塔河油田古岩溶储集体三维建模

3D modeling of paleokarst reservoir in Tahe Oilfield

通过对古岩溶储层建模方法适用性的分析,从加强古岩溶储集体发育模式在建模中的约束作用的角度出发,探索一套'垂向划带、平面分区、断裂优先'的古岩溶储集体三维展布建模方法,将此方法应用于塔河油田4区奥陶系油藏三维建模,并说明该方法的基本步骤,包括单井储集体识别与垂向划带,岩溶古地貌恢复与平面分区,地震约束数据的选用,建模算法与地质统计分析。研究表明:塔河油田4区奥陶系垂向上可以划分为表层岩溶带、垂直渗流溶蚀带、径流溶蚀带及潜流溶蚀带,平面上可分为岩溶高地、岩溶斜坡、岩溶洼地3类岩溶古地貌;古岩溶储集体发育与地震相干体具有较好的概率相关关系;基于'垂向划带、平面分区、断裂优先'方法建立的储集体三维模型与油田生产实践相符。

According to the applicability analysis of paleokarst reservoir modeling method,a method of vertical division of karst zones,planar partition of palaeogeomorphology,fracture as priority was formed,considering the restriction of the development pattern of paleokarst reservoir in the modeling.The primary steps of the method were demonstrated via the case of 3D modeling of Ordovician reservoir in TK4 block of Tahe Oilfield,which were reservoir identification in single well and vertical division of karst zone,restoration and planar partition of palaeogeomorphology,optimization of seismic data as constraint,analysis of modeling algorithm and geologic statistics.The results show that in the vertical direction,the Ordovician reservoir in TK4 block of Tahe Oilfield is divided into superficial karst zone,vertical seepage dissolution zone,runoff dissolution zone and subsurface flow dissolution zone;while in the planar direction,3 types of palaeogeomorphology units were distinguished,which were karst highland,karst slope and karst depression.The paleokarst reservoir has a good probability correlation with seismic coherence,and the 3D model built through the new method is well consistent with the oilfield production.