Helicoid perforation
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The technology provides for the intensification of oil production with active plantar waters or in the presence of gas caps
Cheaper in 3-4 times than existing technology of hydraulic fracturing formation and applicable to complex geological conditions
Increasing the flow rate of oil wells, wellhead pressure reduction for injection wells.
Helicoid perforation is carried out by moving hydraulic perforator along the borehole axis and simultaneously rotating it around its own axis to form perforations, the movement speed and rotation perforator is selected based on the condition that the resulting perforation is helicoid to form a cavity in the treated formation. The step of the obtained helix is 10 cm., wherein the helix pitch is 0.7 maximum gap height. Perforations are combined with one another in the formation, due to the small step helix and is formed in a cylindrical annulus excavation radius greater than 0.5 m. The area of liquid filtration from the formation into the well 5 times higher than that of the open hole, which leads to a reduction skin factor to the level of hydraulic fracturing formation without breaking of roof or bottom formation or jumpers within the formation.
17-Jul-2015
2014130917
PCT/RU2015/000460
The invention belongs to the oil industry and can be used for enhanced oil recovery by formations’ yielding to the fullest extent possible under complicated mining and geological conditions. The method of repeated completion of the production formations by helicoid perforation includes perforation, which is performed by moving the perforator along well axis and simultaneously rotating it around its axis with making perforation channels, provided that the speeds of movement and rotation of the perforator are selected based on the condition that the perforation obtained as a result is a helicoid with creation an empty space in the processed formation, wherein hydraulic perforating cap (hydraulic perforator) is used as perforator and the pitch of the obtained helicoid is 10 cm, besides helicoid pitch is 0.7 of the maximum slot height.
The perforation channels are joined with each other in the formation due to small helicoid pitch and in casing string annulus a cylindrical mine working with radius over 0.5 m is created. The area of fluid filtration from the formation to the well is 5 times more than for open well bore, which leads to decreasing skin factor to the level of hydraulic fracturing of formation without destroying formation top and bottom or bridging inside the formation. The invention allows creating well open bottom-hole (cavity) of radius over 0.5 m and decreasing filtration resistances, decreasing risk of “shutdown” during hydraulic fracturing of formation and increasing filtration efficiency. 1 dependent claim, 2 illustrations.
2576269
俄罗斯
