基于全道集叠前反演的页岩气水平井目标靶体储层厚度预测

Pre-Stack Inversion of Target Reservoir Thickness Prediction for Shale Gas Horizontal Wells Based on Full Gathers

摘要: 四川盆地下志留统龙马溪组海相页岩气工作已经进入大规模效益开发阶段，水平井目标靶体段仅为龙马溪底部连续I类优质页岩段。开展连续I类优质页岩段精细预测，引导水平井实钻轨迹准确入靶，确保水平井水平段在箱体中钻进，提高水平井的钻遇率，是页岩气勘探–开发一体化的迫切需要。本论文以四川盆地Z地区为例，将基于全道集叠前同时反演应用于生产实践，预测页岩气水平井目标靶体储层厚度，指导水平井轨迹设计。结果表明：基于全CRP道集叠前同时反演技术充分利用了原始道集中完整的AVO信息，解决了目前页岩气薄层甜点识别的难题，提高了页岩气水平井钻探成功率，降低了勘探开发成本。

Abstract: The marine shale gas in the Lower Silurian Longmaxi Formation in the Sichuan Basin has entered a stage of large-scale profitable development. However, at present, the target section of horizontal shale gas wells is only the continuous type I high-quality shale section at the bottom of Longmaxi. The precise prediction of continuous type I high-quality shale sections is carried out to guide the actual drilling trajectory of horizontal wells to accurately enter the target, so as to ensure that the horizontal section of the horizontal well is drilled in the box, so that the drilling encounter rate of the horizontal well can be improved. This is the urgent need for the integration of rock and gas exploration and development. This thesis takes the Z area of the Sichuan Basin as an example, and applies the pre-stack inversion based on the complete collection data to production practice to finely predict the target reservoir thickness of a shale gas horizontal well, thereby guiding the horizontal well trajectory design. Our research results show that the pre-stack inversion technology based on full CRP gathers makes full use of the complete AVO information of the original gathers, solves the current problem of identifying sweet spots in shale gas thin layers, and improves the success of shale gas horizontal well drilling, and reduce the cost of shale gas exploration and development.