Abstract: A system is provided for injecting an injection fluid into an earth formation via a wellbore formed in the earth formation and for producing hydrocarbon fluid from the earth formation via the wellbore. The system comprises an injection conduit extending into the wellbore and being in fluid communication with a plurality of outlet ports for injection fluid, and a production conduit extending into the wellbore and being in fluid communication with at least one inlet section for hydrocarbon fluid. The injection conduit is arranged to prevent fluid communication between the injection conduit and each said inlet section.

Abstract: A method and apparatus of separating, in a production well, water from a water- and hydrocarbon-containing production flow emanating from at least one surrounding production formation; and also of injecting, in the production well, a resulting water-containing liquid into at least one surrounding disposal formation, whilst a resulting hydrocarbon-containing liquid is produced out of the production well. The water-containing liquid is separated from the production flow by using at least one water separation device being exposed to a pressure difference (P1-P2) that sucks water from the production flow and through the water separation device. Said water-containing liquid is thus provided. The water separation device may, for example, comprise at least one hydrophilic and water-permeable material. The pressure difference (P1-P2) may be provided through suitable adjustment of a gas pressure (P3) in a first gas column at a downstream side of the water separation device.

Abstract: A modified method for in situ recovery of hydrocarbon from an underground hydrocarbon-containing formation. An “L” shaped production well, having a vertical section, and a lower horizontal leg positioned low in the formation, is provided. The horizontal leg connects to the vertical section at a heel portion, and has a toe portion at an opposite end thereof. Oxidizing gas is injected into the formation in or proximate the vertical section. A combustion front sweeps outwardly from the vertical section and laterally within the formation above the horizontal leg, from the heel to the toe, causing hydrocarbons in the formation above the horizontal leg to drain downwardly into the horizontal leg, which are then delivered to surface via production tubing. A non-oxidizing gas is injected into at least the heel portion and preferably additional portions of the horizontal leg via injection tubing contained within the vertical section of the production well.

Abstract: A method is provided for in-situ production of oil shale, gas via gas (methane) hydrates and gas shale, and steam via geothermal formations wherein a network of fractures is formed by injecting liquified gases into at least one substantially horizontally disposed fracturing borehole. Thereafter, heat can be applied to liquify the kerogen or to dissociate the gas (methane) hydrates so that oil shale oil and/or gases can be recovered from the fractured formations.

Abstract: The present invention relates to subterranean treatment fluids, and more particularly, the present invention relates to subterranean treatment fluids comprising relative permeability modifiers and methods for using such subterranean treatment fluids in subterranean operations to reduce the production of water from and stimulate hydrocarbon production in a subterranean formation. In certain embodiments, the methods of the present invention generally comprise the steps of providing a permeability-modifying aqueous treatment fluid comprising a relative permeability modifier and contacting a subterranean formation with the permeability-modifying aqueous treatment fluid. Optionally, the permeability-modifying aqueous treatment fluid may be injected in the subterranean formation at a pressure sufficient to create or enhance at least one fracture therein. In another embodiment, the methods of the present invention further comprise the step of injecting an acidizing treatment into the subterranean formation.

Abstract: The present invention relates to well bore stabilization and, more particularly, to treatment fluids that may reduce the tendency of shales to swell and associated methods. In some embodiments, the present invention provides a method of stabilizing a subterranean formation that comprises a shale, the method comprising contacting the subterranean formation that comprises the shale with a treatment fluid, the treatment fluid comprising a base fluid, and a hydrophobically modified polymer. In other embodiments, the treatment fluids comprise a base fluid and a hydrophilically modified polymer. In yet other embodiments, the present invention provides shale-inhibiting components, treatment fluids, and methods of reducing the tendency of shale to swell when exposed to a treatment fluid.

Abstract: A technique enables injection of treatment chemicals at a plurality of desired locations along a well. A multi-point chemical injection system is connected and deployed into a wellbore. The multi-point chemical injection system delivers one or more treatment chemicals along the wellbore to the desired locations at a plurality of injection zones. A single control line is run from a surface location down through the wellbore to the plurality of injection zones. The single control line is used to deliver the treatment chemical to each of the injection zones.

Abstract: A method of top-filling a drill pipe string comprises injecting fluid into the upper end of the string. Apparatus for use in top-filling a drill pipe string comprises an injector adapted to co-operate with the upper end of a drill pipe string, whereby fluid may be pumped through the injector and into the string.

