# A New Algorithm Model Based on Extended Kalman Filter for Predicting Inter-Well Connectivity
## 6 Quantitative Classification of Ineffective Circulation Channels
### Application of Ineffective Circulation Channels  
Thanks to the dynamic advantages of the SV-DC model, the connectivity level can be determined in combination with the recommended formulas, Equation (6) and Equation (12), and the data of connectivity coefficient, distribution coefficient (calculated based on the well group as a whole, where the total connectivity within the group is considered as 1, and individual well connectivity is derived as a proportion of this total), and connectivity volume from the early, middle and late stages can be obtained. The early stage refers to 0-40 months, the middle stage refers to 40-80 months, and the late stage refers to the subsequent 80 months. The well pairs classified as Level I and Level II in Table 6 are those with a high probability of developing ineffective circulation channels. Table 7 also focuses on discussing these well pairs in detail. In each of these stages, the inter-well connectivity coefficient, inter-well connected volume, and time-lag coefficient may vary \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Well Group** & **Development** & **Development** & **Well Group** & **Production Well** & **Development** & **Development** \\
**Name** & **Methodian Time** & **Level** & **Name** & **Methodian Time** & **Level** \\ \hline \multirow{6}{*}{QHD32-6-C03} & QHD32-6-H19H1 & / & IV & & QHD32-6-C11 & August 2015 & II \\ \cline{2-6}  & QHD32-6-H21H & / & IV & & QHD32-6-H43H & / & IV \\ \cline{2-6}  & QHD32-6-H3H & June 2017 & I & & QHD32-6-29H & / & IV \\ \cline{2-6}  & QHD32-6-B26 HS & May 2018 & II & & QHD32-6-C17 & & IV \\ \cline{2-6}  & QHD32-6-C02 & / & IV & & QHD32-6-C24 & / & III \\ \hline \multirow{6}{*}{QHD32-6-C01} & QHD32-6-C01 & / & IV & & QHD32-6-H14H & September 2017 & II \\ \cline{2-6}  & QHD32-6-D28H & / & IV & & QHD32-6-D19H & / & IV \\ \cline{2-6}  & QHD32-6-H1H2 & / & III & & QHD32-6-H14H & April 2019 & I \\ \cline{2-6}  & QHD32-6-H4H & / & IV & & QHD32-6-H43H & / & IV \\ \hline \multirow{6}{*}{QHD32-6-C05} & QHD32-6-H22H & / & IV & & QHD32-6-H26H & / & IV \\ \cline{2-6}  & QHD32-6-H1H2 & September 2018 & II & & QHD32-6-H14H & July 2015 & II \\ \cline{2-6}  & QHD32-6-H4H & May 2018 & II & & QHD32-6-H21 & October 2016 & I \\ \cline{2-6}  & QHD32-6-I21H1 & / & IV & & QHD32-6-H12H2 & / & IV \\ \hline \multirow{6}{*}{QHD32-6-H19H1} & QHD32-6-H19H1 & / & III & & QHD32-6-H9H & January 2015 & II \\ \cline{2-6}  & QHD32-6-C2 & / & IV & QHD32-6-C22 & QHD32-6-H8H1 & / & IV \\ \cline{2-6}  & QHD32-6-H22H & July 2021 & II & & QHD32-6-H26H & / & III \\ \cline{2-6}  & QHD32-6-I39H1 & June 2021 & II & & QHD32-6-H21H & March 2015 & II \\ \cline{2-6}  & QHD32-6-I21H1 & March 2019 & II & & QHD32-6-C25 & & QHD32-6-I22H & / & IV \\ \hline \multirow{6}{*}{QHD32-6-C07} & QHD32-6-H19H1 & January 2022 & II & & QHD32-6-C23 & / & IV \\ \cline{2-6}  & QHD32-6-H19H1 & / & IV & & QHD32-6-H11H & August 2018 & I \\ \cline{2-6}  & QHD32-6-H21H & January 2022 & I & & QHD32-6-H12H2 & / & IV \\ \cline{2-6}  & QHD32-6-D12H1 & / & III & & QHD32-6-C23 & / & III \\ \cline{2-6}  & QHD32-6-H6H & November 2022 & I & & QHD32-6-H17H & January 2017 & II \\ \cline{2-6}  & QHD32-6-H21H & / & IV & & QHD32-6-H9H & November 2016 & II \\ \hline \multirow{6}{*}{QHD32-6-C09} & QHD32-6-H15H1 & June 2022 & II & & QHD32-6-H9H & / & IV \\ \cline{2-6}  & QHD32-6-H1H2 & / & IV & QHD32-6-C27 & QHD32-6-H8H1 & November 2022 & I \\ \cline{2-6}  & QHD32-6-H25H & / & IV & & QHD32-6-H10H1 & / & IV \\ \hline \multirow{6}{*}{QHD32-6-C10} & QHD32-6-D21H1 & / & IV & & QHD32-6-C28 & QHD32-6-H26H & December 2021 & I \\ \cline{2-6}  & QHD32-6-H1H2 & / & IV & & QHD32-6-43H & / & IV \\ \cline{1-1} \cline{2-6}  & QHD32-6-H25H & November 2022 & II & & QHD32-6-C29 & QHD32-6-C2 & / & IV \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Identification of ineffective channels in block Nm13, Qinhuangdao 32-6 Oilfield. significantly. Notably, in some cases, the inter-well connectivity coefficient may exceed 1, which is generally due to the production rate being greater than the injection rate.