海上薄互层砂岩油藏层系划分及射孔优化方法——以蓬莱19-3油田为例  

Stratification and Perforation Optimization Method for Offshore Thin Interbedded Sandstone Reservoir:A Case Study of PL19-3,Bohai

作　　者：康博韬 张迎春 姜彬 陈国宁 郜益华 李晨曦 KANG Bo-tao;ZHANG Ying-chun;JIANG Bin;CHEN Guo-ning;GAO Yi-hua;LI Chen-xi(State Key Laboratory of Offshore Oil Exploitation,Beijing 100028,China;CNOOC Research Institute Ltd.,Beijing 100028,China)

机构地区：[1]海洋石油高效开发国家重点实验室,北京100028 [2]中海油研究总院,北京100028

出　　处：《科学技术与工程》2021年第17期7067-7073,共7页Science Technology and Engineering

基　　金：国家科技重大专项(2011ZX05030-005)。

摘　　要：海上薄互层砂岩油藏小层层数多、厚度薄、展布范围有限,物性差异大,并且海上注采井距大,导致其层间干扰影响因素更为复杂,传统预测方法适用性差,层系划分及射孔优化难度大。针对海上薄互层砂岩油藏的储层发育特征,通过引入小层动态连通系数、小层流动能力系数、小层干扰系数等参数全面考虑不同井距条件下小层注采连通状况、小层物性、流体差异程度以及小层水淹程度等关键性因素;以蓬莱19-3油田为例,油藏工程和动态分析相结合建立了海上薄互砂岩油藏层间干扰规律定量预测方法;通过修正传统产能公式,建立了适用于海上薄互层砂岩油藏的定向井合采产能预测方法;研究方法在蓬莱19-3油田现场进行实例应用,预测精度高,实用性强,可有效指导新区开发井的层系划分及老区加密井的射孔优化等工作,应用效果理想。研究表明:海上薄互层砂岩油藏层间干扰主要受到小层注采连通状况、物性、流体以及水淹程度等因素的影响;建议将流动能力级差5.0作为海上薄互层砂岩油藏的层系划分标准,后期选择合理时机进行层系调整,减缓层间干扰。可见研究方法考虑因素全面,预测精度高,现场实用性强,能够为此类油田的新区开发井的层系划分及老区加密井射孔优化提供有力支持。Due to the large number of small layers,thin thickness,limited distribution range and large difference in physical properties of offshore thin interbedded sandstone reservoirs,as well as the large distance between offshore injection and production wells,the influencing factors of interbedded interference are more complex,the applicability of traditional prediction methods is poor,and it is difficult to divide layers and optimize perforations.Considering the reservoir characteristics of offshore thin interbedded sandstone reservoirs,the dynamic connectivity coefficient,flow capacity coefficient,interference coefficient were introduced to fully incorporate the key factors including injection-production connectivity,physical properties,fluid properties,and water flooded degree.Taking the PL19-3 as an example,a quantitative prediction method for the interlayer interference law had been established through the combination of reservoir engineering methods and production performance analysis.By modifying traditional methods,a prediction method for directional well's productivity at different water-cut stages for offshore thin interbedded sandstone reservoirs had been established.The method had been applied to PL19-3,and proved to have high prediction accuracy and applicability.The results show that interlayer interference in offshore thin interbedded sandstone reservoirs is mainly affected by injection-production connectivity,physical properties,fluid properties and water flooded degree.The flow capacity difference of 5.0 should be used as the criteria for the stratification in offshore thin interbedded sandstone reservoirs.It can be seen that the research method has comprehensive considerations,high prediction accuracy and strong field practicability,which can provide strong support for stratification of new development wells and perforation optimization of infill wells in old areas of this kind of oilfield.

关 键 词：薄互层 层间干扰 产能评价 层系划分 射孔优化 

分 类 号：TE331[石油与天然气工程—油气田开发工程] P618.13[天文地球—矿床学]