Abstract: A method of lowering the temperature of a subsurface formation, e.g., a subsurface formation including oil shale, includes completing a well having fluid communication with the subsurface formation at a first depth and a second lower depth. A fracturing fluid is injected into the well so as to form a fracture at a depth of the subsurface formation, and thereby provides fluid communication between the first and second depths in the well. A cooling fluid is circulated under pressure through the well and into the fracture so as to cause the cooling fluid to flow from the well, into subsurface formation at the first depth, to the subsurface formation at the second depth, and back into the well, thereby lowering the temperature of the subsurface formation.

Abstract: An electrical submersible pump (ESP) completion installed in casing perforated for water disposal and production. A packer separates the disposal zone and the production zone. An inverted ESP assembly is located inside of a canister. The ESP and canister are lowered on a tubing string into the casing. The canister has a downwardly extending canister extension flow-directing member that communicates with water in the casing and which passes through the disposal zone. Water is pumped down the canister extension member into the disposal zone and formation. Well fluids are drawn up the extension from the production zone. Various configurations are disclosed to facilitate flowing well fluids, e.g., oil-rich mixture or water passed the motor for cooling the motor of the inverted ESP while maintaining fluid segregation. The completion is particularly suited for production wells wherein the oil and water have a strong tendency to naturally segregate within the wellbore.

Abstract: A method, system and apparatus associated with the production of hydrocarbons are described. One apparatus includes a swellable packer element around a primary and a secondary flow path, wherein the packer is configured to block flow in a portion of a wellbore annulus. One method includes disposing sand control devices having shunt tubes and a packer within a wellbore adjacent to a subsurface reservoir. The packer is then set within an interval, which may be an open-hole section of the wellbore. With the packer set, gravel packing of the sand control devices in different intervals may be performed. Then, hydrocarbons are produced from the wellbore by passing hydrocarbons through the sand control devices with the different intervals providing zonal isolation. In some embodiments, intervals may be alternatively packed and plugged, wherein the plugged intervals are not packed. In addition, the method may also include disposing the sand control devices and packer into the wellbore in conditioned drilling fluid.

Abstract: Systems and methods for multi-lateral wellbore construction and stimulation from cased parent wellbores. Methods and apparatus are provided to facilitate the creation of casing exit openings in the casing of parent wellbores. Methods and systems are provided for azimuthally and longitudinally aligning drilling assemblies through openings in a parent wellbore casing are provided to allow for drilling multiple lateral wellbores extending outwardly from a parent wellbore. A method of stimulating one or more subterranean zones intersected by multiple lateral wellbores extending outwardly from one or more patent wellbores includes the steps of: simultaneously injecting a stimulation fluid into the lateral wellbores; and stimulating the zones intersected by the lateral wellbores in response to the stimulation fluid injecting step.

Abstract: The invention provides a method of treating a subterranean formation penetrated by a wellbore, the method comprising the steps of: (a) mixing a particulate and an active material to obtain an at least partially coated particulate, wherein: (i) water forms a contact angle of less than 90 degrees with a surface of the particulate, (ii) the active material is capable of forming a coating on the particulate, (iii) the active material forms a contact angle less than 90 degrees with the particulate, and (iv) water forms a contact angle of greater than 90 degrees with a layer of the active material; (b) mixing the at least partially coated particulate and a carrier fluid to obtain a treatment fluid; and (c) introducing the treatment fluid into the subterranean formation through the wellbore to deposit the at least partially coated particulate into the subterranean formation.

Abstract: The present invention relates to subterranean treatment fluids, and more particularly, the present invention relates to subterranean treatment fluids comprising relative permeability modifiers and methods for using such subterranean treatment fluids in subterranean operations to reduce the production of water from and stimulate hydrocarbon production in a subterranean formation. In certain embodiments, the methods of the present invention generally comprise the steps of providing a permeability-modifying aqueous treatment fluid comprising a relative permeability modifier and contacting a subterranean formation with the permeability-modifying aqueous treatment fluid. Optionally, the permeability-modifying aqueous treatment fluid may be injected in the subterranean formation at a pressure sufficient to create or enhance at least one fracture therein. In another embodiment, the relative permeability modifier may be provided by appropriate reaction in situ.

