METHOD FOR EDGE OIL RIM DEVELOPMENT Russian patent published in 2012 - IPC E21B43/20 

FIELD: oil industry.

SUBSTANCE: the invention relates to oil industry. Output wells and injection wells are drilled. In order to prevent the dissolution of oil rim reserves and to activate the oil reserves, beginning from the zero-point effective oil height and to push oil towards the centre of the oil rim, pressure barriers are created at gas-oil contact (GOC) and water-oil contact (WOC) levels. The pressure barriers are created by installing barrier rows of horizontal injection wells with bore alignment parallel to GOC and WOC circuits near the GOC inner circuit and WOC outer circuit respectively; and by installing additional barrier rows of horizontal injection wells at GOC and WOC contact levels between the inner and outer GOC circuits and inner and outer WOC circuits respectively. One-row flooding patterns are organized within the boundaries of the oil rim, based on horizontal output wells and injection wells with horizontal bores drilled in check order and aligned in parallel to GOC and WOC. Horizontal output bores are positioned close to producing formation top in oil and water zones and with a shift down from GOC level in under-gas-cap zone. Injection bores are positioned at producing formation bottom. To extract the remaining oil reserves formed because of gravity near the top of formation, output wells that were out-of-operation because of water or gas invasion into the product are brought into service in 3-5 years. In case of abnormally low initial formation pressure water is pumped with the controlled level of overcompensated drainage by keeping the bottomhole pressure in injection wells larger by a given amount than the initial formation pressure, but below the hydrofracture pressure limit of the formation.

EFFECT: increased development efficiency of edge oil rims in oil-gas condensate field.

3 cl, 2 tbl, 5 dwg