METHOD FOR OIL FIELD DEVELOPMENT BY HORIZONTAL WELLS Russian patent published in 2006 - IPC E21B43/20 

FIELD: oil production industry, particularly for oil field development.

SUBSTANCE: method involves drilling inclined main transport hole through formation towards water-oil contact level; drilling ascending additional branch holes; ascending branch hole bottom marks are drilled so that bottom marks thereof descend to main transport hole end. Bottom mark of the last ascending additional branch hole is set taking into consideration distance ratio defined by distance between vertical distance from lower point of main transport horizontal hole, which is head mark of the last ascending branch hole, to water-oil contact level and distance from bottom of the last ascending additional branch hole to water-oil contact level. Above distance ratio is to be equal to 0.3-0.5. Bottom mark of the first ascending additional branch hole is set from distance ratio defined by vertical distance from head of the first ascending additional branch hole to water-oil contact level and distance between bottom of the first ascending additional branch hole to water-oil contact level, wherein above distance ratio is to be equal to 0.6-0.8. Bottom marks of intermediate ascending additional branch holes arranged between the first and the last ones are set from distance ratio defined by vertical distance from head of corresponding ascending additional branch hole to water-oil contact level and distance from bottom of the same ascending additional branch hole to water-oil contact level, wherein the distance ratio is to be equal to 0.3-0.8. The main transport horizontal hole is provided with flow string arranged so that flow string bottom is located in lower point of main transport horizontal hole. Oil is produced through ascending additional branch holes.

EFFECT: increased oil recovery from the field.

1 ex, 1 dwg