In view of the situation that the spontaneous potential (SP) abnormality in some wells of Shengli Oilfield at high resistivity zones, such as Dongying group and membersⅠ,Ⅱ and Ⅲ of Shahejie group resulted in disunity of rock feature with wireline logging data and errors in interpretation, combining with on-site samples, the paper made analysis of SP abnormality of high resistivity pay zones.

Cased-well Formation Resistivity logging is one of the new well- logging methods which was proposed during the later 90\'s, because of its capability of measuring the formation resistivity in cased borehole, which is very different from the traditional open-hole well logging, it can be used in different stage in oil and gas development.

Study on logging response mechanism shows that,reservoir with high mud and irreducible water saturation,thin layer and interlayer are main causes for forming low-resistivity oil layer,while being tight and containing calcareous and residue oil are main factors of forming high-resistivity water layer.

There are many difficulties for judging reservoir and fluid properties because of the Feixianguan Ertan high resistivity zones in the north-east Sichuan.