Abstract: The present invention relates to subterranean treatment fluids, and more particularly, the present invention relates to subterranean treatment fluids comprising relative permeability modifiers and methods for using such subterranean treatment fluids in subterranean operations to reduce the production of water from and stimulate hydrocarbon production in a subterranean formation. In certain embodiments, the methods of the present invention generally comprise the steps of providing a permeability-modifying aqueous treatment fluid comprising a relative permeability modifier and contacting a subterranean formation with the permeability-modifying aqueous treatment fluid. Optionally, the permeability-modifying aqueous treatment fluid may be injected in the subterranean formation at a pressure sufficient to create or enhance at least one fracture therein. In another embodiment, the relative permeability modifier may be provided by appropriate reaction in situ.

Abstract: A novel method is provided for in situ combustion and recovery of oil from underground reservoirs including injecting air into the reservoir at a region near the reservoir floor, withdrawing combustion products from a region near the reservoir ceiling, and collecting oil from a horizontal production well near the reservoir floor.

Abstract: An exemplary method of the present invention for performing an injection operation includes providing a water-soluble relative permeability modifier, introducing the water-soluble relative permeability modifier into a subterranean formation; and injecting an aqueous injection fluid into the subterranean formation after introducing the water-soluble relative permeability modifier. An exemplary permeability-modifying injection fluid of the present invention contains water-soluble relative permeability modifier. The water-soluble relative permeability modifiers of the present invention include hydrophobically modified water-soluble polymers, hydrophilically modified water-soluble polymers, and water-soluble polymers without hydrophobic or hydrophilic modification.

Abstract: An electrical submersible pump (ESP) completion installed in casing perforated for water disposal and production. A packer separates the disposal zone and the production zone. An inverted ESP assembly is located inside of a canister. The ESP and canister are lowered on a tubing string into the casing. The canister has a downwardly extending canister extension flow-directing member that communicates with water in the casing and which passes through the disposal zone. Water is pumped down the canister extension member into the disposal zone and formation. Well fluids are drawn up the extension from the production zone. Various configurations are disclosed to facilitate flowing well fluids, e.g., oil-rich mixture or water, past the motor for cooling the motor of the inverted ESP while maintaining fluid segregation. The completion is particularly suited for production wells wherein the oil and water have a strong tendency to naturally segregate within the wellbore.

Abstract: An injection pipe string (4) in a well (2) for the injection of a fluid into at least one reservoir (6) intersected by the string (4), in which at least parts of the injection string (4) opposite the at least one reservoir (6) are provided with one or more outflow positions/-zones. At least one pressure-loss-promoting flow control device is provided to each outflow position/-zone. In position of use, the flow control device(s) control(s) the outflow rate of the injection fluid to a reservoir rock opposite said position/zone. The flow control device(s) is (are) disposed between an internal flow space (18) of the injection string (4) and the reservoir rock opposite said position/zone, and said device(s) is (are) hydraulically connected to at least one through-going pipe wall opening (28, 86) in the injection string (4), and to said reservoir rock. By using such flow control devices, the outflow profile of the injection fluid may be appropriately controlled along the injection string (4).

Abstract: This invention relates to the field of treating subterranean formations to increase production. The method of the current invention is particularly useful in hydrocarbon wells that are long, for example, in excess of one kilometer. The method providing increasing production from a primary wellbore by intersecting this wellbore with a secondary wellbore near to the hydrocarbon production zone such that acid treatment or other treatment can be directed to the intersection.

Abstract: A method to clean a wellbore and the near wellbore area adjacent to the wellbore of a hydrocarbon bearing and/or coal bed methane formation adjacent to the production zone of the wellbore is provided. Specifically, a method for removing liquids such as water and/or oil from the near wellbore formation is provided. Furthermore, A method to clean a casing inserted into a wellbore is also disclosed. A method for cleaning a wellbore of fracturing fluid, with or without proppant is also disclosed. Each of the methods includes the steps of injecting either liquid carbon dioxide or a treatment medium comprising liquid carbon dioxide into a wellbore through tubing such that the location at which the treatment medium is administered may be controlled. In some embodiments, pressure within the wellbore is regulated in order to either maintain the treatment medium in the liquid state, or allow at least a portion of the treatment medium to vaporize upon introduction into the wellbore.

Abstract: The present invention involves a method and apparatus for enhanced recovery of petroleum fluids from the subsurface by convective heating of the oil sand formation and the heavy oil and bitumen in situ by a downhole electric heater. Multiple propped vertical hydraulic fractures are constructed from the well bore into the oil sand formation and filled with a diluent. The heater and downhole pump force thermal convective flow of the heated diluent to flow upward and outward into the propped fractures and circulating back down and back towards the well bore heating the oil sands and in situ bitumen on the vertical faces of the propped fractures. The diluent now mixed with produced products from the oil sand re-enters the bottom of the well bore and passes over the heater element and is reheated to continue to flow in the convective cell. Thus the heating and diluting of the in place bitumen occurs predominantly circumferentially, i.e.

