METHOD FOR NEUTRON-NEUTRON CEMENTOMETRY - NNK-C FOR QUALITY CONTROL OF CEMENTING WITH LIGHTWEIGHT AND REGULAR CEMENTS OF WELLS UNDER CONSTRUCTION AND THE STATE OF CEMENT STONE OF OPERATING OIL AND GAS WELLS FILLED WITH ANY TYPE OF TYPES Russian patent published in 2022 - IPC G01V5/10 

FIELD: cementing quality control.

SUBSTANCE: invention is intended to control the quality of cementing with lightweight and conventional cements of wells under construction and the state of the cement stone of operated oil and gas wells. The substance of the invention lies in the fact that the method for two-probe neutron-neutron logging (2NNK) is used to control the quality of cementing the annulus of wells under construction and to control the state of the cement stone of operated oil and gas wells filled with any type of fluids, while determining the functional - Si, characterizing the relative proximity normalized reverse neutron count rates of two NNK probes, which responds only to the degree of cement integrity and does not depend on lithology, porosity - Kp and oil and gas saturation - Kgs of the formation. This functional Si is calculated according to given formulas and allows you to determine the volume fraction of cement - CEMi in the annulus or the indicator of cement integrity according to the formula: CEMi=(1-Si) ⋅100%.

EFFECT: expanding the scope and increasing the information content of neutron-neutron cement logging (NNC-Ts) to determine the state of cement behind the production casing (PC).

5 cl, 8 dwg