METHOD FOR DETECTION OF INTERVALS OF INFLOW AND ABSORPTION OF FLUIDS IN OPERATING OIL-GAS WELLS Russian patent published in 2023 - IPC E21B47/10 G01V1/50 

FIELD: geophysics.

SUBSTANCE: invention relates to field-geophysical studies, namely, to methods for detection of intervals of inflow and absorption of fluids in a wellbore. In accordance with the proposed method for detection of intervals of inflow and absorption of fluids in operating oil-gas wells, noise is recorded along a wellbore by means of a noise measuring device placed in a well, and, at the same time, field-geophysical measurements are carried out. Field-geophysical studies contain thermometry, barometry, and mechanical flowmetry. A position of the noise measuring device in a cross-section of the wellbore is controlled. Analysis and processing of recorded noise in a time domain are carried out, during which clipped parts of a signal, as well as sharp high-amplitude emissions on waveforms, are identified and removed. The intensity distribution of recorded noise along the wellbore is calculated in two frequency ranges, and depths are identified, where there are sharp changes in trends of intensity profiles of recorded noise in selected frequency ranges and profiles of other field-geophysical measurements along the wellbore. Based on identified depths of a sharp change in profile trends, regression profiles are built for all measurements along the wellbore, and automatic marking of depth intervals along the wellbore is performed, where significant changes take place in each analyzed regression profile. Depth intervals along the wellbore are identified as candidates for the presence of inflow and absorption of fluids, where there is an intersection of markings of depth intervals of at least one field-geophysical measurement and distribution of noise intensity in at least one frequency range. A set of characteristic noise parameters in frequency and time domains is selected, and profiles of characteristic noise parameters along a well length are built. Depth intervals of noise occurrence are automatically split into several groups based on the selected set of characteristic noise parameters, and the nature of noise in obtained groups of depth intervals is identified. Intervals of inflow and absorption of fluids are identified by clarifying identified depth intervals along the wellbore as candidates for the presence of inflow and absorption of fluids based on the identified nature of noise in each group.

EFFECT: increase in the accuracy and reliability of determination of intervals of inflow and absorption of fluids in a well, as well as reduction in time required for interpretation of data of field-geophysical studies.

7 cl, 9 dwg