METHOD OF THE CUTTING WELL RESEARCH IN THE DRILLING PROCESS Russian patent published in 2019 - IPC E21B47/117 

FIELD: mining.

SUBSTANCE: invention relates to a method for investigating a well cut during drilling and can be used to quickly isolate reservoirs and determine their hydrodynamic parameters. Method of investigating the well section during drilling involves periodically stopping the deepening of the well, turning off the circulation of flushing fluid, moving the drilling tool with the piston well at different speeds of the first and second lifting and lowering tools. At that after the first lifting of the tool at the maximum speed, the well is filled with a flushing fluid from the measuring tank until it is completely filled and from the difference in measured volumes of the raised instrument and the flushing fluid to the well determine the amount of formation fluid entering the well, depending on which determine the mode of the well – depression or repression. Further well swabbing is performed depending on the established mode: either in the depression mode with the subsequent second lifting of the tool, after the corresponding descent at a lower speed, or in the repression mode with the well swabbing during the descent of the tool, with the first descent of the tool at a higher speed. After each descent of the instrument, the volume of absorbed washing fluid is determined from the difference between the measured volumes of the deflated tool and the flushing fluid displaced from the well, while the hydrodynamic parameters of the selected reservoir, in particular the reservoir pressure, is determined taking into account the established regime, with depression: P_d=((ω_n-υ_n2)t_n1P_n1-(ω_n-υ_n1)t_n2-P_n2)/((ω_n-υ_n2)t_n1-(ω_n-υ_n1)t_n2) (2), where P_d – reservoir pressure on depression; t_n1 and t_n2 – time, respectively, of the first and second lifting tool for depression; P_n1 and P_n2 – bottom hole pressure, respectively, during the first and second lifting of the tool for depression; υ_n1 and υ_n2 – the volume of the flushing fluid from the measuring tank into the well until it is completely filled, respectively, after the first and second lifting of the tool for depression; ω_n – the volume of the raised tool from the well when it is full; repression: P_p=((ω_c-υ_c2)t_c1P_c1-(ω_c-υ_c1)t_c2-P_c2)/((ω_c-υ_c2)t_c1-(ω_c-υ_c1)t_c2) (3), where P_p – reservoir pressure on repression; t_c1 and t_c2 – time, respectively, of the first and second descent of the instrument to repression; P_c1 and P_c2 – bottom hole pressure, respectively, during the first and second descent of the instrument for repression; υ_c1 and υ_c2 – the volume of fluid displaced from the well into the measuring capacity, respectively, after the first and second descent of the instrument for repression; ω_c – the volume of the deflated tool into the well when it is full.

EFFECT: technical result of the invention is to increase the reliability of the allocation and assessment of reservoirs.

1 cl, 4 dwg