Abstract: There is disclosed a method and apparatus for treating produced water from a heavy oil thermal recovery unit to achieve water recovery and recycle levels of greater than 80% and as high as 100% to achieve zero discharge criteria. The method includes the initial steps of capturing the waste heat energy from the high pressure steam separator located downstream of the steam generators. Further, transferring the heat energy into a heated separator and reboiler exchanger to distill oil reservoir produced water and recover distilled water and a concentrated brine or solid product. The heated separator concentrated stream is circulated through the reboiler exchanger to maintain from 1% to about 50% mass vapour in the stream returning to the heated separator and prevent fouling and scaling. The apparatus includes a low pressure waste energy separator, heated separator and vapour compressor in combination with a forced circulation circuit to generate the distilled water.

Abstract: The bottom end of a coil tubing string is secured to the bottom end of a primary tubing string at ground surface. Usually the primary tubing string will be of larger diameter and is therefore stronger and stiffer than the coil tubing string. The strings are secured together with a locking assembly. This assembly comprises two interlocking members, one connected with each string. One of the interlocking members is meltable when exposed to elevated temperature. The primary tubing string and the coil tubing string are run together into the desired position in the wellbore. The primary tubing string acts to drag the coil tubing string along with it. Heat is then used to melt the interlocking member so that the strings can be separated. The heat can be provided by circulating steam or hot water or oil down to the assembly. Alternatively the downhole formation temperature may be sufficient to induce melting. Once separated, each string can be pulled or moved independently.

Abstract: Average grade oil sand is mixed with water to produce a low temperature (20-35.degree. C.), dense (1.4-1.65 g/cc) slurry. The slurry is pumped through a pipeline for sufficient time to condition it. Air is injected into the slurry after the last pump. The slurry density is adjusted to about 1.5 g/cc by adding flood water near the end of the pipeline. The slurry is introduced into a primary separation vessel slurry as it is introduced into the (PSV), excess air is vented from the PSV and a hot water underwash is used to heat the froth produced. Slurry loading to the PSV is greater than about 4.78 tonnes of oil sand/hour/square meter to reduce velocity gradient in the fluid in the vessel. Bitumen froth is recovered. When fed low grade oil sand, the process is modified by adding flotation aid chemicals to the slurry in the pipeline and subjecting the PSV tailings and middlings to secondary recovery with agitation and aeration in a secondary separation vessel.

Abstract: A batter board is interposed between an upper conveyor belt, that is discharging granular material, and a lower conveyor belt that is receiving it. The batter board is adapted to deflect the downwardly arching stream of material, to laterally adjust the location on the lower belt where the material is deposited. The extent of deflection practised is controlled in response to measurements which monitor the downstream belt side travel of the lower belt. The position of the batter board is adjusted with hydraulic actuators protected with a shock absorbing system.

Abstract: A dispersant, such as sodium silicate, is added to the process water of the hot water extraction process which recovers bitumen from oil sands. The dispersant disperses the ultrafine (less than 300 nm) particles, to reduce the formation of flocs and sludge in the tailings pond. The volume of the pond is such that the retention time of process water is sufficiently short (less than 6 weeks when using sodium silicate) to avoid reforming flocs from the dispersed ultrafines. The ultrafines content in the process water builds up as the water is repeatedly recycled from the pond to the extraction process. The ultrafines content stabilizes at a steady state concentration as some ultrafines are continuously removed from the process water when the tailings are delivered onto the "beach" of the pond and become trapped in the sand.

Abstract: Middlings from the primary separation vessel ("PSV") are recycled through a line to the PSV. The middlings are aerated with fine air bubbles using in line eductor/aerator assemblies. The aerated middlings are mixed as they are pumped through a line back to the PSV. Bitumen recovery from the PSV is increased as a result.

