A method of extracting bitumen from a subsurface tar sand bed wherein a shell of frozen earth is formed around the periphery of at least a portion of the tar sand bed, followed by recovering bitumen from such portion of the tar sand bed within the shell of frozen earth by suitable means such as, for example, solvent extraction. Also disclosed is apparatus for freezing the earth surrounding one of a plurality of boreholes drilled in the earth within earth freezing distance of each other around the periphery of such portion of the tar sand bed. The apparatus comprises concentric outer and inner conduits with the outer conduit having two strips of thermal insulation extending along substantially the full length of the exterior surface of the outer conduit, separated by two strips, preferably longitudinally finned, of relatively high thermal conductivity extending along substantially the full length of the exterior surface of the outer conduit so as to provide a predetermined freezing pattern about the axis of a borehole when refrigerant is circulated through the apparatus.

Method and apparatus for treatment of subsurface formations

A method and a system for offshore production of liquefied natural gas, wherein natural gas is supplied from an underground source (4) to a subsea production plant (1). The gas is transferred under a high pressure directly from the production plant (1) to an LNG tanker (6), the transfer taking place through a pipeline (5) surrounded by sea water and causing the temperature of the high pressure gas to be lowered to a desired low temperature. This gas is supplied to a conversion plant (12) provided on the LNG tanker (16) and arranged for converting at least a part of the gas to liquid form, and the liquefied gas is transferred to storage tanks (17) on board the vessel (6). When the storage tanks (17) on the LNG tanker (6) are filled up, the pipeline is disconnected from the LNG tanker and connected to another similar tanker, the pipeline being permanently connected to a submerged buoy (8) which is arranged for introduction and releasable securement in a submerged downwardly open receiving space (11) in the tanker (6), and which is provided with a swivel unit for transfer of gas under a high pressure.

Method and system for offshore production of liquefied natural gas

The delivery system of the invention consists of a pair of LNG fuel tanks mounted on a vehicle. A solenoid valve associated with each tank allows the vehicle operator to select the tank from which LNG is to be delivered to the engine. An automatic override system is provided whereby if the pressure in the non-selected tank rises above a predetermined level, the operator's tank selection is overridden and gas from the non-selected tank is used until the pressure falls below the predetermined level. This override system eliminates the need to vent gas to the atmosphere to avoid pressure building up and thereby eliminates waste of the LNG. Each tank is also provided with a pressure building capability such that the gas will always be delivered to the engine with sufficient pressure. The system is designed such that LNG from a stationary low pressure storage tank can be delivered at high pressure to refuel the tanks. Finally, a variable insulation barrier is provided in the fuel tanks to minimize heat transfer between the LNG and gas head.

LNG delivery system for gas powered vehicles

This invention provides a closed-loop system for in situ testing of formation fluid conditions and for selectively collecting substantially mud filtrate free formation fluid samples at original formation conditions. The system contains an elongated member having a probe that is sealingly placed against the wellbore formation to withdraw formation fluids. A surface controlled pump controls the flow of a fluid from the formation into a flow line placed in the elongated member. A pressure sensor provides downhole hydrostatic pressure and differential pressure sensor provides difference in pressure across two fixed points across the flow line. A temperature sensor and resistivity device are utilized in a conventional manner to respectively provide downhole fluid temperature and the resistivity of the formation fluid. The system determines the density of the formation fluid in the flow line from the differential pressure and in response thereto controls the fluid flow into the flow line to selectively collect the formation fluid samples that are substantially free from any mud filtrates while maintaining the fluid pressure above the bubble point pressure of the fluid. This invention provides a method for retrieving and collecting formation fluids from a zone of interest in a wellbore at the original formation conditions.

Apparatus and method for retrieving formation fluid samples utilizing differential pressure measurements

The present invention is directed to a self-contained refrigerant recovery and purification system capable of removing gaseous refrigerants from a disabled refrigeration unit for cleaning acid and impurities from the refrigerant so that the refrigerant can be reused or saved rather than being lost to the atmosphere or otherwise wasted. In addition to the feature of saving, cleaning and returning the refrigerant to the repaired refrigeration unit, the present invention can be used as a temporary condensing unit, or for clearing oil restrictions from lines in the refrigeration unit with a high-pressure build-up feature, or as a vacuum pump.

Refrigerant recovery and purification system

Method and apparatus for testing formations

A single point mooring and transfer facility is provided which comprises a floating buoy, a submerged platform, means for maintaining the floating buoy in position relative to the platform and a conduit means between the platform and the buoy. The conduit means has a coiled portion with its axis substantially vertical. The coiled portion provides the necessary flexibility between the floating buoy and the submerged platform, thus avoiding any requirement for flexible hoses and/or undersea swivel connections.

Edwin E Reed

Papers

Method and apparatus for testing formations

Single point mooring buoy and transfer facility

Fluid handling structure

Storage and pressure control of refrigerated liquefied gases

Lpg transport loading