Abstract: A method and apparatus for producing gas from a hydrate formation includes the use of at least one wellbore which penetrates the hydrate formation and further extends into an aquifer below the hydrate formation. The aquifer provides relatively warm water which may be produced up and into the hydrate formation thereby causing the release of gas from the hydrate. Suitable flow control and monitoring equipment may be included to control the flow of water produced from the aquifer and gas produced from the hydrate formation.

Abstract: A tubing string assembly is disclosed for fluid treatment of a wellbore. The tubing string can be used for staged wellbore fluid treatment where a selected segment of the wellbore is treated, while other segments are sealed off. The tubing string can also be used where a ported tubing string is required to be run in in a pressure tight condition and later is needed to be in an open-port condition.

Abstract: This invention is method of recovering gas from a gas-bearing subterranean formation in which gas is produced from an upper portion of the formation and a waste gas is injected into a lower portion of the formation to dispose of the waste gas. The waste gas is injected within a 3000 foot (914 m) radial distance from the production of the gas. The injection and production can be carried out using one well or a plurality of wells.

Abstract: A method of treating and completing a well includes positioning a downhole tool within a well. The downhole tool includes an elongated body defining a central passageway and including a plurality of production openings and at least one frac opening, a frac mandrel disposed within the central passageway, and a packer disposed about the elongated body. The method further includes securing the downhole tool in the well by the packer, fracing a formation through the frac opening, and producing a fluid from the formation through the production openings.

Abstract: A groundwater treatment system, which includes subterranean inlet, treatment, and outlet portions. The inlet portion is configured to collect groundwater from an aquifer. The treatment portion includes a replaceable treatment media and is configured to receive the groundwater from the inlet portion and expose the groundwater to the treatment media. The outlet portion is configured to receive groundwater from the treatment portion and expel the groundwater to the aquifer.

Abstract: A tubing string assembly is disclosed for fluid treatment of a wellbore. The tubing string can be used for staged wellbore fluid treatment where a selected segment of the wellbore is treated, while other segments are sealed off. The tubing string can also be used where a ported tubing string is required to be run in in a pressure tight condition and later is needed to be in an open-port condition.

Abstract: One or more templates are provided for circulating fluids in a main well bore and for drilling and completing at least one offset well bore from the main well bore. Each template has a body, an inlet leg, a main outlet leg, and an offset outlet leg. A straddle assembly is mounted in the template to configure the template for fluid circulation. The straddle assembly, in cooperation with the inlet and main outlet legs, effects a downhole flow path which directs fluids from the inlet leg through body of the template and out the main outlet leg, bypassing the offset outlet leg. The straddle assembly is distally displaced from the template to reconfigure the template for drilling. A diverter is placed in the body of the template upon displacement of the straddle assembly to define a drill string path from the inlet leg to the offset outlet leg. The offset well bore is drilled by conveying a drill string through the drill string path.

Abstract: Pollutants are extracted from sub-surface water using an aqueous solution of cyclodextrin and a vertical circulating well. Complexes of the pollutant and cyclodextrin are recovered from the bottom of the well. When the pollutant is volatile, the complexes are separated into pollutant and cyclodextrin by air stripping.

Abstract: A method and an apparatus for injecting a fluid into a borehole. The method includes the step of injecting an injection fluid into a primary injection zone in a borehole at an injection fluid pressure. The primary injection zone is bounded by a proximal injection zone interface and a distal injection zone interface. The proximal injection zone interface and the distal injection zone interface are maintained at pressures which are substantially balanced with the injection fluid pressure. The apparatus includes a body adapted for passage through a borehole, at least four radially extendable and retractable zone interface elements spaced longitudinally along the body which when extended define at least three zones along the body, a zone interface element actuator for selectively extending and retracting the zone interface elements, and a fluid delivery system for delivering a fluid to each zone.

