Showing papers on "Annulus (oil well) published in 1970"

Apparatus for controlling well pressure

Abstract: There is disclosed apparatus which includes a choke for connection to the annulus between a well bore and a drill string extending into the bore, and a means for operating the choke to impose a back pressure on drilling fluid in the annulus either manually or automatically in response to certain well characteristics so as to maintain a predetermined pressure differential between it and formation fluid at the bottom of the well bore.

Apparatus for selectively producing and testing fluids from a multiple zone well

Abstract: APPARATUS FOR SELECTIVELY PRODUCING AND TESTING FLUIDS FROM A MULTIPLE ZONE WELL INCLUDING A PACKER SEALING OFF ONE OF THE ZONES ANOTHER AND A TUBING STRING IN FLUID COMMUNICATION WITH THE LOWER ZONE A LOWER ZONE CROSS-OVER IS DISPOSED ABOVE THE PACKER IN FLUID COMMUNICATION WITH THE TUBING STRING FOR DIVERTING FLUIDS FROM THE LOWER ZONE AND INTO THE ANNULUS BETWEEN THE TUBING STRING AND THE WELL AN UPPER ZONE FLUID INLET IS IN FLUID COMMINICATION WITH THE TUBING STRING ABOVE THE LOWER ZONE CROSS-OVER A PUMP EXTENSION IS SELECTIVELY MOVABLE IN THE TUBING STRING BETWEEN A POSITION SEALING OFF THE TUBING STRING AT ONE POINT ABOVE THE LOWER ZONE CROSS-OVER AND BELOW THE UPPER ZONE FLUID INLET AND AT ANOTHER POINT BELOW BOTH THE LOWER ZONE CROSSOVER AND THE UPPER ZONE FLUID INLET THE PUMP EXTENSION INCLUDES A FIRST NORMALLY OPEN FLUID INLET FOR REMOVING FLUIDS FROM BOTH OF THE ZONES AND A SECOND NORMALLY CLOSED FLUID INLET FOR REMOVING FLUIDS FROM THE LOWER ZONE

Well bore seal apparatus for closed fluid circulation assembly

Abstract: A well bore seal apparatus for a closed fluid circulation assembly, wherein one or more seal means are disposed to engage a well bore for sealing off the annulus externally of the closed fluid circulation assembly so that air, drilling mud, water and other fluids are sealed off from the annulus during drilling operations. This invention is especially suitable for drilling in permafrost, solid frozen ground and other solid formations which might be adversely affected by the presence of fluid in the annulus during drilling. The seal apparatus may also serve as a stabilizer during drilling, particularly when seal means are disposed at longitudinally spaced points on the assembly.

Method of gravel-packing a production well borehole

Abstract: A method of gravel-packing a well borehole extending into an interval of a hydrocarbon-bearing subterranean earth formation by determining the median size of the sand grains in the interval and forming a pumpable slurry of liquid containing granular particles having a relatively narrow range of grain sizes with a median grain size from about 5 to 7 times larger than the median size of grains in the interval. Perforations are formed in a conduit sized to exclude passage of substantially all the slurried granular particles and the conduit is positioned in the well borehole at a depth adjacent to the interval, thereby forming an annulus between the conduit and the interval. A fluid including the slurry is then flowed into the annulus and into contact with the exterior of the conduit until the annulus is substantially filled with the granular particles. Fluids are then flowed from an injection well borehole into the gravel-packed well borehole for recovering of hydrocarbon-bearing fluids therefrom.

Well cross-over apparatus for selective communication of flow passages in a well installation

Abstract: A well flow system, including one or more flow conductors disposed in a well having a casing annulus, means interconnecting the conductor or conductors and/or annulus, and a fluid-actuated valve in at least one of the flow conductors for selectively communicating the conductor or conductors and/or the annulus of the well responsive to a pressure differential applied across the valve and controlled from the surface. The flow system is adapted to well producing and well treating procedures. A number of different flow conductor, well annulus, and valve arrangements are shown with provision in each system disclosed for hydraulic control of a down-hole valve to communicate selected combinations of flow passages of the conductors and the well annulus.

