利用斜井井壁破坏信息计算最大水平地应力

发布时间：2018-06-26 17:48

  本文选题：斜井 + 井壁崩落　； 参考：《断块油气田》2017年05期

【摘要】：准确获取深部地层的地应力大小和方向,对于安全钻井作业、控制井筒出砂和压裂增产至关重要。利用井壁破坏信息计算地应力的方法已得到广泛认同,甚至已建立了利用井壁崩落宽度计算最大水平地应力的模型,但是该计算模型仅限于直井井壁破坏。为此,根据线性多孔弹性岩石力学理论,确定了任意斜井井壁崩落位置和张性裂缝位置,找出了间接计算最大水平地应力的方法,即利用斜井井壁崩落和张性裂缝建立地应力和岩石强度的关系图版,根据实际岩石强度确定最大水平地应力。利用该方法对川西南部斜井成像测井观测到的井壁破坏信息进行了实例分析,分析结果表明,该地区垂深4 663.5 m处的最大水平地应力为178.9~180.3 MPa。川西南部地区正处于逆断层地应力状态,在较强的水平挤压应力作用下,该地区的原生断层接近摩擦极限应力状态,断层容易滑动,因此该地区地震频发。利用该方法可以根据任意斜井井壁的破坏情况计算最大水平地应力,扩展了斜井成像测井资料的应用范围。
[Abstract]:It is very important to accurately obtain the magnitude and direction of in-situ stress in deep formation for the safe drilling operation and the control of wellbore sand production and fracturing production. The method of calculating in-situ stress based on wellbore failure information has been widely accepted, and even a model has been established to calculate the maximum horizontal in-situ stress using wellbore caving width, but the calculation model is limited to vertical wellbore failure. Therefore, according to the theory of linear porous elastic rock mechanics, the caving position and tensile fracture position of arbitrary inclined shaft wall are determined, and the method of indirectly calculating the maximum horizontal stress is found. The relationship between in-situ stress and rock strength is established by using inclined shaft wall caving and tensile fracture, and the maximum horizontal in-situ stress is determined according to the actual rock strength. By using this method, the damage information of borehole wall observed by imaging logging in southwestern Sichuan is analyzed. The results show that the maximum horizontal stress at 4 663.5 m vertical depth in this area is 178.9 m 180.3 MPA. The southern part of Sichuan is in the state of in-situ stress of the reverse fault. Under the action of strong horizontal compression stress, the primary fault in this area is close to the state of frictional limit stress, and the fault is easy to slip, so the earthquake occurs frequently in this area. By using this method, the maximum horizontal stress can be calculated according to the failure of the sidewall of any inclined well, and the range of application of the imaging logging data in the inclined well can be extended.
【作者单位】： 西南石油大学石油与天然气工程学院;
【基金】：国家科技重大专项“准噶尔盆地致密油开发示范工程”(2017ZX05070)
【分类号】：TE21
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本文编号：2070878