Reservoir characteristics and log identification of carbonate buried hill inner reservoirs in Nanpu Area

摘要

There are many inner reservoirs of the lower Paleozoic carbonate buried hill in Nanpu area. Using core and FMI data to identify the inner reservoirs accurately. Based on the systems analysis of reservoir characteristics to classify the reservoirs. And by optimizing sensitive log parameters and establishing recognited function to identify all kinds of reservoirs. The result shows that inner reservoirs featuring with low porosity and low permeability in Nanpu area. The reservoir shows fracture - porosity and other 4 kinds of reservoir permeability space type and 3 kinds of pore structure type. According to various parameters, the inner reservoirs are divided into 3 types: Ⅰ、Ⅱ and Ⅲ. There are 4 kinds of sensitive logging parameters for inner reservoirs, incluing density，RLLS，CNL-φAC and ∣1/RLLS－ 1/RLLD∣.The normalized weighted identification function is established by selected the 4 logging parameters. When the function value is more than 0.32,the stratum is inner reservoir. Verificated of the reserved data, the average accuracy of this method is 88%. And the accuracy of the type Ⅰ reservoir is the highest, followed by the type Ⅱ and the lowest type Ⅲ.