METHOD TO DEVELOP OIL ACCUMULATION IN LAMINAR CARBONATE RESERVOIRS Russian patent published in 2010 - IPC E21B43/20 

FIELD: oil-and-gas industry.

SUBSTANCE: invention relates to development of oil accumulation by horizontally branched wells, in particular, of thin carbonate formations-reservoirs with depth making, at least, two meters each. Substance claim: Proposed method comprises arranging, drilling vertical branched fill-in well and branched vertical extraction well with horizontal bores, injecting displacement fluid through vertical fill-in wells and draining oil through branched horizontal extracting well. In compliance with this invention, at least, two thin carbonate formations-reservoirs are selected arranged in close proximity to each other and separated by clay bands. Propagation of oil-filled depth of reservoirs over the area of oil accumulation are determined, areas with maximum tolerable oil-filled depth of reservoirs making at least two meters each are selected. Now, branched horizontal well is drilled to simultaneously develop two and more formations-reservoirs, horizontal wellbores are arranged in most permeable intervals of formations. Note here that wellbores are directed along increase in oil-filled depth, while wellbore length is taken to be inversely proportional to its permeability.

EFFECT: higher efficiency, increased oil extraction, reduced costs.

1 ex, 2 dwg