石油与天然气地质 ›› 2023, Vol. 44 ›› Issue (4): 1044-1053.doi: 10.11743/ogg20230419

• 方法技术 • 上一篇    下一篇

塔里木盆地超深油气藏流体相行为变化特征

胡伟1,2(), 徐婷2, 杨阳1,2, 伦增珉1,2, 李宗宇3, 康志江2, 赵瑞明3, 梅胜文3   

  1. 1.页岩油气富集机理与有效开发国家重点实验室, 北京 102206
    2.中国石化 石油勘探开发研究院, 北京 102206
    3.中国石化 西北油田分公司, 新疆 乌鲁木齐 830011
  • 收稿日期:2022-12-05 修回日期:2023-05-26 出版日期:2023-08-01 发布日期:2023-08-09
  • 第一作者简介:胡伟(1988—),男,博士、副研究员,非常规油气流体相态表征。E-mail: huwei.syky@sinopec.com
  • 基金项目:
    国家自然科学基金企业创新发展联合基金项目(U19B6003-02-06);中国石化科技部攻关项目(P22030)

Fluid phases and behaviors in ultra-deep oil and gas reservoirs, Tarim Basin

Wei HU1,2(), Ting XU2, Yang YANG1,2, Zengmin LUN1,2, Zongyu LI3, Zhijiang KANG2, Ruiming ZHAO3, Shengwen MEI3   

  1. 1.State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development,Beijing,102206,China
    2.Petroleum Exploration and Production Research Institute,SINOPEC,Beijing 102206,China
    3.Northwest Oil Field Company,SINOPEC,Urumqi,Xinjiang 830011,China
  • Received:2022-12-05 Revised:2023-05-26 Online:2023-08-01 Published:2023-08-09

摘要:

超深储层复杂的地质条件导致流体相态特征呈现多样性和多变性,为勘探开发带来了极大挑战。以塔里木盆地顺北地区为例,通过建立超深油气藏流体相态研究方法,采用等时间间隔井下取样方法,在获取不同生产阶段地层流体样品的基础上,研究了典型油气井地层流体的相行为变化特征,并通过开展两期充注流体混合开发沥青质沉积实验,揭示了凝析气井发生沥青质沉积的原因,从流体相变角度提出了合理开采建议。研究结果表明,顺北4号断裂带D1井钻遇的断溶体存在深部原油供给,垂向上呈现上气下油的组分梯度变化,开采过程中地层流体类型由凝析气向近临界态凝析气、再向挥发油转变。反凝析后的凝析油来源于两期充注流体,一是凝析气中自含的凝析油,另一小部分来自于深部原油被凝析气抽提出的轻质组分。而D2井钻遇断溶体为单一封闭凝析气藏,其相态变化规律与常规凝析气相近。D1井出现的沥青质沉积与上部凝析气和深部原油被同时动用有关,当凝析气与深部原油混合开采时,会导致沥青质沉积起始压力和沉积量大幅增加,加剧沥青质在储层和井筒中沉积。建议采用先油藏后气藏、保压方式开采上气下油型断溶体油气藏。取得的成果为超深油气藏高效勘探开发提供了参考和借鉴。

关键词: 沥青质, 两期充注, 相行为, 断溶体, 凝析气, 超深层, 塔里木盆地

Abstract:

The complex geological conditions of ultra-deep reservoirs lead to the diversity and variability of fluid phase characteristics, imposing great challenges to oil and gas exploration and development. This study established a method for studying the fluid phase behaviors of ultra-deep oil and gas reservoirs in the Shunbei area of Tarim Basin through the equal-time-interval downhole sampling to obtain formation fluid samples at different production stages. During the process, the causes of asphaltene deposition in gas condensate wells were revealed by experiments of asphaltene deposition during commingled recovery of hydrocarbon fluids charged in two stages, and suggestions for optimal recovery scheme were put forward from the point of view of fluid phase change. The results show that the fault-karst bodies encountered by Well D1 in the Shunbei No.4 fault zone are receivers of deep oil supply, showing a vertical composition gradient with gas upon oil. The hydrocarbon fluid phase changes first from condensate gas to gas of near critical condensate saturation and finally to gas condensate (volatile oil), with the latter being the result of mixing of hydrocarbon fluids charged in two stages: the crude contained in condensate gas and the light components extracted by gas from deep crude. The fault-karst body penetrated by Well D2 contains only a closed gas reservoir with hydrocarbon fluid phase changing in a way similar to that of a conventional condensate gas reservoir. The asphaltene deposition in Well D1 is suggested to be related to its commingled production with deep crude, which could lead to the significant increase in initiation pressure and volume of asphaltene deposition within the reservoir and the wellbore. A production scheme that extracts oil before gas with reservoir pressure well controlled is therefore recommended for such gas-over-oil fault-karst reservoirs. The results are of great reference value for the exploration and production of ultra-deep oil and gas reservoirs.

Key words: asphaltene, two-stage charging, phase behavior, fault-karst body, condensate gas, ultra-deep layer, Tarim Basin

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