地磁环境下井内装备的磁化磁场强度及影响

邻井套管受到地磁场磁化产生磁化磁场,影响附近的地磁场,并影响测斜仪的磁测量参数,对钻井施工中井眼轨迹防碰和定向施工造成影响。建立了邻近油井为磁干扰源的磁场模型,分析结果表明:竖直井筒在地磁场作用下受到磁化产生的磁化磁场在一定区域内对地磁场产生了干扰,从井筒外壁到距离井筒轴0.5m为强干扰区域,距离井筒轴0.5～2.0m为少量干扰区域,距离井筒轴2～3m为无干扰区域,设计的井间距应2m。

Interference Range of Magnetic Field Strength about Vertical Shaft in Magnetic Environment

Casing of neighboring well will be magnetized by the geomagnetic,which cause a distor- tion of the geomagnetic field around it, and the magnetization have an impact on the magnetic measurement parameters of inclinometer. This situation would have some affection on wellbore anti-collision and the construction of directional wells. By theoretical methods established a model of magnetic interference, as nearby well to be the magnetic interference source, the model analysis showed that the vertical wells in the geomagnetic field are magnetized, the magnetization of the magnetic field generated disturbance the geomagnetic field within a certain region, the distance from the wellbore wall to the well axis O. 5 m stage for the strong interference, from the well axis 0.5~2.0 m stage for the small amount of interference,and from the well axis 2~3 m for the non~ interference phase. The pattern well spacing of design should be greater than 2 m.