Through tubing well cleanout method using foam

Abstract: A method of cleaning out a well having a production tubing located therein without removing the production tube from the well by providing a flushing tube inside the production tube, generating pre-formed foam having a liquid volume to gas volume ratio in the range of from 0.05 to 0.1, injecting said foam into the flushing tube and down the well at a pressure within the range of from 350 to 1,000 or more psi and circulating the foam up the annulus between the production tube and the flushing tube while maintaining the annular velocity of the foam within the range of from 600 to 1,000 feet per minute.

Air drilling method using controlled split stream

Abstract: Method and apparatus for drilling and for obtaining uncontaminated formation samples with an air hammer by flowing compressed air down through the tubing annulus of a dual pupe string to a novel sub, where the flow divides to enable part of the air to power the air hammer while the remaining air flow is directed into the hole annulus. The spent air exhausts from the bit face and carries cuttings back into the sub and into the inner tubing string. An enlargement formed on the sub exterior prevents comingling of the samples with material from the borehole annulus.

Down-hole air hammer

Abstract: A down-hole air hammer embodying an outer housing structure connectible to a string of rotatable drill pipe through which compressed air is conducted. Upper and lower cylinder sleeves within the housing structure define an upper high pressure air annulus and a lower low or exhaust pressure annulus, the cylinder sleeves being longitudinally spaced from each other. A hammer piston reciprocates in the sleeves, having an enlarged intermediate portion slidable along the housing structure between the cylinder sleeves, there being small diameter upper and lower pistons slidable along the upper and lower cylinder sleeves, respectively, to provide a large intermediate piston area over which high pressure air can act to increase the impact force of the piston on a companion anvil secured to the drill bit rotatable by the housing structure. The high pressure air exhausts through the housing structure above the bit to provide sufficient air volume for carrying the cuttings upwardly through the annulus surrounding the drill pipe to the top of the hole being drilled.

Method and apparatus for gas-lift operations in oil wells

Abstract: A conventional gas-lift system is installed in an oil well at the initial completion and fitting-out of the well. Each gas-lift valve is provided with a blocking device which closes in response to hydrostatic pressure in the casing annulus greater than the dome pressure in the gas-lift valve assembly. Liquids in the casing annulus may be displaced through a sleeve valve in the tubing by gas injection pressure greater than the hydrostatic pressure, after which the gas injection pressure may be reduced to open the blocking devices for gas flow into the tubing string.

Well for transporting hot fluids through a permafrost zone

Abstract: A well adapted to transport hot fluids through a permafrost zone comprising a surface conductor, a short section of refrigerated casing adapted to support the upper section of the well without melting of the surrounding permafrost, a surface casing extending through the permafrost, production casing and production tubing. All casing strings are supported in the well so that the upper sections are in compression. Pressure integrity between casing strings is maintained by packing glands in the well head. Also, a short section of casing can be provided in the annulus exterior of the surface casing to provide a separately enclosed refrigeration reservoir, or to provide for circulation of refrigerant.

Well insulation method

Abstract: A method for thermally insulating a well which may be used in a thermal process for oil recovery. The well is insulated by boiling a solution containing a water-soluble alkali metal silicate and a foaming agent in contact with the well tubing to form a coating of alkali metal silicate on the tubing. The foaming agent assists in removing excess silicate solution from the well annulus and improves the quality of the coating on the tubing.

