利用骨架砂体叠加图进行储层预测

针对薄砂层地区油气勘探中,地震资料分辨率达不到储层预测的精度,又无测井资料进行直接预测的情况,为了降低勘探风险,必须进行储层的预测和圈闭的综合评价。在吐哈盆地胜南合作区块的滚动勘探中,采用了精细沉积微相分析技术,对勘探目标区各小层沉积微相进行了分析,编制了各层的砂体分布图;将各层砂体中水下分流河道主力砂体提取出来,编制了各小层水下分流河道砂体的叠加图。通过对叠加图中各水下分流河道砂体叠加情况的分析,确定了优势储层分布区域。以砂体分布为基础,结合油藏断层的封闭性、油气运移的优势路径,对各砂体发育区所在的圈闭进行了成藏风险评价,提出了勘探建议,在一定程度上规避了勘探风险,收到了较好的效果。

Application of sand body framework superposed graph to reservoir prediction

In the exploration of the found reservoir with thin sand, the seismic data were quite inadequate for reservoir prediction, and the well logs could not be sufficient to deduce a reasonable sand body distribution. But reservoir prediction and evaluation must be done for reducing the risk of exploration. In the progressive exploration of Shengnan Block in Tuha Basin, the detailed micro-facies analysis and superposed graph were used to evaluate the targets. The micro facies of all the layers in the reservoir were analyzed, and the distribution maps of sand body of each layer were made. The target zone belongs to braided delta deposition, and the distributary channel is the most important sedimentary facies in the sand framework. The subaqueous distributay channels in all layers were predicted on the micro-facies analysis. All the distributary channel sand bodies on a single graph were superposed, and the reservoir frame sand thickness was evaluated with the superposed graph. The favorable traps of developed sand body were fixed on the channel sand thickness, fault sealness, hydrocarbon supply and its migration way. Using the study results, some wells were designed for exploring the found reservoir edge and new small fault blocks. The sand body distribution revealed by drilled wells is coincident with the result of micro-facies analysis.