Abstract: A method and an apparatus for injecting a fluid into a borehole. The method includes the step of injecting an injection fluid into a primary injection zone in a borehole at an injection fluid pressure. The primary injection zone is bounded by a proximal injection zone interface and a distal injection zone interface. The proximal injection zone interface and the distal injection zone interface are maintained at pressures which are substantially balanced with the injection fluid pressure. The apparatus includes a body adapted for passage through a borehole, at least four radially extendable and retractable zone interface elements spaced longitudinally along the body which when extended define at least three zones along the body, a zone interface element actuator for selectively extending and retracting the zone interface elements, and a fluid delivery system for delivering a fluid to each zone.

Abstract: A method and an apparatus for injecting a fluid into a borehole. The method includes the step of injecting an injection fluid into a primary injection zone in a borehole at an injection fluid pressure. The primary injection zone is bounded by a proximal injection zone interface and a distal injection zone interface. The proximal injection zone interface and the distal injection zone interface are maintained at pressures which are substantially balanced with the injection fluid pressure. The apparatus includes a body adapted for passage through a borehole, at least four radially extendable and retractable zone interface elements spaced longitudinally along the body which when extended define at least three zones along the body, a zone interface element actuator for selectively extending and retracting the zone interface elements, and a fluid delivery system for delivering a fluid to each zone.

Abstract: A method and an apparatus for injecting a fluid into a borehole. The method includes the step of injecting an injection fluid into a primary injection zone in a borehole at an injection fluid pressure. The primary injection zone is bounded by a proximal injection zone interface and a distal injection zone interface. The proximal injection zone interface and the distal injection zone interface are maintained at pressures which are substantially balanced with the injection fluid pressure. The apparatus includes a body adapted for passage through a borehole, at least four radially extendable and retractable zone interface elements spaced longitudinally along the body which when extended define at least three zones along the body, a zone interface element actuator for selectively extending and retracting the zone interface elements, and a fluid delivery system for delivering a fluid to each zone.

Abstract: A slug of solution, comprising a linear polymer such as polysulfone, polyethylene terephthalate or polyimide dissolved in a "good" solvent, such as morpholine, dimethylformamide m-cresol or dimethylsulfoxide, respectively, is emplaced in the near-wellbore region of an unconsolidated sand reservoir. A second slug comprising a poor solvent for the polymer, such as water or water+2-methanol is pumped into the region to contact the first slug. The linear polymer is precipitated and forms a three-dimensional network of interconnected strands extending through the fluid flow channels between the sand grains. The network functions to consolidate the sand without significantly damaging permeability. Petroleum and other fluids can then be produced without loose sand being entrained in the fluids. If necessary, this permeable network of plastic threads can be removed by re-injecting a slug of the good solvent to re-dissolve the plastic and reform the original linear polymer solution.

Abstract: A method is provided for determining the wetting preference of particulate solids, for example sand, dispersed in a multiphase liquid medium having a continuous phase and a discontinuous phase, for example a water-in-oil emulsion. A dispersion of the particulate solids and the liquid medium is passed through an electroacoustical cell and the electroacoustical signal is measured for varying solids content. If the signal remains substantially constant this indicates a wetting preference for the continuous phase, whereas if the signal decreases this indicates a wetting preference for the discontinuous phase.