水平井地质导向着陆段技术分析

Technical Analysis of Geological Steering While Landing for Horizontal Well

水平井作为提高单井产量的有效手段在油气田开发中应用广泛,在构造起伏大、储层厚度薄、横向变化快、连续性差的地区,水平井的地质导向着陆难度大。着陆段地质导向的技术关键是确定轨迹调整策略和相应原则,结合中靶的技术要求,确保着陆在目的层的合适位置。对着陆前的难点和不确定性因素的分析,提出着陆流程和解决方案。通过水平井入层点地层视倾角、目的层深度和入窗井斜角的公式,确定合理的入窗井斜角和靶前轨迹达到落靶要求。该技术已在中国多个油气田水平井着陆中成功应用。

As an effective method to improve single well productivity,horizontal wells are widely used in oil and gas field development.It is very difficult for horizontal well’s landing during geological steering,the challenges include large structural relief,thin reservoir thickness,fast lateral changes and poor continuity.In order to ensure the landing in the appropriate position of the target formation,the key technology to the geological steering difficulties in the landing section is to determine the trajectory adjustment scenario and the corresponding criteria,so as to design the trajectory control strategy integrated with the technical requirements of the target point.By analyzing the difficulties and uncertainty factors in trajectory design before landing,the landing workflow and solutions are put forward.A set of mathematical formulas for calculating the key engineering and geological parameters of the entry point and landing point is proposed,parameters such as vertical depth at entry point,the apparent bed dip,the inclination and incidence layer thickness are calculated.Real-time method of apparent bed dip at entry point are analyzed.The technique has been successfully applied to directional wells in several oil and gas fields in China.