METHOD OF NEUTRON CEMENTOMETRY FOR DIAGNOSTICS OF FILLING OF ANNULAR SPACE OF OIL-AND-GAS WELLS WITH VERSIONS OF LIGHT CEMENT PASTE (VERSIONS) Russian patent published in 2019 - IPC E21B47/05 G01V5/10 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil and gas industry, in particular, to means of monitoring condition of cement stone behind casing of oil and gas wells and quality of cementing. In analyzed wells there performed is 2NNLt and 2NNLet, as a result of which intensity of epithermal neutron flux intensity is registered at small – J_nnl.et.sp and large – J_nnl.et.lp probes method 2NNLet and intensity of streams of thermal neutrons at small – J_nnl.t.sp and large – J_nnl.t.lp probes 2NNLt method, calculating cement functional F_cem=J_nnl.et.sp/J_nnl.et.lp × J_nnl.et.sp/J_nnl.t.sp, then along the palatine dependence F_cem.p from Cem obtained on models of formations, quantitative content of Cem cement in % is determined in accordance with coefficient of porosity C_p(GSW) determined by a set of geophysical survey of wells (GSW) of open hole of analyzed well or in accordance with coefficient of porosity C_p, obtained as a result of measurement by probes 2NNLt method: F(C_p)=J_nnl.t.sp/J_nnl.t.lp.

EFFECT: technical result consists in improvement of reliability of results of investigations of wells by neutron methods by opening analytical capabilities of a complex of neutron probes in modifications 2NNLet – double-probe neutron-neutron logging by epithermal neutrons and 2NNLt – double-probe neutron-neutron logging by thermal neutrons.

6 cl, 4 dwg