密井网区河道砂体井网控制程度认识——大庆萨尔图油田中区西部

Control Degree of Channel Sand-body in Dense Well Patterns——By Taking the Western Sazhong Block of Sa'ertu Oilfield for Example

松辽盆地沉积了特色的大型浅水河控三角洲,河道砂体类型多样,分布特征不尽相同,井网控程度高低不一。利用萨尔图油田中区西部2266口井资料,综合考虑砂体成因与形态,将砂体分为拼合叠置辫状河道带砂体、迁移叠置曲流带砂体、交织条带状分流河道砂体、枝状分流河道砂体、单支分流河道砂体;定义控制率、准确率和综合控制指数来定量表征井网对河道砂体控制程度;分析了控制不同类型河道砂体所需的合理井距,在500m或更大井距条件下就可以控制拼合叠置辫状河道带砂体和迁移叠置曲流带砂体,枝状分流河道砂体与交织条带状分流河道砂则分别需要100m井距与57m井距条件来控制,而单支分流河道砂体需要更小井距才能得到有效控制,最终总结出了不同类型河道砂体的井网控制程度曲线,概括为三段式。

There deposited a large shallow fluvial delta in Songliao Basin,it had a variety of channel sand bodies with different distributive characteristics and different control degrees of well pattern.Based on the data of 2266 wells in Western Sazhong Block,the genetic mechanism and shape of the channel sand bodies were taken into consideration,the channel sand bodies were divided into channel sand bodies of splice overlaid braided river,migration overlaid meandering river,intertexture banding distributary channel,dendritic distributary channel and single distributary channel.The defined controlling rate,accuracy rate and integrating controlling index were used for quantitative characterization of the controlling degree of well pattern on different types of channel sand bodies.The reasonable well spacing controlling different types of channel sand bodies was analyzed.As a result,in the condition of 500m or more larger well spacing,the channel sand body of splice overlaid braided river and the migration overlaid meandering river can be controlled,while the intertexture banding distributary channel sand body and dendritic distributary channel sand bodies can be controlled in the condition of 100m and 57m well spacing.Similarly,the single distributary channel sand body needs less than 57m of controlling space.Finally the curve of controlling degree of well pattern for different types of channel sand bodies is summed up,which can be divided into three stages.