Abstract: Apparatus and methods are disclosed for sequentially treating multiple zones in underground formation in a single trip of the well treatment work string. In the one embodiment, the work string includes composite tubing having electrical conductors embedded within the walls, the conductors enabling power transmission and two way communication between the surface and the sensor or detectors downhole so that real time data can be sensed and communicated. Isolation packers are actuated via electrical signals from the surface communicated to the bottom hole assembly via the conductors. A detector located in the bottom hole assembly may be provided to detect perforations or other anomalies in the casing, such as joints, enabling the surface controller to position packers properly in blank segments of casing so that well intervals can be properly isolated and the adjacent formation effectively treated.

Abstract: It is common in oil extraction operations to reinject produced gas and\or water back into hydrocarbon bearing formations in order to maintain formation pressure. Conventional production facilities normally flow all formation fluids to the surface and subsequently reinject the required fluids back into the formation, which can be extremely inefficient due to the high power input required to overcome the large pressure differential between the surface and formation level. A production fluid handling method and apparatus for separating downhole at least gaseous and liquid components (16, 18, 20) of fluid produced from a hydrocarbon bearing formation (12), and reinjecting at least a portion of the gaseous and liquid components (16, 18, 20), as required, back into the formation (12). Re-injection also occurs downhole.

Abstract: An apparatus and method for enhancing oil recovery through improved injection well performance is provided, wherein a fluid is injected into the well bore at a pressure Pi, and a downhole fluid-actuated engine and pump assembly is employed as a booster in order to generate a high pressure output at pressure Ph greater than Pi and a low pressure output at pressure Pl lower than Pi; the respective output streams are directed to lower and higher permeability geological strata adjacent the well bore in order to increase production.

Abstract: The present invention relates to recovery and treatment of underground mineral deposits by multitude of directional and multi-functional wells drilled from the super daisy shaft through which the dynamics and dragging forces of fluid means is developed synergistically with complex rubblization and other techniques, and more particularly where the same wells assist in creation of the pressurized barriers to contain the exploitation field for treatment and recovery of minerals.

Abstract: A tubing string assembly is disclosed for fluid treatment of a wellbore. The tubing string can be used for staged wellbore fluid treatment where a selected segment of the wellbore is treated, while other segments are sealed off. The tubing string can also be used where a ported tubing string is required to be run in in a pressure tight condition and later is needed to be in an open-port condition.

Abstract: When production testing a permeable first formation, fluid flowing out from the first formation is subjected to a pressure measurement and a flow rate control. In order to avoid bringing up the fluid flowing out during the production test to a surface position, where the fluid's inherent explosion and fire risk as well as poisonousness would cause substantial problems, a fluid flow path is arranged for fluid transfer between the first formation to be production tested and a second permeable formation. The fluid flow path is preferably constituted by a channel-forming pipe. From this channel, the second permeable formation receives the fluid and keeps it for some time. In the position of use, the apparatus is assigned sealing devices such as annulus packers, which are placed such that fluid flow between the formations is limited to only follow the fluid flow path.

Abstract: A subterranean well production system utilizes a single well to perform both hydrocarbon fluid production and water dumpflooding processes. The well has a primary wellbore that is communicated with first and second subterranean zones respectively containing hydrocarbon fluid and higher pressure water. A second, lateral wellbore extends from the primary wellbore and communicates with the first zone. A remotely controllable routing system, including a valved production tubing structure extending through the primary wellbore, is operable to (1) flow hydrocarbon fluid from the first zone to the surface via the production tubing and (2) simultaneously dumpflood water from the second zone into the first zone, via the production tubing, to increase the pressure within the first zone and thereby increase the hydrocarbon fluid production rate.

Abstract: An apparatus and method for enhancing oil recovery through improved injection well performance is provided, wherein a fluid is injected into the well bore at a pressure P1, and a downhole fluid-actuated engine and pump assembly is employed as a booster in order to generate a high pressure output at pressure Ph greater than P1 and a low pressure output at pressure P1 lower than P1; the respective output streams are directed to lower and higher permeability geological strata adjacent the well bore in order to increase production.

Abstract: A ported sub treatment system in which well treatment materials are pumped into an uncased portion of a well through a pipe having a number of holes at specific locations along its length such that these materials are able to be distributed as desired by the operator, through these holes, along the length of the well. The treatment system is also able to provide sufficient pressure such that treatment materials are able to penetrate or fracture the rock surrounding the well, if necessary.

Abstract: An apparatus and method for enhancing oil recovery through improved injection well performance is provided, wherein a fluid is injected into the well bore at a pressure Pi, and a downhole fluid-actuated engine and pump assembly is employed as a booster in order to generate a high pressure output at pressure Ph greater than Pi and a low pressure output at pressure Pl lower than Pi; the respective output streams are directed to lower and higher permeability geological strata adjacent the well bore in order to increase production.

