali, WANG Xiaoqiang, ZENG Changmin.Gum and asphaltene precipitation pattern in CO2 miscible flooding: A case study of Donghe 6 reservoir[J].Natural Gas and Oil,2024,42(1):63-67.doi:10.3969/j.issn.1006-5539.2024.01.009
- DOI:
- 10.3969/j.issn.1006-5539.2024.01.009
- 作者:
- 张利明1 李汝勇1 袁泽波1 侯大力2,3 王小强1 曾昌民1
ZHANG Liming1, LI Ruyong1, YUAN Zebo1, HOU Dali2,3, WANG Xiaoqiang1, ZENG Changmin1
- 作者单位:
- 1. 中国石油塔里木油田公司, 新疆 库尔勒 841000; 2. 成都理工大学油气藏地质及开发工程国家重点实验室, 四川 成都 610059; 3. 成都理工大学能源学院, 四川 成都 610059
1. PetroChina Tarim Oilfield Company, Korla, Xinjiang, 841000, China; 2. The State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu University of Technology, Chengdu, Sichuan, 610059, China; 3. College of Energy, Chengdu University of Technology, Chengdu, Sichuan, 610059, China
- 关键词:
- 油层流体混相;CO2混相驱;胶质沉淀;沥青质沉淀;东河6油藏;原油采收率
Reservoir fluid phase mixing; CO2 miscible flooding; Gum precipitation; Asphaltene precipitation; Donghe 6 reservoir; Crude oil recovery rate
- 摘要:
掌握油田原油在注CO2过程中是否混相及油层沥青质的沉淀规律具有重要意义。设计了一套高温、高压混相及沉淀实验装置,并开展CO2混相驱胶质、沥青质析出规律的实验研究,模拟东河6油藏注气开采过程,判断注入气体与地层流体是否达到混相,表征油层内胶质、沥青质的析出规律。实验结果表明:东河6油藏注CO2驱提采机理为一次混相;沥青质相对沉淀量随CO2注入比例的增加而迅速增加后又缓慢减少,胶质相对沉淀量随注入比例的增加先降低后增加;注CO2后降压衰竭开采优先采出饱和烃,油层原油沥青质含量迅速增加。东河6油藏注CO2驱保持最低混相压力45.4 MPa以上开采,可提高驱替效率,减少开采过程中胶质、沥青质的析出,提高原油采收率。研究结果可为注CO2油藏提供一种混相压力及沥青质沉淀测定的方法,支撑注CO2油藏开发方案的制定。
During the CO2 injection process, it's essential to understand whether miscibility significantly impacts oil displacement efficiency and how asphaltene precipitation behaves in oil layers under CO2 injection. This paper outlines the design of a high-temperature and high-pressure mixing and precipitation experimental apparatus and details experimental studies on the precipitation pattern of asphaltenes and resins during CO2 miscible flooding. The research simulates the injection and production processes of the Donghe 6 reservoir, assessing the miscibility of the injected gas with the formation fluid and monitoring the precipitation pattern in asphaltene and resin content within the reservoir. The experimental results indicate that the CO2 flooding mechanism in the Donghe 6 reservoir is primarily of the contact miscible type. The relative precipitation of asphaltenes initially surges and then tapers off with increasing amounts of injected CO2, whereas the precipitation of resins first diminishes and then rises. After the CO2 injection, employing depressurization and depletion techniques preferentially extracts saturated hydrocarbons, resulting in a marked increase in asphaltene concentration in the reservoir's crude oil. To enhance displacement efficiency and mitigate resin and asphaltene precipitation during extraction, maintaining a minimum miscibility pressure of 45.4 MPa or higher for CO2 flooding in the Donghe 6 reservoir is recommended, which also contributes to an elevated crude oil recovery rate. The research results provide a method for measuring miscibility pressure and asphaltene precipitation in reservoirs undergoing CO2 injection, thereby supporting the development strategies for such reservoirs.