Abstract: Aerated bitumen froth containing bitumen, water, air and solids is the product of the hot water extraction process for recovering bitumen from oil sand. Measurements related to the water content of the froth can be obtained by measuring its resonant frequency in a calibrated output, open-ended microwave cavity. By also measuring the bulk density of the froth and assuming a constant relationship for the solids content, one can compute from the assembled data the output quality of the froth. The measurements can be taken repetitively at the vessel as the froth is produced and used to almost instantly provide froth quality information.

Abstract: The washer comprises an open-topped vessel having a tube mounted vertically and centrally therein. Post-primary bitumen froth is fed to the upper end of the tube. Pairs of down throw and up throw propellers mounted to rotate in the tube act to shear the froth as it passes down through the tube. At its lower end, the tube is closed off by a transverse wall. Slots are formed in the tube side wall to provide an exit. The sheared mixture thus changes direction as it leaves the tube. In the vessel chamber, solids and water sink downwardly and are removed as tailings through a bottom outlet. The sheared aerated bitumen rises and forms a new forth that is recovered in a launder. Middlings are withdrawn from the chamber and recycled to join the feed. The product froth is reduced in water and solids relative to the feed froth.

Abstract: As-mined, naturally water-wet oil sand is mixed at the mine site with hot water and NaOH to produce a slurry containing entrained air. The slurry is pumped through a pipeline and is fed directly to a conventional gravity separation vessel. The pipeline is of sufficient length so that, in the course of being pumped therethrough, sufficient coalescence and aeration of bitumen occurs so that, when subsequently retained in the gravity separation vessel under quiescent conditions, a viable amount of the bitumen floats, forms froth, and is recovered.

Abstract: The mixer circuit comprises a vertically oriented, open-topped mixer vessel having a cylindrical side wall terminating with a shallow conical bottom. The bottom wall forms a central bottom outlet. Recycled slurry and fresh water streams are fed tangentially to the inner surface of the vessel, thereby forming a vortex. The oil sand enters as a continuous, free-flowing stream moving along a downward trajectory; the stream impinges the vortex, wherein it is dispersed and mixed to create slurry. The slurry exits through the bottom outlet, is screened to remove oversize material, and enters a holding vessel. Part of the slurry in the holding vessel is recycled to the mixer vessel through a pipe loop incorporating a pump. The slurry is energized by the pump and functions to maintain and partly create the rapidly moving vortex that carries out the mixing and lump-disintegration actions. The balance of the slurry in the holding vessel is pumped out as product.

Abstract: This invention relates generally to a method for reducing the reactivity of steam or mixtures of steam and condensate in enhanced oil recovery. More particularly, the method of the invention comprises pH control through the injection or addition of either or both of ammonia and an ammonium salt of an organic or inorganic acid, such as ammonium chloride, to the feed water used to generate the steam or to the steam itself. This inhibits the dissolution of certain mineral groups, controls the migration of fines, inhibits the swelling of clays, controls chemical reactions in which new clay minerals are formed, and helps to prevent the precipitation of asphaltenes and the formation of emulsions as a result of steam injection.

Abstract: The present invention is based on the following:(1) that when tar sand is conditioned and diluted in the hot water extraction process, there are two classes of anionic surfactants (originating from carboxylate and sulfonate groups) present in the process water;(2) that each of these surfactants has the potential to dominantly influence the maximizing of primary froth production by the process;(3) that it is possible for a particular extraction circuit to determine the critical free surfactant concentration in the process water at which primary froth extraction is maximized for each of the two classes of surfactant;(4) and that it is possible to determine which of the two classes of surfactant will first (that is, at lowest NaOH addition) dominate the process when a particular tar sand feed is being processed.The present invention therefore involves:determining the critical free surfactant concentrations ("C.sub.cs.sup.O " and "C.sub.ss.sup.

