黄257井区叠前纵波方位各向异性裂缝分布预测

发布时间：2018-04-16 14:40

本文选题：砂岩储层 + 裂缝方向　；参考：《石油地球物理勘探》2017年02期

【摘要】：鄂尔多斯盆地姬塬地区黄257井区延长组地层埋深较大,储层较致密,天然裂缝在改善储层物性方面起到了一定作用。为了研究该区裂缝特征及其影响因素,基于长庆油田采集的60km2三维叠前宽方位角地震资料,利用基于纵波各向异性的相对波阻抗属性开展了延长组裂缝密度和方向的预测。研究表明:(1)叠前相对波阻抗属性预测的裂缝方向与叠后相干、倾角属性分析的断裂方向一致,但深、浅层裂缝方向有变化。长6层和长71小层裂缝主要为北西西向,长72、长73、长8及长9层裂缝方向主要为近南北向。此变化与燕山期和喜山期不同方向应力场作用及长72和长73小层泥岩的塑性变形有关;(2)裂缝的密度整体较低,结合实际测井资料,认为研究区裂缝密度的大小受砂体含量的控制,此控制作用在100m左右的地层段尺度比在30m左右的小层尺度更明显。试油资料分析结果显示,裂缝相对发育区,砂体的含油性受油层厚度和裂缝密度共同影响。以上实践表明,受地震分辨率限制,叠前纵波各向异性裂缝方向和裂缝密度预测的地层单元不宜太薄,目的层厚度大于λ/2(约60m)时预测的结果才更可靠。
[Abstract]:The Yanchang formation of well Huang257 in Jiyuan area of Ordos Basin has a large buried depth and dense reservoir. Natural fractures play a certain role in improving reservoir physical properties.In order to study the fracture characteristics and its influencing factors in this area, based on the seismic data of 60km2 3D prestack wide azimuth angle collected from Changqing Oilfield, the relative wave impedance attribute based on P-wave anisotropy is used to predict the fracture density and direction of the Yanchang formation.The results show that the fracture direction predicted by the prestack relative wave impedance attribute is consistent with that of post-stack coherence and dip attribute analysis, but the direction of deep and shallow fractures varies.The fractures in Chang 6 and Chang 71 are mainly NW-NW, Chang 72, Chang 73, Chang 8 and Chang 9 are nearly north-south.This change is related to the stress field in different directions of Yanshanian and Himalayan periods and the plastic deformation of Chang72 and Chang73 mudstones.It is considered that the size of fracture density in the study area is controlled by the content of sand body, which is more obvious in the strata about 100 m than in the small layer about 30 m.The results of oil testing show that the oil content of sand body is affected by the thickness of oil layer and the density of fracture.The above practice shows that the prestack P-wave anisotropic fracture direction and fracture density prediction should not be too thin due to seismic resolution, and the prediction results are more reliable when the thickness of the target layer is greater than 位 / 2 (about 60 m).
【作者单位】：西北大学大陆动力学国家重点实验室地质学系;中国石油长庆油田分公司勘探开发研究院;中国石油化工股份有限公司石油物探技术研究院;
【基金】：国家自然科学基金重大项目(41390451)资助
【分类号】：P631.4;P618.13

【相似文献】