A new fast neutron gamma ray logging method for porosity and gas saturation calculation in cased hole is proposed. Based on the theory of recorded inelastic gamma ray is an integrated effect from formation density and fast neutron cross section, the inelastic gamma ray counts of different source spacing are simplified. And then, the formation porosity and gas saturation are calculated according to the rock physic volume model. The simulation results shown that the new method is less effect by water salinity. The new logging method is applied in gas reservoir, porosity and gas saturation is calculated in different depth, which is very benefit for gas exploitation.


Article metrics loading...

Loading full text...

Full text loading...


  1. Rosen, R. L., & Scott, H. D.
    [1989]. A gas saturation calculation based on neutron log count-rate ratio and formation neutron moderation properties. In SPWLA 30th Annual Logging Symposium. Society of Petrophysicists and Well-Log Analysts.
    [Google Scholar]
  2. Wichmann, P. A., & Youmans, A. H.
    [1967]. Advances in neutron lifetime logging. Journal of Petroleum Technology, 19(04), 479–486.
    [Google Scholar]
  3. Inanc, F., Gilchrist, W. A., Ansari, R., & Chace, D.
    [2014]. Physical Basis for a Cased-Well Quantitative Gas-Saturation Analysis Method. Petrophysics, 55(06), 598–617.
    [Google Scholar]
  4. Zhou, T., Rose, D., Quinlan, T., Thornton, J., Saldungaray, P., Gerges, N. & Lukman, A.
    [2016]. Fast neutron cross-section measurement physics and applications. In SPWLA 57th Annual Logging Symposium. Society of Petrophysicists and Well-Log Analysts.
    [Google Scholar]

Data & Media loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error