Oil recovery method and apparatus

The method of forming a substantially fluid-impervious screen in a subterranean hydrocarbon deposit comprising the steps of

• (a) forming a plurality of boreholes extending from the earth surface into said subterranean deposit along the desired vertical plane of said screen;
• (b) injecting a fluid medium into a plurality of said boreholes simultaneously in a series of pressure pulses under sufficient pressure to fracture the region of said deposit between said boreholes, thereby forming a substantially vertical zone of fractured deposit extending along said desired vertical plane;
• and
• (c) injecting a sealing medium into said vertical zone of fractured deposit which solidifies to form a substantially fluid-impervious barrier.

A system for removing liquifiable hydrocarbons from a fluid-permeable subterranean deposit thereof comprising

• (a) substantially fluid-impervious vertical barrier means defining an enclosed fluid-permeable subterranean deposit of liquifiable hydrocarbons;
• (b) first means for injecting a substantially liquid medium into said enclosed subterranean deposit;
• (c) means for injecting a fluid medium into said first means in a series of pressure pulses;
• (d) second means for withdrawing fluid containing said liquid medium from said subterranean deposit, said first means being spatially removed from said second means whereby fluid injected through said first means must horizontally traverse a substantial portion of said enclosed subterranean deposit to be withdrawn from said second means;
• and
• (e) means for separating hydrocarbons from said liquid medium withdrawn from said second means and recirculating said liquid medium through said enclosed subterranean deposit.

The method of recovering liquifiable hydrocarbons from a fluid-permeable subterranean zone containing entrapped deposits thereof comprising the steps of:

• (a) forming a substantially fluid-impervious vertically extending screen to isolate said fluid-permeable subterranean zone from other fluid-permeable subterranean zones by
• (i) forming a plurality of boreholes extending from the earth surface into said fluid-permeable subterranean zone substantially aligned along the desired vertical plane of said screen;
• (ii) fracturing the subterranean zone between said boreholes;
• and
• (iii) sealing the fractured zone by injecting sealing medium into said fractured zone;
• (b) forming a plurality of injection wells for injecting a fluid medium into the isolated subterranean zone;
• (c) forming a plurality of production wells for withdrawing fluid from said isolated subterranean zone, said production wells being horizontally removed from said injection wells;
• and
• (d) alternately injecting a fluid medium into said production wells and said injection wells in a series of pressure pulses and simultaneously continuously withdrawing fluid from said production wells.

Apparatus for removing liquifiable hydrocarbons from a fluid-permeable subterranean deposit thereof comprising:

• (a) substantially vertical and substantially fluid-impervious barrier screen means isolating said subterranean deposit from other fluid-permeable earth formations;
• (b) at least one injection well for injecting a fluid medium into the isolated subterranean deposit;
• (c) at least one production well for withdrawing fluid from said isolated subterranean deposit, said production well including an injection tube for injecting fluid medium into said isolated subterranean deposit and a production tube for simultaneously withdrawing fluid from said subterranean deposit;
• and
• (d) means for injecting a fluid medium into said injection well with sufficient pressure to cause said fluid medium to flow turbulently through the pore formations in said isolated subterranean deposit;
• wherein said means for injecting a fluid medium into said injection well comprises a pump, a distribution valve and a storage tank with said pump adapted to withdraw fluid from said storage tank and supply fluid under pressure to said distribution valve and said distribution valve is adapted to alternately direct said fluid under pressure into said injection tube in said production well while venting said injection well to said storage tank and direct said fluid under pressure into said injection well while venting said injection tube in said production well to said storage tank;
• thereby alternately supplying fluid under pressure to said injection well and said production well.