摘要:
The permeability of a subterranean oil-bearing formation is controlled by the injection of an aqueous solution of a cross-linked block copolymer containing polar and non-polar segments, with the polar segments generally making up as least 50 percent, usually 60 to 99 percent, of the copolymer. The polar segments are derived from an alkylene oxide and the non-polar segments from styrene or an alkyl styrene either by itself or with a diene. The copolymers are cross-linked with an amino resin or a combination of a phenolic and a water-dispersible aldehyde component. The resulting copolymer gels are stable at low pH conditions, such as those of CO.sub.2 flood conditions.
摘要:
A method of enhancing the amount of oil recovered from a subterranean oil-bearing formation by controlling the profile of the formation by introducing a predetermined first amount of a permeability control agent in a non-gelatinous state into the formation so that it contacts at least a portion of the formation. A portion of the pores of the formation are plugged by allowing contact to be maintained for a sufficient period of time allowing the first portion to gel. The first amount constitutes a portion of the total amount required to improve the profile of the formation. A predetermined second amount of permeability control agent is thereafter introduced, in a non-gelatinous state, into the formation which contacts the first amount and the portion of the formation not contacted by the first amount for a time period sufficient to gelatinize the second amount so as to plug the remaining unproductive pores of the formation. The second amount constitutes the remaining portion of the total amount required to improve the profile of the formation. Complete profile control is attained while not requiring any greater quantities of permeability control agent than those typically required in a single step profile control treatment.
摘要:
A composition of matter where a polymer is partially hydrolyzed to form a polymer intermediate which can be gelled. Said polymer intermediate consists of 2-acrylamido-2-methylpropane-3 sulfonate, N-vinyl-N-methyl acetamide, acrylamide, and an alkali metal hydroxide. When cross-linked with a transitional metal ion said polymer intermediate forms a gel suitable for profile control use under harsh conditions. Said gel is exceptionally stable under the hot temperature and saline conditions encountered in profile control usage during a water flood or carbon dioxide oil recovery operation.
摘要:
A method for selectively closing pores in a formation's zone of greater permeability. A rehealable Xanthan or Alcaligenes biopolymer in an aqueous medium is combined with an organic or transition metal cross-linker which forms a first stage selective ex-situ gel. Second stage non-selective gel precursors are also included. The second stage gel comprises a polymer cross-linked with organic cross-linkers so as to form an in-situ gel more able to withstand formation conditions. The combination is injected into a formation after the first stage gel forms where it selectively enters a zone of greater permeability carrying therewith said non-selective gel. Once in the formation's zone of greater permeability, the gel reheals and forms a rigid gel having the desirable characteristics of the non-selective gel.
摘要:
A composition capable of selectively plugging highly permeable zones in a subterranean formation. The composition forms a gel subsequent to its injection into the formation via an injection well. The composition comprises an aqueous solution of a welan gum heteropolysaccharide biopolymer produced by the fermentation of a microorganism of the genus Alcaligenes, a phenolic compound, an aldehyde and water. The compositions of this invention will form stable gels even in low salinity brines. Also provided is a process for selectively plugging regions of higher permeability within an oil-bearing subterranean formation to improve sweep efficiency during a fluid flood oil recovery process using the gel-forming compositions of this invention.
摘要:
A composition capable of selectively plugging highly permeable zones in a subterranean formation. The composition forms a gel subsequent to its injection into the formation via an injection wall. The composition comprises an aqueous solution of a welan gum heteropolysaccharide biopolymer produced by the fermentation of a microorganism of the genus Alcaligenes, a phenolic compound, an aldehyde and water. The compositions of this invention will form stable gels even in low salinity brines. Also provided is a process for selectively plugging regions of higher permeability within an oil-bearing subterranean formation to improve sweep efficiency during a fluid flood oil recovery process using the gel-forming compositions of this invention.
摘要:
The permeability of a subterranean oil-bearing formation is controlled by the injection of an aqueous solution of a cross-linked block copolymer containing polar and non-polar segments, with the polar segments generally making up at least 50 percent, usually 60 to 99 percent, of the copolymer. The polar segments are derived from an alkylene oxide and the non-polar segments from styrene or an alkyl styrene either by itself or with a diene. The copolymers are cross-linked with an amino resin or a combination of a phenolic and a water-dispersible aldehyde component. The resulting copolymer gels are stable at low pH conditions, such as those of CO.sub.2 flood conditions.
摘要:
A ball bearing swivel connectable between the output end of a fuel dispensing hose and the input end of a fuel dispensing nozzle to allow multi-plane rotation of the nozzle The swivel includes three segments, a nozzle fitting, a midsection, and a hose fitting. The end segments are joined to the midsection by ball bearing races which allow each segment to rotate 360° relative to the adjacent segment. The ball bearing races are positioned between a first and second O-ring seal to prevent dust or dirt accumulation and fuel leakage. The ball bearing races allow rotation of the swivel under increased fluid pressure conditions.
摘要:
A fuel nozzle assembly for dispensing fuel from a source to a container includes a body defining a fuel flow path and a vapor recovery path. The nozzle includes a venturi valve in the fuel flow path which defines a venturi port and a diaphragm valve positioned in the vapor recover path, The diaphragm valve has a control section having a control port which is in fluid communication with the venturi. The diaphragm valve is normally spring biased closed. When gas flows through the venturi and over the venturi port, it creates a vacuum in the diaphragm control section sufficiently strong to open the diaphragm valve so that recovered vapors may be returned to a source of fuel, or other collection area, such as an underground storage fuel tank.
摘要:
A vapor valve for use in conjunction with the fuel dispensing nozzle for capturing vapors returned through the nozzle to a storage area, the nozzle incorporating a body, a spout extending forwardly therefrom, and the nozzle having an operating latch pin and housing for normally providing for opening or shut-off of the nozzle during a dispensing function, a vapor passageway extending through the spout, communicating into the latch pin housing, and extending through the nozzle body for return of vapors back to a storage area, and a latch ring operatively associated with the latch pin and providing for opening or closure to the vapor port of the latch pin housing to furnish its opening while fuel is being dispensed for return of vapors to a storage area, or when the fuel dispensing function is curtailed, providing for an upward shifting of the latch ring within the housing for closure of its associated vapor port and preventing the escape of vapors to the atmosphere.