Patents Assigned to Dowell Schlumberger
  • Patent number: 5933945
    Abstract: Products and methods relating to composite materials and their use in coiled tubing is disclosed. The composite tubing is a pressurized means of conveying fluids downhole in a wellbore. It comprises a multilayered laminate that resists buckling within the wellbore and is fabricated into a hollow tube. The fibers are oriented in angular relationship to the longitudinal direction of the coiled tubing such as to provide appropriate strength and buckling characteristics to the coiled tubing. Further, the coiled tubing layered laminate may transmit signals representing data from downhole to the surface. In some embodiments, a composite disconnecting means comprised of a blend of fibers of different types or orientations is shown. The disconnecting means shows a failure load range corresponding to the failure characteristics of the fiber blend, the fiber blend having a predetermined failure limit.
    Type: Grant
    Filed: January 26, 1998
    Date of Patent: August 10, 1999
    Assignee: Dowell Schlumberger
    Inventors: Bart Thomeer, Robert Sorem
  • Patent number: 5280824
    Abstract: The outer, sealing cover of an inflatable packer comprises an alternating series of thick and thin annular portions which act to effect greater sealing stresses and to inhibit the propagation of cracks or tears in the elastomeric cover. Bonding with only portions of the underlying slats as well as a tapered contour and spacing from an end fitting act to help to retain the cover in its proper position during running and retrieval as well as decreasing the likelihood of the development of cracks and/or tears.
    Type: Grant
    Filed: November 25, 1992
    Date of Patent: January 25, 1994
    Assignee: Dowell Schlumberger
    Inventors: David M. Eslinger, Robert M. Sorem
  • Patent number: 4971147
    Abstract: An electrically conductive cable is held within the inner bore of a well tool connected to coiled tubing by a clamp which comprises a split ring having radially outwardly extending lug portions on the split ends of the ring. The lug portions are located within a longitudinally upward slot of a sleeve located within the inner bore of the well tool. Upon application of tensional force to the cable, the lugs of the split ring clamp are drawn into the taper thereby compressing the split ring in tighter engagement with the outer surface of the cable.
    Type: Grant
    Filed: March 27, 1989
    Date of Patent: November 20, 1990
    Assignee: Dowell Schlumberger
    Inventor: Bart Thomeer
  • Patent number: 4971775
    Abstract: A method for removing iron(III), copper(II), zinc(I) and nickel(II) from an effluent containing chelant (EDTA, DEPA, HOEDTA) comprising treating the effluent with a soluble calcium compound (e.g., Ca(OH).sub.2) CaCl.sub.2, Ca(NO.sub.3).sub.2) in a molar equivalent to the chelant in combination with a monovalent hydroxide to a pH greater than 12.4 and then adding an effective amount of a dialkyldithiocarbamate (e.g.; sodium-N,N-diethyldithiocarbamate) to precipitate the metal hydroxides and nickel dialkyldithiocarbamate. Heating the solution to about 180 F. further speeds up the removal of the nickel(II). The nickel concentration of spent chelant cleaning solution can be reduced to less than 1 ppm.
    Type: Grant
    Filed: June 30, 1987
    Date of Patent: November 20, 1990
    Assignee: Dowell Schlumberger
    Inventors: Edgar F. Hoy, Stanley B. McConnell
  • Patent number: 4913231
    Abstract: A method and apparatus for treating subterranean wells includes a tool supported on a one-piece support tube which operates to raise and lower the tool in the well to a position where well treatment is required. The tool provides inflatable packers and a selector valve operable in a first position to inflate or deflate the packers, in a second position to circulate fluid to spot treatment fluid at the tool, and a third position for injecting treatment fluid into the strata isolated from the remainder of the well by the packers. The tool provides a J-lock system and a time delay dashpot which cooperate to permit an operator at the well head to selectively operate the valve between the three positions solely by adjusting the weight on the support tube at the well head.
    Type: Grant
    Filed: December 9, 1988
    Date of Patent: April 3, 1990
    Assignee: Dowell Schlumberger
    Inventors: Laurent Muller, Ervin Randermann