反演约束的多点地质统计学建模——以大庆长垣陆相油田为例  

Multi-point geostatistical modeling with inversion constraints:a case study of continental oil fields in Daqing placanticline

作　　者：黄勇[1] 徐立恒[1] 杨会东[1] 何秋丽[1] 何宇航[1] 杨庆杰[1] HUANG Yong;XU Liheng;YANG Huidong;HE Qiuli;HE Yuhang;YANG Qingjie(Exploration and Development Research Institute of Daqing Oilfield Co.,Ltd.,Daqing,Heilongjiang 163712,China)

机构地区：[1]大庆油田有限责任公司勘探开发研究院,黑龙江大庆163712

出　　处：《石油地球物理勘探》2022年第6期1445-1452,I0008,共9页Oil Geophysical Prospecting

基　　金：国家科技重大专项“大庆长垣特高含水油田提高采收率示范工程”(2016ZX05054)资助。

摘　　要：针对陆相油田沉积横向变化快、砂体规模小、剩余油分布零散难题,采用地震反演约束的多点地质统计学建模方法,实现砂体空间三维精准表征,指导老油田剩余油挖潜。具体步骤为:首先,建立了河流—三角洲相的3种分流河道砂体、2种非河道砂体平面组合模式的“训练图像”;其次,明确了不同沉积微相的纵波阻抗特征,即纵波阻抗低值反映了河道砂体,高值反映了河间泥,而河间砂的纵波阻抗值介于河道砂体和河间泥之间,并采用波形指示反演方法得到了纵波阻抗数据体;最后,利用训练图像替代变差函数进行模式引导,以纵波阻抗反演数据体控制井间趋势,实现多点地质统计学沉积微相精细建模。结果显示:多点地质统计学方法(与常规建模方法相比)能够清晰地描述河道的几何形态、宽度及砂体接触关系,砂体间连通关系更明确、无效网格更少,河道砂体平均预测精度由79.6%提高至86.1%;基于建模结果,确定了研究区剩余油潜力部位,指导挖潜措施显现较好效果。因此,地震反演约束的多点地质统计学建模方法能够满足陆相油田储层精细描述及剩余油精准挖潜需求。In view of the problems of rapid lateral change of sedimentation,small sand-body scale,and scattered distribution of remaining oil in continental oil fields,the multi-point geostatistical modeling method constrained by seismic inversion is adopted to realize the three-dimensional accurate representation of sand-body space and guide the remaining-oil potential tapping of old oil fields.Specific steps are as follows:Firstly,the“training images”are constructed for plane combination modes of three distributary channel sand bodies and two non-channel sand bodies of the river-delta facies.Secondly,the P-wave impedance characteristics of different sedimentary microfacies are defined.In other words,the channel sand body features low P-wave impedance,and the inter-river mud features high P-wave impedance,while that of inter-river sand is between the two.The P-wave impedance data volume is obtained by the waveform-indication inversion method.Finally,the training images are used to replace the variation function for mode guidance,and the inversion data volume of P-wave impedance is used as the interwell trend control to achieve the fine modeling of multi-point geostatistical sedimentary microfacies.The results show that the multi-point geostatistics method(compared with the conventional modeling method)can clearly describe the geometric shape,width,and sand-body contact relationships of channels,and the connection relationship between sand bodies is more clear,with fewer invalid grids.The average prediction accuracy of channel sand bodies is improved from 79.6%to 86.1%.Given the modeling results,the potential positions of remaining oil in the study area are identified,and the measures to guide potential tapping have achieved good results.This indicates that the method in this paper can meet the needs of fine reservoir description and accurate potential tapping of remaining oil in continental oil fields.

关 键 词：多点地质统计学 地震反演 建模 训练图像 陆相油田 大庆长垣 

分 类 号：P631[天文地球—地质矿产勘探]