METHOD OF DRILLING INTO WATER-ENCROACHED PRODUCTIVE BEDS Russian patent published in 2003 - IPC

FIELD: production of liquid hydrocarbons. SUBSTANCE: invention can be specifically used to drill into water-encroached productive beds by second shaft while restoring wells out of operation in oil fields at latest stages of their development. Method of drilling into water-encroached productive bed consists in drilling of second shaft through window in operating string of restored well which is terminated in horizontal section in productive bed. Salient feature of method consists in that inclined pilot bore is drilled through window in operating string of restored well, it crosses productive bed from roof to bottom, geophysical studies of bed are conducted in pilot bore, oil-saturated seam of productive bed is exposed, cement bridge insulating this seam from bottom of pilot bore to point of drilling of horizontal section of second shaft is installed and this section is drilled to oil-saturated seam in sector which direction is determined by azimuth of pilot bore. EFFECT: possibility to drill into water-encroached productive beds through oil-saturated seams and to recover water- free crude from oil fields at latest stages of development. 3 cl, 2 dwg