石油与天然气地质 ›› 2003, Vol. 24 ›› Issue (2): 162-166.doi: 10.11743/ogg20030212

• 勘探开发 • 上一篇    下一篇

低渗透储层应力敏感性与产能物性下限

王秀娟1,2, 赵永胜2, 文武2, 迟博2, 孙玉2   

  1. 1. 南京大学地球科学系, 江苏南京, 210093;
    2. 大庆油田有限责任公司勘探开发研究院, 黑龙江大庆, 163712
  • 收稿日期:2003-01-13 出版日期:2003-06-25 发布日期:2012-01-16
  • 基金资助:

    国家“九五”重点攻关课题(95-109)“大庆油田年产5300万吨稳产至2000年稳产技术研究”中的子课题“大庆油田地应力场描述及裂缝发育特征研究”部分研究成果

STRESS SENSITIVITY AND POROPERM LOWER LIMIT OF DELIVERABILITY IN THE LOW-PERMEABILITY RESERVOIR

Wang Xiujuan1,2, Zhao Yongsheng2, Wen Wu2, Chi Bo2, Sun Yu 2   

  1. 1. Dep. of Earth Sciences, Nanjing University, Nanjing, Jiangsu;
    2. Exploration and Development Research Institute of Daqing Oilfield Company Ltd., Daqing, Heilongjiang
  • Received:2003-01-13 Online:2003-06-25 Published:2012-01-16

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摘要：

采用CMS-200型孔隙度、渗透率测定仪,对采自大庆长垣东部榆树林、朝阳沟、头台等油田油层的16个岩芯样品进行实验,为了观察油田开发过程中低渗透储层的应力敏感性,选择了初始压力(原始地层压力)和最大围压(最大上覆岩压),并考虑油田注水开发的长期性及岩石本身的流变特性,在实验中适当延长了模拟压力恢复阶段的时间。实验结果表明,低渗透油田储层对应力的变化比较敏感,渗透率降低幅度较大。但随注水时间的延长,渗透率有不同程度的恢复,且恢复程度与渗透率大小有关:初始渗透率高,恢复程度大;初始渗透率低,恢复程度也低。特别是渗透率小于1.0×10-3μm2的储层对应力的变化非常敏感,由此所产生的流固耦合现象也十分明显。因此可将渗透率小于1.0×10-3μm2定为储层应力敏感性的界限。从油田开发角度来看,流固耦合作用的弊大于利,因此开采低渗透储层要尽可能保持地层压力开采,以清除流固耦合的影响。建议在制定储层产能界限时除考虑油层改造及开发技术进步的因素外,也必须考虑流固耦合作用的影响。经过综合分析,指出了大庆长垣东部油田储层的流固耦合作用的影响,并初步将本区的产能界限定为渗透率下限≥1.0×10-3μm2,供油田开发决策参考。

关键词: 低渗透油田, 应力敏感性, 流固耦合, 流变特性, 大庆长垣东部油田

Abstract:

core samples collected from Yushulin,Chaoyanggou and Toutai oilfields to the east of Daqing placanticline have been tested with the CMS-200 porosity and permeability tester.For the sake of observing the stress sensitivity of low permeability reservoir during the oilfield exploitation, initial pressure (initial formation pressure) and maximum confining pressure (maximum overburden pressure)have been chosen;and the recovery time of simulated pressure have properly been prolonged,due to the consideration of the protracted nature of field's waterflood development and the rheological property of the rocks. Experimental results show that the low-permeability reservoir is relatively sensitive to stress change, i.e. the permeability will have a relatively large decrease with the increase of stress.However, permeability has also recovered to a certain degree with the waterflooding to be prolonged, and the degree of recovery is related to the extent of initial permeability: the degree of recovery is greater with higher initial permeability; vice versa. Especially the low-permeability reservoir with permeability of less than 1.0×10-3 μm2 is very sensitive to stress change,and the resulting solid-liquid coupling effect is also very evident.The permeability of 1.0×10-3 μm2 can then be referred to as the limit of reservoir's stress sensitivity.From the viewpoint of oilfield development, the solid-liquid coupling effect will do more harm than good, so exploitation of low-permeability reservoirs should,as far as possible,be kept at the foramtion pressure to eliminate the influence of solid-liquid coupling. Except the factors of reservoir reformation and advanced development technique,the influence of solid-liquid coupling must also be considered while determining the low limit of productivity. It is suggested that the lower limit of productivity can be set at permeability ≥1.0×10-3 μm2 for reference while making strategic decision.

Key words: low-permeability oilfield, stress sensitivity, solid-liquid coupling effect, rheological property, oilfields to the east of Daqing placanticline

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