Correction Method of RPM C/O in Offshore Heavy Oil Reservoir

At present, the most advanced remaining oil saturation logging technologies are RPM RST RMT PNN PND in domestic and outside. But these have only been made some correction of porosity, lithology, borehole conditions, formation water salinity, oil density. So they are not suitable for application in the offshore heavy oil reservoirs of gravel pack. The writer has designed a volumetric model of considering gravel pack, casing size, wellhole liquid and so on. And some correction formulas are deduced with single factor and multiple factors by combining this volume model. While the author use these formulas to establish some theoretical charts. In the case of that the porosity is 0.3, the author analyzes the C/O value change rule with the same oil saturation in sandstone strata. When the gravel packing volume of 0.1, the C/O value decreases about 0.15. When casing diameter increases from 6inches to 7inches, the C/O value increases about 0.2. When the casing diameter is 6inches, make the clay content, gravel content, and calcium content for 0.1, the C/O value increases about 0.6. After making the gravel pack and other influencing factors correction, contrast RPM data interpretation results and PLT data interpretation results. It is found that the results of remaining oil explain accuracy is improved 10% or more. These methods provide a new theoretical basis for the offshore heavy oil reservoir in the fine interpretation of RPM data.