利用碳氢比测井技术评价剩余油及水淹程度

碳氢比测井是以地层中的碳、氢元素为主要研究和探测对象，以碳氢比值求解含油饱和度，降低了孔隙度的影响且不受矿化度的限制。依据5种类型油藏，15口井的测井解释结论与试油结论、密闭取芯含油饱和度资料进行分析研究，验证碳氢比（R_CH）与孔隙度和含油饱和度的关系，R_CH受孔隙度影响比较小，主要受含油饱和度的控制，随含油饱和度的变化而变化；测井解释结论与取芯含油饱和度和试油结论资料的准确性、可靠性、一致性和相关性都较好。实例分析结果表明：该方法可有效评价油层水淹程度、含油饱和度和油水界面，为寻找遗漏油层和堵水等措施提供有效资料，在砂泥岩剖面中适用范围较广，无论是砂岩、砾岩以及低阻油藏均可取得显著的地质效果。

Evaluating Residual Oil Saturation and Water-flood Degree with Hydrocarbon Ratio Logging

R_CH logging technology focuses on carbon and hydrogen ratio in the stratum to get the oil saturation,which mitigates the effect of porosity and is free from the limitation of salinity. The authors analyzed and identified the relation between the R_CH and oil saturation according to the conclusions of the R_CH interpretation and oil testing of 15 wells of five reservoirs types, as well as the data on hermetic core oil saturation. the analysis revealed that the oil saturation, rather than porosity has the prominent effect on the R_CH, which changes along with oil saturation changes; The conclusions of the R_CH interpretation and oil testing are accurate,credible and of good correlation. The test on the five reservoirs types indicated that the R_CH can evaluate waterflood degrees and the residual oil saturation effectively. It can provide reliable data in searching missing oil reservoir and providing measures of water plugging as well. Besides, the R_CH can be widely-used in sand shale profile. It has a remarkably geological effect in sand, mud or low resistance oil reservoir.