Abstract: A device is provided for shearing an adherent layer of oil sand for removal from a major surface of a moving conveyor belt. A v-shaped formation of linearly-arrayed, spaced-apart, rotatable discs is suspended above or beneath the belt and brought into pressing engagement with the oil sand layer. As the discs rotate with the advancement of the belt, they function to cut through the layer, loosening it from the belt so it separates therefrom.

Abstract: A system is provided for controlling the feed rate of material being loaded onto a conveyor train of variable configuration to prevent overloading. The system involves monitoring the power drawn by the various drive motors of the train to establish which is the limiting conveyor under prevailing operating conditions. The instantaneous weight of feed material loaded onto the conveyor train, at its input end, is continuously measured and the current average feed rate is computed from the instantaneous weights measured over a pre-set time interval. A rolling average of the total load to be carried by the limiting conveyor downstream is computed from the average feed rate, taking into account the length of the limiting conveyor. The feed rate is then adjusted in response to the computed rolling average to thereby avoid overloading the limiting conveyor and optimize loading of the conveyor train.

Abstract: An improvement is provided to the known hot water process for extracting bitumen from mined oil sand. More particularly, a methodology is provided for the production of microbubbles of air, and it has been found that the so-produced microbubbles can be used in the primary flotation/settling step of the hot water process to yield increased bitumen recovery. More particularly, a steam stream and an air stream in admixture are injected via a submerged nozzle into a flowing aqueous stream. A plurality of finely dispersed microbubbles are formed. These microbubbles have a diameter less than about 100 microns. The stream of microbubbles is injected into the diluted aqueous tar sand slurry formed in the hot water process. The injection is practiced following the conditioning step and prior to the introduction of the slurry into the flotation/settling step.

Abstract: Froth, produced by induced air flotation in the hot water process circuit for extracting bitumen from tar sand, is recycled and added to the fresh slurry being introduced to the primary separation vessel. An increase in bitumen recovered as primary froth from the circuit is produced.

Abstract: A basket is removably inserted in the upper end of each drain tube in those interbed assemblies of a catalytic tower whose catalyst beds are to be removed upwardly by vacuuming. The basket has a grid for a bottom wall, so that catalyst particles thereabove are retained but fluid being treated in the tower can easily pass therethrough. The provision of the baskets makes it possible to downwardly drain spent catalyst from the lower bed sections while simultaneously vacuuming it upwardly from the upper bed sections.

Abstract: The hot water process is controlled in response to viscosity measurements taken in situ in the middlings in the primary separation vessel. The viscosity in the middlings is found to vary. Therefore, the layer of maximum viscosity is located and the viscosity at this depth is monitored. Adjustments are made to the process to keep this maximum viscosity below a pre-determined limit.

Abstract: The primary tailings and middlings are combined and fed to a vessel having the general form of a deep cone thickener. The feed is deflected outwardly and generally horizontally by a baffle, as it is delivered to the vessel. Simultaneously, the outwardly radiating layer of newly added feed is contacted from below by an upwelling stream of aerated middlings, which stream moves in parallel with the aforesaid layer. Bitumen froth is formed and recovered. The upwelling stream is provided by circulating middlings through eductor/aerator assemblies and a plenum chamber mounted centrally in the body of middlings in the vessel. A generally circular circulation of middlings is generated. In this manner, the newly added bitumen is quickly and efficiently recovered. Recirculation of middlings to the aeration zone yields an additional recovery of bitumen. Use of the deep cone ensures that the tailings from the vessel are relatively low in water and bitumen content.

Abstract: A steel connector for joining the steel cable ends of a conveyor belt is provided. The connector comprises a pair of tubular sleeves--one of which is slipped onto each cable end. Each sleeve has a bore having an inner section of reduced diameter relative to the outer section. The cable end is expanded radially, by driving a cone into its end, and then the expanded end is wedged tightly into the inner section of the sleeve to fix them together. Bridging members are threaded into the outer sections of the two sleeves to hold them together in lineal alignment. The bridging members are operative to permit the sleeves to flex relative to each other.