新疆石油地质 ›› 2024, Vol. 45 ›› Issue (3): 327-333.doi: 10.7657/XJPG20240309

• 油藏工程 • 上一篇    下一篇

玛湖凹陷致密砾岩油藏不同开发方式下原油微观可动性

万涛1(), 张景2, 董岩2   

  1. 1.中国石油大学(北京)克拉玛依校区 石油学院,新疆 克拉玛依 834000
    2.中国石油 新疆油田分公司 勘探开发研究院,新疆 克拉玛依 834000
  • 收稿日期:2023-12-13 修回日期:2024-01-08 出版日期:2024-06-01 发布日期:2024-05-23
  • 作者简介:万涛(1988-),男,江西南昌人,教授,博士,油气田开发,(Tel)0990-6633531(Email)2017592002@cupk.edu.cn
  • 基金资助:
    新疆维吾尔自治区自然科学杰出青年基金(2022D01E55);新疆维吾尔自治区“天山英才”青年拔尖人才项目基层科技骨干人才(2023TSYCJC0002)

Microscopic Oil Mobility in Tight Conglomerate Reservoirs Under Different Development Modes, Mahu Sag

WAN Tao1(), ZHANG Jing2, DONG Yan2   

  1. 1. School of Petroleum, Karamay Campus, China University of Petroleum (Beijing), Karamay, Xinjiang 834000, China
    2. Research Institute of Exploration and Development, Xinjiang Oilfield Company, PetroChina, Karamay, Xinjiang 834000, China
  • Received:2023-12-13 Revised:2024-01-08 Online:2024-06-01 Published:2024-05-23

摘要:

为评价玛湖凹陷三叠系百口泉组致密砂砾岩油藏原油可动性,通过渗吸、离心以及吞吐试验,对比了Ⅰ类和Ⅱ类储集层的典型岩心样品可动油分布特征。玛湖凹陷低渗透砾岩储集层渗吸出油量与孔隙结构有关,小孔隙体积占比越高,渗吸效果越好,经过144 h渗吸驱油,采收率可达30.9%,但是驱油进程缓慢,对大孔隙原油动用程度不高。在地层温度和40 MPa压力下,在3轮次CO2吞吐过程中,每轮次的采出程度均增加,第1轮次采出程度增幅相对较高,换油率达27%,随着吞吐轮次的增加,采出程度增幅逐渐降低,而N2吞吐开发第1轮次换油率为15%,因此,CO2吞吐开发效果较好。

关键词: 玛湖凹陷, 百口泉组, 致密砾岩油藏, 可动油饱和度, 核磁共振, 驱油效率

Abstract:

In order to evaluate the oil mobility in the tight sandy conglomerate reservoirs of the Triassic Baikouquan formation in the Mahu sag, the distribution characteristics of movable oil in typical rock samples from Type Ⅰ and Type Ⅱ reservoirs were compared through imbibition, centrifugation, and huff-n-puff tests. For the low-permeability conglomerate reservoirs in the Mahu sag, the imbibition oil recovery is related to the pore structure of the rock. The higher the proportion of small pores, the better the imbibition effect. After 144 hours of oil displacement by imbibition, the recovery rate can reach 30.9%, but the oil displacement process is slow, with low utilization of large pores. Under reservoir pressure of 40 MPa and reservoir temperature, during three cycles of CO2 huff-n-puff process, the recovery percent of each round increase, with the highest increase observed in the first cycle, reaching an oil exchange ratio of 27%. As the huff-n-puff cycle increases, the increment in recovery percent gradually decreases, and the oil exchange ratio of N2 huff-n-puff in the first cycle is 15%. Therefore, CO2 huff-n-puff has the best development effect.

Key words: Mahu sag, Baikouquan formation, tight conglomerate reservoir, movable oil saturation, NMR, displacement efficiency

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