Patents Represented by Attorney K. D. Van Tassel
  • Patent number: 6107531
    Abstract: A method for inhibiting the formation of clathrate hydrates in a fluid having hydrate-forming constituents involves treating the fluid with an inhibitor comprising a substantially water soluble polymer having a polymer backbone .with a pendant C.sub.1 --C.sub.3 alkyl group; the polymer having an average molecular weight between about 1,000 and about 6,000,000. Preferably, the pendant alkyl group is a methyl group. The rate of nucleation, growth, and/or agglomeration of gas hydrate crystals in a petroleum fluid stream Is reduced using the alkylated polymer backbone inhibitor, thereby inhibiting the formation of a hydrate blockage in the pipe conveying the petroleum fluid stream. Test results are disclosed which unexpectedly show that alkylating the polymer backbone with a methyl group will produce a subcooling for the alkylated polymer that is at least about 2.degree. F. (about 1.1.degree. C.) greater than its nonalkylated counterpart.
    Type: Grant
    Filed: January 6, 1998
    Date of Patent: August 22, 2000
    Assignee: ExxonMobil Upstream Research Company
    Inventors: Karla S. Colle, Christine A. Costello, Larry D. Talley, Russell H. Oelfke, Enock Berluche
  • Patent number: 5600044
    Abstract: A method for inhibiting the formation of clathrate hydrates in a fluid having hydrate forming constituents is disclosed. More specifically, the method can be used in treating a petroleum fluid stream such as natural gas conveyed in a pipe to inhibit the formation of a hydrate restriction in the pipe. The hydrate inhibitors used for practicing the method are substantially water soluble polymers formed from a N-substituted acrylamide having two nitrogen substituent groups, R.sub.1 and R.sub.2, where R.sub.1 is a hydrocarbon group having from one to ten carbon atoms and zero to four heteroatoms selected from the group consisting of nitrogen, oxygen, sulfur, and combinations thereof, and R.sub.2 is a hydrogen atom or a hydrocarbon group having from one to ten carbon atoms selected from the group consisting of carbon, nitrogen, oxygen, and sulfur; alternatively, R.sub.1 and R.sub.
    Type: Grant
    Filed: May 24, 1995
    Date of Patent: February 4, 1997
    Assignee: Exxon Production Research Company
    Inventors: Karla S. Colle, Christine A. Costello, Russell H. Oelfke, Larry D. Talley, John M. Longo, Enoch Berluche
  • Patent number: 5491269
    Abstract: A method for inhibiting the formation of clathrate hydrates in a fluid having hydrate forming constituents is disclosed. More specifically, the method can be used in treating a petroleum fluid stream such as natural gas conveyed in a pipe to inhibit the formation of a hydrate restriction in the pipe. The hydrate inhibitors used for practicing the method are substantially water soluble polymers formed from a cyclic imino ether. Some examples of such inhibitors include various N-acyl polyalkyleneimines, such as N-acyl substituted polyethyleneimine, N-acyl substituted polypropyleneimine, N-acyl substituted polybutyleneimine, N-acyl substituted polypentyleneimine and copolymers thereof. Also, such N-acyl substituted polyalkyleneimines can be used in various ratios with other substantially water soluble polymers and copolymers. Preferably, a solvent such as water, brine, alcohol, or mixtures thereof is used to produce an inhibitor solution or mixture to facilitate treatment of the petroleum fluid stream.
    Type: Grant
    Filed: September 15, 1994
    Date of Patent: February 13, 1996
    Assignee: Exxon Production Research Company
    Inventors: Karla S. Colle, Russell H. Oelfke
  • Patent number: 5490940
    Abstract: A method is disclosed for removing spilled oil from shorelines, other solid surfaces, or from the surface of a body of water by adding to the surface a mixture of fine hydrophilic mineral solids dispersed in an aqueous liquid that interacts with the oil to form buoyant mineral fines-oil floccules. These floccules reduce the tendency of the oil to adhere to solid surfaces or to recoalesce, thus facilitating dispersion and removal of the oil.
    Type: Grant
    Filed: April 8, 1994
    Date of Patent: February 13, 1996
    Assignee: Exxon Production Research Company
    Inventors: James R. Bragg, Shan H. Yang
  • Patent number: 5371330
    Abstract: The current invention is an apparatus useful for generating seismic waves with an enhanced signal to noise ratio. The enhanced signal is produced at a fundamental resonant frequency, and multiples thereof, by producing a near zero acoustic pressure condition around and beyond each end of the apparatus having an intermediate acoustic source. Such a near zero acoustic pressure condition is established preferably by either (1) using two end acoustic sources to produce a destructive interference effect with the acoustic output of a third acoustic source postioned therebetween, or (2) using two end acoustic capacitors or resonators to produce a near zero impedance condition at each end of the apparatus. The enhanced signal may be produced over a range of frequencies, including both resonant and nonresonant frequencies, by creating a high impedance condition experienced by the intermediate source and hence a high acoustic pressure around the intermediate region of the apparatus.
    Type: Grant
    Filed: August 6, 1993
    Date of Patent: December 6, 1994
    Assignee: Exxon Production Research Company
    Inventor: Graham A. Winbow