基于声学数据反演定量评价致密砂岩储层微裂隙应力敏感性新方法

发布时间：2018-01-21 21:59

本文关键词： 塔中地区声学反演致密砂岩储层微裂隙应力敏感性　出处：《岩土力学》2017年02期 　论文类型：期刊论文

【摘要】：设计试验方法流程对塔中地区深层致密砂岩储层岩样进行不同围压条件下声学测试,提出基于声学数据反演定量研究致密砂岩储层微裂隙应力敏感性的评价方法。通过Biot相洽理论和DEM理论组合模型分别对岩石裂隙密度?和孔隙纵横比?进行反演,探讨了不同围压条件下岩石?、?的变化规律,并对微裂隙应力敏感性进行评价。结果表明:?随围压的增加而降低,?随围压的增加而增加,这主要是由于微裂隙的闭合引起的;根据不同围压条件下?值降低幅度可以确定发生闭合的裂隙或依然保持张开的裂隙所占的百分比;在较高围压条件下依然具有较大?值的样品应力敏感性较弱,反之,应力敏感性较强;定义试验中岩石内部孔裂隙性质发生急剧变化的点为转折点,发现该点对应的?值相差不大,该值可视为该致密砂岩储层的裂隙共性特征,并可作为裂隙相对发育程度的对比指标;分别探讨了?值(围压65 MPa)及所定义转折压力与岩石孔隙度间的相关性,结果表明,两者正相关性均非常好,对于该地区深层低渗致密砂岩储层而言,存在低应力敏感性的有利类型裂隙受岩石物理性质影响程度最大。
[Abstract]:The flow of design test method is used to test the rock samples of deep tight sandstone reservoir in Tazhong area under different confining pressure conditions. An evaluation method for the stress sensitivity of microfractures in tight sandstone reservoirs based on acoustic data inversion is proposed. The rock fracture density is evaluated by Biot consistent theory and DEM theory combination model. To the aspect of the pore? By inversion, the rock under different confining pressure is discussed. ,? And the stress sensitivity of microfracture was evaluated. Decrease with the increase of confining pressure? It increases with the increase of confining pressure, which is mainly caused by the closure of microcracks. The percentage of closed or still open fissures can be determined by the magnitude of the decrease in values; still larger under higher confining pressures? On the other hand, the stress sensitivity of the sample is relatively weak, whereas the stress sensitivity of the sample is relatively strong, and the turning point is defined as the point at which the property of the pore and fissure in the rock changes dramatically in the test, and the corresponding point is found. This value can be regarded as the common characteristics of fractures in the tight sandstone reservoir, and can be used as a comparative index of the relative development degree of fractures. The correlation between the values (confining pressure 65 MPA) and the defined turning pressure and rock porosity shows that the positive correlation between them is very good for the deep low permeability tight sandstone reservoirs in this area. The favorable types of fractures with low stress sensitivity are most affected by the physical properties of rocks.
【作者单位】：中国地质大学能源学院;中国地质大学海相储层演化与油气富集机理教育部重点实验室;中国地质大学页岩气资源战略评价国土资源部重点实验室;成都理工大学油气藏地质及开发工程国家重点实验室;
【基金】：国家自然科学基金项目(No.41572130,No.41372139,No.41072098) 国家科技重大专项专题(No.2016ZX05046-003-001,No.2011ZX05018-001-002,No.2011ZX05009-002-205,No.2011ZX05033-004)~~
【分类号】：P618.13
【正文快照】： 1 引言油气储层的应力敏感性主要指储层岩石的物性特征随应力环境的变化而发生变化的性质[1],Fatt等[2-3]最早发现储层岩石的渗透率应力敏感性之后,许多学者对此进行了大量研究[4-6]。对于低渗致密砂岩油气藏而言,大多数研究均表明,该类型储层具有较强的裂缝应力敏感性,同时

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