高压注水条件下泥岩蠕变的数值模拟研究——以大庆喇嘛甸油田北部背斜构造带SⅠ顶泥岩为例

Numerical simulation of mudstone creep under high pressure water flooding: A case study from SⅠmudstone in anticline structure in northern Lamadian Oilfield

主要考虑油层压力变化对上覆泥岩的影响,采用有限差分的方法,对喇嘛甸油田北部背斜构造带SⅠ顶泥岩蠕变进行了模拟研究。结果显示该区域最大水平主应力为近东西向,大小为-25.87～-24.88MPa;最小主应力方向为近南北向,大小为-19.95～-18.44MPa。应变和位移的变化主要表现在垂向上,愈靠近油层部位,受油层压力变化的影响愈大,且泥岩蠕变最大位移量(或应变量)均发生在与油层接触界面处。因此,对泥岩蠕变的最大形变量的研究,有利于油田对岩性层成片套损的预防和控制。

In consideration of the impact of reservoir pressure change on overlying mudstone, finite difference method is applied to carry out the simulation study of mudstone creep on the top of S Ⅰ mudstone in anticline structure in northern Lamadian Oilfield. The result shows that the maximum horizontal principal stress is of-25.87- -24.88 MPa in a direction of near EW, while the minimum principal stress is of -19.95- -18.44 MPa in a direction of near SN. The change of strain and displacement mainly displays in vertical direction. The more near the oil layer, the greater the strain and displacement are impacted by reservoir pressure creep all occurred on the contact interface with the favorable for preventing and controlling casing damage change. The maximum displacement （or variable） of mudstone oil layer. The study of maximum strain of mudstone creep is in oilfield.