METHOD OF DRILLING WELLS AND DEVELOPMENT OF MULTIBED DEPOSITS OF HYDROCARBONS WITH NON-UNIFORM GEOLOGICAL CONDITIONS OF BED ATTITUDES Russian patent published in 2009 - IPC E21B43/14 

FIELD: oil and gas production.

SUBSTANCE: method consists in following: at first stage wells are drilled by two-stage cluster method into lower bed of high permeability chosen as main object of development; by-pass wells are drilled at each cluster into bed of low permeability with abnormally high bed pressure located over above said bed; structure of by-pass wells includes side wells with horizontal ends into both beds; pressure controlled overflow of fluid is performed via horizontal ends from upper high pressure bed into lower low pressure bed into zone of fluid spread limited with its contact with water with closed at wellhead wells; cement bridge as drilled impermeable parting is installed in main borehole above upper bed and between intervals of kick-offs of side boreholes; at second stage, when bed pressure in interval of exposing of upper high pressure bed drops to value exceeding hydrostatic pressure for not more, than 5-10 %, each cluster of producing wells is drilled; further deposit is operated with clusters producing fluid from lower bed. According to the invention the by-pass wells are drilled to high-permeable lower bed with preliminary overlaying the upper bed with a cased column; the side boreholes are drilled with horizontal ends into a lower bed from the main borehole; drilling fluid is replaced from the side boreholes and the main borehole by activated stream from the lower bed; the side boreholes with horizontal ends are drilled into the upper bed; drilling agent is replaced from the side boreholes and main borehole by activated stream from the upper bed. Also installation and drilling of impermeable parting is performed with the pressure tight well head and at depression.

EFFECT: reduced capital expenditure for drilling and efficient development of resources of both operational objects.

1 ex, 2 dwg