Retrivable Well Packer

Abstract: 1,199,086. Well packers. SCHLUMBERGER TECHNOLOGY CORP. 29 Oct., 1968, No. 51206/68. Heading E1F. A well packer comprises a mandrel 11, a hollow tubular body 23 slidably positioned on the mandrel, packing means 28, anchor means (36) below the packing means, fluid by-pass passage 72 extending along the mandrel and communicating with the well bore above, at 74, and below the packing means, valve means 79 on the mandrel and engageable with a valve seat 75 on the body 23 to close the passage, a piston 109 connected to the mandrel and operative in response to the tubing pressure - i.e. the pressure below the packing means - exceeding the annulus pressure - i.e. the pressure above the packing means -to exert a force on the mandrel to oppose the force thereon of this pressure difference, and a piston 112 operative in response to the annulus pressure exceeding the tubing pressure to exert force on the mandrel to counterbalance the force thereon exerted by the pressure difference. The piston 109 is slidable within the body 23 and has the annulus pressure applied to the bottom surface through openings 74 in the body, and the tubing pressure applied to the top surface thereof through bypass passage 72, passageway 101 and bore 116. The piston 112 has the annulus pressure applied to the top surface thereof and the tubing pressure applied to the bottom surface. Accordingly when the annulus pressure exceeds the tubing pressure, piston 112 bears against piston 109 or as shown, or alternatively against a shoulder on the mandrel with the effective difference D in area between the two pistons being chosen to be equal to .the effective horizontal cross-sectional area of the mandrel on which the annulus pressure acts so that there is no net force on the mandrel. Above piston 112 slips are provided and are moved outwardly to engage the casing P by another double piston when the tubing pressure through passageway 101 exceeds the annulus pressure. Beneath the packer the tubular body 23 is jayed to the mandrel and has drag blocks which on un-jaying prevents the bottom portion moving downwardly with the mandrel so that the anchor means (36) can be set, and the tubing string weight applied to the packing means to set the packer.

Fluid Pressure Governors.

Abstract: 1,184,554. Valves. UNITED GAS INDUSTRIES Ltd. 5 June, 1967 [4 June, 1966], No. 24999/66. Heading F2V. A fluid pressure regulating valve, adapted to be associated with a gas operated appliance, comprises a casing formed of two parts, the lower part 1 carrying the inlet and outlet connections 5, 2 respectively, and the upper part 6 having attached to it, by means of a U-shaped sheet metal belt 24, an annulus 10 with a diaphragm 12 being interposed between the two, the two casing parts being removably secured together by bolts 26. Depending from the annulus is a cast or moulded cylindrical member 15 having formed therein a series of spaced apertures 29 and carrying a valve seat 16 engageable by a closure member 27 carried by, and depending from the diaphragm 12, a further diaphragm 13 extending between the closure member spindle 18 and the annulus 10. Removal of bolts 26 permits the withdrawal of the various valve components without disturbing the casing lower part 1. Disposed around member 15 is a cylindrical filter 30 which is held in position by flanges 14, 32 and 33, the arrangement being such that fluid from the inlet is forced to pass through the filter before flowing past the valve seat.

Coil tubing, nitrogen cut workover costs

Abstract: Shell Oil Co. is using a new well remedial technique to clean out plugged tubing and casing and effectively stimulate intervals without disturbing original well equipment. Developed by Nitrogen Oil Well Service Co. (NOWSCO), the procedure involves pumping nitrogen (N/sub 2/) down a string of 1/2-in. tubing which is uncoiled from a reel and injected into the production tubing string. In clean-out work, sand fill is circulated at high velocity up the 1/2-in./production tubing annulus. No pipe has been stuck using this procedure. In stimulation work, acid and N/sub 2/ are displaced simultaneously down the small annulus while N2 is pumped down the 1/2-in. string. Based on experience in 15 wells, the main advantages of the technique are as follows: (1) formation, damage from workover fluids is eliminated; (2) nitrogen can be circulated until sand entry stabilizes or the well bore remains free of fills; (3) nitrogen improves acid-treatment efficiency and spent acid can be immediately removed from the well; (4) recompletion intervals can be quickly and economically evaluated; and (5) size and weight of coiled tubing equipment will allow it to be moved readily onto offshore platforms. Cost of coiled tubing/nitrogen remedial operations depends on work done. Tabular datamore » show cost on 15 wells.« less