A Research Of Accurate And Subdivisional Relative Flow Rate Injection Profile Interpretation Method

Injectivity profile logging mainly include turbine flow rate logging, electromagnetic flow rate logging, isotope tracer logging, pulsed neutron oxygen activation logging, etc. Among them, the turbine flow rate logging and electromagnetic flow rate logging only adapting to commingled water injection well, cannot be used in the water injection well with complex strings. Isotope tracer logging can be used in water injection well with complex strings, but significantly affected by the radioactive contamination and " high capacity channel". Pulsed neutron oxygen activation logging can overcome above limitations of the water injection profile logging, but cost high, and the logging technology is complex. Changqing oilfield production layer generally has the characteristics of low porosity and low permeability reservoirs, the big difference between layers and most wells using regulating separate stratum injection, strings are complex, and injected water volume is low, conventional injection profile logging methods cannot satisfy the need inRelative flow rate logging is a new water injection profile logging method introduced in recent years, This method is to use down hole instrument release trace fluid(the tracer either burst or continuous release that they will be uniform and not settle down, not diffuse much, not contaminate tubing, casing or down hole tools in injection wells), trace fluid flow with the water within the well bore, the instrument equipped with gamma ray detector, that can continuous tracking measuring trace fluid velocity (i.e., the water within the well bore), thus the water flow rate of every water accepting layer can be calculated.This paper first through tracer flowmeter logging principle to analyze the relative flow rate logging principle, there are both some similarities also contains some of the differences, and then analysis the influence factors of relative flow rate logging method(including casing pipe diameter changes, fluid loss between probe and tracer release), and study the relative flow rate logging data interpretation methods (tracking method and area method), data processing program design, which mainly introduces the data processing and interpretation process and the function of each module, and finally summarized the application of relative flow rate logging.A large number of measured data show that relative flow rate logging can satisfy the need of Changqing oil field, this method can simultaneously measure the pipe flow and annular flow, and through annulus peaks to calculate annulus flowrate change to accurately and subdivisionally evaluate the injection water information of perforated interval. When measure the annulus peaks the lower limit is lower, the minimum can be measured to flow annulus2-3square, more suitable for low porosity and low permeability oilfield injection wells. And overcome the influence of such factors as deep penetration perforation, high capacity channel, contamination and leakage, the logging results are more reliable and intuitive, which provide the basis for oilfield in the late development.