哥伦比亚Llanos盆地东部油田Carbonera组C5段河道砂岩地震识别与预测

摘要

The channels developed in the Micocene Carbonera formation in the eastern part of the Llanos basin, Columbia, are so favorable reservoir that the accurate descriptions for these channels are key issues in this area.Guided by the simulation of wave equation, the seismic identification mode for channel sand is established.The distribution of the channels is then predicted with RGB mixing frequencies data slices and sensitive attributes.Eventually, the thickness and porosity of sand body are quantitatively described, using constrained sparse impulse inversion and geostatistical inversion.In our study, five favorable lithologic traps of channel sandstone are described in detail.The width of channel is about 322~830 m, and the thickness for channel sand ( with porosity larger than 18%) is 35.05 m, which make this channel sand favorable prospecting areas.The result of the drilling W2 verifies the validity of the technique and the reliability of the reservoir description, which provides a new direction for exploration and development in the next step.%哥伦比亚Llanos盆地东部的中新世Carbonera组属于三角洲前缘相沉积. Carbonera组内部的水下分流河道砂体是良好的储层,因此对河道的精细刻画有利于指导下一步的油气勘探和开发.研究通过波动方程波场正演模拟建立了河道砂岩储层的地震识别模式,并利用地震沉积学RGB混频体地层切片以及沿层地震振幅属性对河道的形态、发育期次、以及砂体的平面分布进行了详细的研究.在此基础上,利用约束稀疏脉冲反演和地质统计学反演研究定量描述了河道砂体的孔隙度和厚度.最终对五条有利的河道砂岩岩性圈闭进行了详细的描述,研究区河道的宽度为322~830 m、砂岩最厚可达到35.05 m,这些河道砂体可为有利勘探目标区.区内钻探的W2井证实了该技术方法的有效性和储层描述结果的可靠性,为研究区下步的油气勘探开发提供新方向.