| 摘要 |
The invention relates to oil producing industry and can be used for exploiting minor oil deposits (up to 10 mln tons).The proposed method provides conditions for preserving natural water-oil contact for the whole period of the oil deposit production due to maintaining strata pressure at the initial level and even higher.The method is realized at each local structure forming oil formation by drilling a vertical prospecting borehole in the oil structure dome later used as an injection borehole. The next step includes drilling a cluster of wells comprising an injection borehole and operation inclined wells with mouths spaced 10-20 meters from the injection borehole and borehole bottoms arranged along the structure inner perimeter, repeating its configuration striking oil stratum at 75-85°.The operation of all cluster boreholes is started simultaneously by pumping separating gases and/or casing head gas, natural gas from neighboring gas wells or inert gases into all productive oil strata provided maintaining pumping pressure P, being equal or higher pressure in the oil strata (P≥ P). Thus, a complete cycling process of oil production is reached, when the liquid oil phase is replaced by the pumped gas, after which the oil deposit is exploited producing gas mixture with subsequent transfer to gas condensate production and further to dry gas production.It is worth to mark that gas is pumped through the injection borehole into all production strata at negligible difference of pressure in the oil strata disposed at different depths. In case the pressure difference exceeds 5 atm., the gas is pumped and oil is produced using the “bottom-up” method, that is starting from the lowest stratum.Maintaining (P≥ P) provision and replacement oil (or oil condensate) by gas excludes premature deposit watering and guarantees the oil recovery factor at 0.9-0.95, fully preserving oil-well gas and gas in a gas cap. |
