叠前反演技术在公山庙高密度三维区块致密砂岩储层预测及抽稀试验中的应用

Application of pre-stack inversion technology in tight sandstone reservoir prediction and thinning test in Gongshanmiao high-density 3D block

针对公山庙高密度三维区块沙溪庙组储层与围岩阻抗差异小及高密度采集成本与勘探效果难以平衡的问题,本文首先利用基于Xu-White模型的横波预测、近中远道精细储层标定和岩石物理模板的建立等叠前反演关键技术,进而通过叠前同时反演对工区内具有潜力的3号大型规模河道进行定量预测,以此指导井位部署。其次,较小的地层倾角及较小的的地震速度变化为抽稀地震成像成果数据指导地震采集设计提供了可能性,因此依据面元和覆盖次数设计了抽稀后的3种不同观测系统。然后为使各套数据没有时差,抽稀后的观测系统采用高密度数据的约束层析静校正量,其余处理参数参照高密度处理流程进行调整,并分析不同观测系统情况下对地震资料品质的影响。最后结合不同的观测系统设计对应的反演流程,分别从纵向分辨率与横向分辨率对各个观测系统识别不同规模河道的能力进行评价,综合考虑有效性和经济型,依次优选出一套与高密度数据识别效果相当的观测系统。本次研究的抽稀试验期望从叠前反演的角度为该地区最佳观测系统论证提供技术支撑。

Aiming at the problem that the impedance difference between the reservoir and surrounding rock of the Shaximiao Formation in the Gongshanmiao high-density 3D block is small, and the high-density acquisition cost and the exploration effect are difficult to balance,this paper first uses the shear wave prediction based on the Xu-White model. The key technologies of pre-stack inversion, such as reservoir calibration and the establishment of petrophysical templates, are used to quantitatively predict the potential large-scale channel No.3 in the work area through simultaneous pre-stack inversion to guide the deployment of well locations. Secondly, the smaller stratum dip and the smaller seismic velocity change provide the possibility to dilute the seismic imaging result data to guide the seismic acquisition design.Therefore, three different observation systems after diminution are designed based on the bin and the number of coverages. Then, in order to make each set of data have no time difference,the observing system after thinning adopts the constrained tomographic static correction amount of high-density data, and the remaining processing parameters are adjusted with reference to the high-density processing flow, and then analyze the influence of different observation systems on the quality of seismic data, and designe corresponding inversions in combination with different observation systems Process. This article evaluates the ability of each observation system to identify rivers of different scales from the vertical and horizontal resolutions,comprehensively considering effectiveness and economy, a set of observation systems equivalent to the recognition effect of high-density data is selected successively. The thinning test in this study is expected to provide technical support for the demonstration of the best observation system in this area from the perspective of pre-stack inversion.