Abstract: A system for reservoir control. The system allows segregated production of fluids, e.g. water and oil, to control the fluid-fluid interface. Downhole sensors are utilized in providing data about the location of the interface. This permits the proactive monitoring and control of the interface prior to unwanted intermingling of fluids, e.g. oil and water, during production.

Abstract: One embodiment of my invention comprises a tool string for testing a wellbore formation that includes a production inlet, an injection outlet, and a sampler apparatus. Fluid is taken from a production zone, into the tool string through the production inlet, out of the tool string through the injection outlet, and into the injection zone. Within the interior of the tool string, the sampler apparatus takes samples of the fluid flowing therethrough. In another embodiment, a large volume of sample fluid is trapped within the interior of the tool string, such as between two valves, and is removed from the wellbore along with the tool string subsequent to the test. In another embodiment, the tool string includes at least one perforating gun to perforate one of the production and injection zones. The tool string may also include two perforating guns to perforate both the production and injection zones.

Abstract: Methods and compositions for stimulating multiple intervals in wells by diverting well treatment fluids into multiple intervals by alternately displacing diverting agent from the annulus into a subterranean formation and displacing treatment fluid from a tubing string into the subterranean formation.

Abstract: Method and apparatus for delivery of chemical reagents to a subterranean body of soil and groundwater to destroy or enhance mobility of organic compounds using a riser insertable in a borehole having spaced permeable sections separated by a non-permeable section and wherein the reagents are introduced from a source by a pressurization apparatus.

Abstract: A system for use in a wellbore includes a tubing having an inner bore and flow switcher assembly. The flow switcher assembly including a first conduit coaxial with the tubing inner bore and a second conduit formed annularly around the first conduit. One of the first and second conduits is adapted to carry production fluid flow, and the other one of the first and second conduits is adapted to carry injection fluid flow. The flow switcher assembly includes ports in communication with the first and second conduits to enable cross-over flow. In addition, one or more valves may be provided to control fluid flow through the ports.

Abstract: When production testing a permeable first formation, fluid flowing out from the first formation is subjected to a pressure measurement and a flow rate control. In order to avoid bringing up the fluid flowing out during the production test to a surface position, where the fluid's inherent explosion and fire risk as well as poisonousness could cause substantial problems, a fluid flow path is arranged for fluid transfer only between the first and second formations. The fluid flow path which, in a suitable apparatus, is constituted by a channel-forming pipe. From this channel, the second permeable formation receives the fluid and keeps it for some time. In the position of use, the apparatus is assigned sealing devices such as annulus packers, which are placed such that fluid flow between the formations is limited to only follow the fluid flow path.

Abstract: A method and system for producing a mixed gas-oil stream through a tubing wherein at least a portion of the gas is separated from the stream and flowed through a restriction in the tubing to cool the separated gas and reduce its pressure to thereby retain larger amounts of liquid (i.e. condensate) in the gas-oil stream which is to be produced to the surface. The separated gas is compressed downhole before it is injected into a downhole formation.

Abstract: A tool and method are disclosed for injecting various treatment fluids into a formation surrounding an underground borehole. The tool comprises at least three axially spaced swab assemblies which define at least two annular spaces between the tool body and the wellbore. In use the tool is moved through the wellbore whilst a first treatment fluid such as a sand consolidation agent or production stimulation chemical, is pumped via a first annular space into the formation and a second treatment fluid, such as an overflush fluid, is pumped via a second annular space into the formation. The tool allows accurate and continuous injection of various treatment fluids over long intervals into the formation without requiring cycling to new fluids.

Abstract: A pair of vertically spaced, parallel, co-extensive, horizontal injection and production wells and a laterally spaced, horizontal offset well are provided in a subterranean reservoir containing heavy oil. Fluid communication is established across the span of formation extending between the pair of wells. Steam-assisted gravity drainage (“SAGD”) is then practised by injecting steam through the injection well and producing heated oil and steam condensate through the production well, which is operated under steam trap control. Cyclic steam stimulation is practised at the offset well. The steam chamber developed at the offset well tends to grow toward the steam chamber of the SAGD pair, thereby accelerating development of communication between the SAGD pair and the offset well. This process is continued until fluid communication is established between the injection well and the offset well.