油气藏评价与开发 ›› 2019, Vol. 9 ›› Issue (1): 44-50.

• 石油工程 • 上一篇    下一篇

淀粉接枝共聚物凝胶堵水效果及作用机理研究

曹伟佳1,卢祥国1,张云宝1,2,徐国瑞3,李翔3   

  1. 1. 东北石油大学提高油气采收率教育部重点实验室,黑龙江 大庆 163318
    2. 中海石油(中国)有限公司天津分公司渤海石油研究院,天津 300450
    3. 中海油田服务股份有限公司天津分公司,天津 300452
  • 收稿日期:2018-03-16 出版日期:2019-02-26 发布日期:2019-02-15
  • 作者简介:曹伟佳(1992—),女,在读博士研究生,调剖、堵水和化学驱技术研究。
  • 基金资助:
    国家科技重大专项“渤海双高油田多级窜逸堵调驱一体化技术研究及示范”(2016ZX05058-003-010);国家自然科学基金“抗盐型聚合物油藏适应性及其改进方法基础研究”(51574086)

Study on water plugging effect and mechanism of starch graft copolymer gel

Cao Weijia1,Lu Xiangguo1,Zhang Yunbao1,2,Xu Guorui3,Li Xiang3   

  1. 1. Key Laboratory of Enhanced Oil Recovery of Education Ministry, Northeast Petroleum University, Daqing, Heilongjiang 163318, China
    2. Bohac Oilfield Research Institute, Tianjin Branch, CNOOC(China) Ltd., Tianjin 300450, China
    3. Tianjin Branch, COSL, Tianjin 300452, China
  • Received:2018-03-16 Online:2019-02-26 Published:2019-02-15

摘要:

渤海油田具有储层岩心胶结疏松、非均质性严重、原油黏度较高、平均渗透率较高和单井注水量较大等特点,注水开发不仅极易发生突进,而且注水开发对岩石结构冲刷和破坏作用会进一步加剧储层非均质性。为满足高含水期稠油油藏堵水技术需求,以物理化学、高分子材料学和油藏工程等为理论指导,以化学分析、仪器检测和物理模拟等为实验手段,以渤海SZ36—1油田储层岩石和流体为研究对象,开展了淀粉接枝共聚物凝胶堵水效果及作用机理研究。结果表明,当堵水剂组成为“4 %淀粉+4 %丙烯酰胺+0.036 %交联剂+0.012 %引发剂+0.002 %无水亚硫酸钠”时,堵水剂合理段塞尺寸在0.025 PV~0.075 PV。对于“边水+直井”模型,随原油黏度增加,水驱采收率降低。油井堵水后,含水率降低,但产液速度降低。原油黏度愈高,含水率降幅愈大,采收率增幅愈大,但最终采收率仍然较低。与“单边水+直井”模型相比较,“多边水+直井”模型水驱采收率较高,堵水增油降水效果更好。对于处于中高含水开发期油藏,由于前期水驱、调剖和化学驱等措施的影响,水井井壁附近区域剩余油饱和度较低,而油井井壁附近中低渗透层剩余油饱和度较高。因此,堵水措施增油降水效果要明显好于调剖措施的效果。

关键词: 海上稠油油藏, 堵水效果, 参数优化, 物理模拟, 机理探讨

Abstract:

Bohai oilfield has the characteristics of loose cementation, serious heterogeneity, high viscosity of crude oil, high average permeability and large amount of water injection in a single well. The breakthrough phenomenon of water injection development was serious, and the injection water erosion also caused damage to rock structure. Then we formed inefficient and ineffective circulation between injection and production wells, seriously affecting the effect of water flooding development, and bringing great risks to subsequent chemical flooding development. In order to satisty the heavy oil reservoir of high water shutoff technology needs, based on the physical chemistry, polymer materials and reservoir engineering theory, and taking the chemical analysis, detection equipment and physical simulation as an experimental method, we took the reservoir rock and fluid in SZ-361 field of Bohai oilfield as the research object to study the water plugging effect and mechanism of starch graft copolymer gel. The results showed that when the water plugging agent group was "starch(4 %)+ acrylamide(4 %) + crosslinking agent(0.036 %) + initiator(0.012 %) +anhydrous sodium sulfite(0.002 %)", the reasonable slug size of water plugging agent was between 0.025PV and 0.075PV. For the model of "edge water and vertical oil well", the oil recovery of water flooding decreases with the increase of crude oil viscosity. After water plugging in the oil well, the liquid production rate decreases when the water content drops. The higher the viscosity of crude oil is, the greater the decline of water content and the recovery rate will be, but the ultimate recovery is still lower. Compared with the model of "single water and vertical oil well", the model of "multilateral water and vertical oil well" had higher water flooding recovery, and the effect of water plugging and oil increasing was better. For the high water cut development period of reservoir, due to the impact of early water flooding and chemical flooding profile control and other measures, the remaining oil saturation near the water wells borehole area was low, but the residual oil saturation in low permeability reservoirs near the wellbore was higher. Therefore, the effect of water plugging measures on increasing oil and precipitation was much better than that of profile control measures.

Key words: offshore heavy oil reservoir, water plugging effect, parameter optimization, physical simulation, mechanism study

中图分类号: 

  • TE39