Influence Correction Of Environmental Factors Of Russian Through Casing Resistivity Logging Data And Its Applications

As a new method of measuring formation resisitivity in cased holes, Through Casing Resistivity logging can get formation resistivity. After20years development, the logging instrument can reliably and accurately get the formation resistivity through the strict site logging test and a lot of logging operations. Though Casing Resistivity Logging shows the unique advantage in reservoir dynamic monitoring and Evaluation of remaining oil in oil filed. Geological application effect of Russian Through Casing Resistivity instrument introduced in2006has been approved after years of application in some oil filed. In recent years, many domestic organizations also have developed this kind of instrument.In the process of measurement, the influence of underground environmental factors on formation of interest can not be avoided. Environmental influences of the logging date come from casing, cement, surrounding rock, Instrument calibration coefficient (K factor):(1)Casing heterogeneity mainly reflects in casing collars. Most of resistance of casing collars increase, which make the logging data in the place of collars and nearby largely abnormal.(2)The influence of high-conductivity and thick cement can not be ignored.(3) Russian through Casing Resistivity logging instrument electrode is1.0m. the formation with that thickness is less than1.0m must determine thickness first by other logging data, and then do the calibration processing for surrounding rock.(4) K factor of Russian Through Casing Resistivity logging instrument is the function of unit length resistance and diameter of casing and formation resistivity. Formation resistivity before application need to be calibrated by choosing a stable impervious or mudstone formation.When these environmental factors influence the formation resistivity, the Logging data must be adjusted. Currently Russia Though Casing Logging instrument also lack of environmental correction methods to support the use of. This paper researches on the environmental correction of Russia Though Casing Resistivity logging.First of all, We make a large amount of numerical simulation for the environmental factors of Russia Through Casing Resistivity Logging instrument ECOS-31-7using the modified transmission lines, Then we analyses the casing collar, cement and surrounding walls, obtain a set of environmental correction charts of these major environmental impact. Next, Using C++language develop software to process the logging data of Through Casing Resistivity instrument. The software can be articulated in FORWARD2.7, realizes the function of automatically checking calibration charts. And Users can process interactively through the graphic interface and dialog, improve the efficiency of processing data. Finally we have processed environmental correction for more than10wells in Xing Jiang oil filed, achieved good application effect.