Application of Four Neutron Logging in Formation Evaluation

In the middle and late stages of oilfield development, after various measurements, especially in low porosity and low salinity reservoirs, it is more difficult to evaluate oil and water layers, and the existing logging methods can not meet the production needs. In order to solve the above problems, four-neutron logging is introduced. The technology uses AmBe neutron source to collect the information of neutron-neutron and neutron-gamma dual physical processes through four detectors, which reduces the dependence on open hole information. The mud content is calculated by using activated aluminium element. When calculating porosity and identificating fluid, the method of dual physical process measurement is used. So the influence of the borehole environment and fluid properties are eliminated. It can also magnify the fluid response information, so as to accurately evaluate the physical properties and remaining oil distribution after casing. And in the meantime, it is sensitive to the gas-bearing response of reservoirs. Field application proves that the four neutron logging is effective in formation evaluation.