基于改进BPNN与T_2全谱的致密砂岩储层渗透率预测  

Permeability prediction of tight sandstone reservoir based on improved BPNN and T_2 full-spectrum

作　　者：朱林奇 张冲[1,2] 何小菊[3] 吴中彬 周新波[5] 袛淑华 李阳[6] 

机构地区：[1]长江大学油气资源与勘探技术教育部重点实验室,湖北武汉430100 [2]长江大学地球物理与石油资源学院,北武汉430100 [3]中国石油天然气集团公司测井有限公司长庆事业部,陕西高陵710201 [4]中国石油化工股份有限公司胜利油田有限公司桩西采油厂,山东东营257237 [5]中国石油天然气股份有限公司塔里木油田分公司天然气事业部,新疆库尔勒841000 [6]中国石油天然气集团公司测井有限公司华北事业部,河北任丘062552

出　　处：《石油物探》2017年第5期727-734,共8页Geophysical Prospecting For Petroleum

基　　金：湖北省自然科学基金项目(2013CFB396);中国石油天然气集团公司重大专项(2013E-38-09)共同资助~~

摘　　要：针对现有核磁共振测井渗透率模型对孔隙结构复杂的致密砂岩储层预测精度不高的问题,在分析误差反向传播神经网络的缺陷后,提出了一种利用集成正则化改进神经网络(BPNN)算法与核磁共振T_2全谱预测致密砂岩储层渗透率的方法。该方法采用自构形算法自动确定隐层神经元的个数,采用自适应雨林优化算法避免BP神经网络迭代陷入局部极小值,利用L_2正则化算子保证算法的稳定性,采用Adaboost集成算法串联若干BP神经网络以提高模型泛化能力。提取某区致密砂岩储层192块岩样的核磁共振T_2全谱数据进行建模,并应用于非建模井的渗透率评价,认为基于集成正则化改进BPNN算法评价储层渗透率精度较高,均方误差仅有0.286。In view of the difficulty of the existing NMR logging permeability model in the prediction of a tight sandstone reservoir with complex pore structures,after analyzing the defects of the back-propagation neural network （BPNN）,we propose a method for predicting the permeability of tight sandstone reservoirs by using the BPNN algorithm improved by integrated regularization and discrete NMR T2 full-spectrum data. For this method, a self-shaping algorithm is employed to automatically determine the number of hidden neurons, an a- daptive rairfforest optimization algorithm is used to avoid the BPNN iterations into local minimum values, the L2 regularization technique is used to guarantee the algorithm stability, and the AdaBoost algorithm is used to concatenate several BPNNs to improve the generalization ability of the model.Discrete NMR T2 full-spectrum data were extracted from 192 samples of tight sandstone reservoirs in a certain area for model building, which was used to predict the permeability of non-modeling wells.The results showed that it was more accurate to use the BPNN algorithm improved by integrated regularization in evaluating reservoir permeability,with a mean squared error of 0.286 only.

关 键 词：核磁共振测井 T2全谱 渗透率 集成算法 L2正则化 自适应雨林算法 集成正则化改进BPNN算法 

分 类 号：P631[天文地球—地质矿产勘探]