西南石油大学学报(自然科学版) ›› 2016, Vol. 38 ›› Issue (6): 131-137.DOI: 10.11885/j.issn.1674-5086.2014.12.15.03

• 石油与天然气工程 • 上一篇    下一篇

CO2驱低液量高气液比井下气锚模拟与优化

刘永辉1, 张楠1, 潘若生2, 张德平2, 王武兵3   

  1. 1. 西南石油大学石油与天然气工程学院, 四川 成都 610500;
    2. 中国石油吉林油田采油工艺研究院, 吉林 松原 138000;
    3. 陕西延长石油国际勘探开发工程有限公司, 陕西 西安 710000
  • 收稿日期:2014-12-15 出版日期:2016-12-01 发布日期:2016-12-01
  • 通讯作者: 刘永辉,E-mail:swpilyh@126.com
  • 作者简介:刘永辉,1977年生,男,汉族,四川仁寿人,副教授,博士,主要从事采油采气工程领域的教学和科研工作。E-mail:swpilyh@126.com;张楠,1987年生,男,汉族,山东沾化人,博士研究生,主要从事采油采气工艺研究。E-mail:zhnorn@126.com;潘若生,1985年生,男,汉族,吉林松原人,工程师,硕士,主要从事CO2驱采油技术研究工作。E-mail:panrsh-jl@petrochina.com.cn;张德平,1980年生,男,汉族,吉林松原人,工程师,硕士,主要从事CO2驱采油技术研究工作。E-mail:zhangdepjl@petrochina.com.cn;王武兵,1986年生,男,汉族,河南郾城人,助理工程师,硕士,主要从事采油采气工艺研究。E-mail:wangwb9898@163.com
  • 基金资助:
    国家科技重大专项(2011ZX05054002-002)。

Simulation and Optimization of Downhole Gas-Liquid Separator at Low Liquid Rate and High GLR Wells From CO2 Flooding Reservoir

LIU Yonghui1, ZHANG Nan1, PAN Ruosheng2, ZHANG Deping2, WANG Wubing3   

  1. 1. School of Petroleum and Natural Gas Engineering, Southwest Petroleum University, Chengdu, Sichuan 610500, China;
    2. Production Technology Research Institute, Jilin Oilfield Company, PetroChina, Songyuan, Jilin 138000, China;
    3. International Exploration and Development Engineering Company, Shaanxi Yanchang Petroleum Co. Ltd., Xi'an, Shaanxi 710000, China
  • Received:2014-12-15 Online:2016-12-01 Published:2016-12-01

摘要: 注CO2驱油已在吉林油田开发低渗透油藏中取得了良好效果,其采油井出现典型的小液量、高气液比特征,导致在常规油井中运行良好的有杆泵采油工艺出现了较强的不适应性。为此,在分析常规重力类气锚和螺旋气锚分气原理的基础上,设计了适用于低液量高气液比的新型井下气锚结构,采用抽油机悬点运动规律作为抽油泵工作过程,修正了CFD模型的上边界条件,将地面气液比修正为入泵气液比并考虑气泡的破碎和凝聚,模拟了新型井下气锚工作原理,单因素敏感分析了柱塞的抽汲参数对新型井下气锚分气效率的影响。X井现场试验表明,采用新型井下气锚后,井口套压由9.5 MPa降至0.4 MPa,产液量由措施前的1.5 t/d升至17.4 t/d,在产气量达到792 m3/d情况下,泵效高达84.6%,明显高于同区块其余井平均泵效40.1%。该研究成果对于CO2驱油的推广应用具有重要现实意义,对类似的高气液比油井有杆泵抽油具有重要的借鉴作用。

关键词: CO2驱, 低渗透油藏, 井下气锚, 计算流体动力学, 数值模拟分析

Abstract: CO2 flooding technology was well applied in low permeability reservoirs in Jilin Oilfield, where production wells are characterized by small liquid rate and high gas liquid ratio, which has a serious effect on the sucker rod pump system, such as low pump efficiency. Aiming at dropping the gas rate pumped into sucker rod in those wells, we developed a new downhole gas-liquid separator on the basis of gas separation principle of the conventional gravity type gas anchor and that of spiral gas anchor. In this paper, CFD is improved to optimize its parameters. Suspended point motion of pump unitsis taken as boundary conditions of the motion pump, the surface gas-liquid ratio is replaced by the gas-liquid ratio and bubble breakage and aggregation are taken into consideration. The swabbing parameters of sucker rod pump were selected to get its high efficiency. The new downhole gas-liquid separator was installed at Well X. The casing pressure dropped from 9.5 MPa to 0.4 MPa, daily liquid production rate increased from 1.5 t/d to 17.4 t/d, and the pump efficiency was 84.6% when the daily gas volume rate is 792 m3/d. Its pump efficiency is higher than the average pump efficiency of 40.1% of other wells in the same block. The study has important practical significance in application of CO2 flooding and has an important reference in similar high gas liquid ratio wells with sucker rod pump.

Key words: CO2 drive, low permeability reservoir, downhole gas-liquid separator, computational fluid dynamics, simulated analysis

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