METHOD OF HORIZONTAL METHANE COAL WELL DESIGN SELECTION Russian patent published in 2020 - IPC E21B47/00 E21B47/02 E21C39/00 

FIELD: soil or rock drilling; mining.

SUBSTANCE: invention relates to extraction of methane from coal beds and can be used in designing methane-coal deposit development schemes. Method involves preparation of a one-dimensional geomechanical model based on research data in a draining vertical well or in nearby vertical structural and exploration wells, consisting of plotting, by well depth, a graph of formation pressure P variation by hydrodynamic analysis results, constructing a curve of geostatic stress σ_v from results of density logging, plotting curves of horizontal stresses σ_h and σ_H from data of acoustic logging. Obtaining in the range of the target coal bed values of stress tensor components characterizing its natural stress-strain state prior to construction of the horizontal well. Construction of two-dimensional geomechanics models for various versions of the horizontal well design in planes perpendicular to the horizontal section axis, using the stress tensor components as boundary conditions, determined according to the prepared one-dimensional geomechanical model. Estimation of coal bed permeability change at different versions of horizontal well design and selection of the version causing the greatest increase of coal bed permeability.

EFFECT: technical result consists in improvement of accuracy of determining the most efficient for existing mining and geological conditions of the structure of a horizontal methane coal-bearing well without the need for additional borehole investigations.

1 cl, 6 dwg