A tool and method are disclosed for injecting various treatment fluids into a formation surrounding an underground borehole. The tool comprises at least three axially spaced swab assemblies which define at least two annular spaces between the tool body and the wellbore. In use the tool is moved through the wellbore whilst a first treatment fluid such as a sand consolidation agent or production stimulation chemical, is pumped via a first annular space into the formation and a second treatment fluid, such as an overflush fluid, is pumped via a second annular space into the formation. The tool allows accurate and continuous injection of various treatment fluids over long intervals into the formation without requiring cycling to new fluids.

Apparatus and method of injecting treatment fluids into a formation surrounding an underground borehole

The method and apparatus for treating multiple production zones includes a completion string having a plurality of sets of tools including a closing sleeve, indicator collar, and production screens with an isolation packer disposed between each adjacent set. An inner service tool is disposed within the outer completion string and includes an upper portion with a crossover tool and a lower portion with a closing sleeve shifter and a weight-down collet with the upper and lower portions being connected. The apparatus is assembled by assembling an initial length of the outer completion string which does not includes any of the closing sleeves or indicator collars. After the initial length is assembled, the lower portion of the service tool with the closing sleeve shifter and weight-down collet are assembled and inserted into the initial length of completion string. The remainder of the completion string is then assembled with all closing sleeves in the closed position. The upper portion of the service tool is then assembled and stabbed and connected into the lower portion. As multiple production zones are treated, the inner service tool is raised and then lowered opening a closing sleeve and setting weight on the indicator collar. A predetermined amount of weight is then maintained during the operation to ensure that the crossover tool is positioned adjacent the opened closing sleeve. The production zone then may be treated in the weight-down position.

Method and apparatus for treating multiple production zones

An isolation gravel packer includes a housing which has a stinger receptacle disposed therein. The stinger receptacle has an open upper end and an inner cylindrical seal bore. The inner cylindrical seal bore sealingly receives a concentric inner tubing string therein for delivering a treatment fluid thereto. A treatment fluid passage is disposed laterally through the housing for communicating an interior of the stinger receptacle at an elevation below the seal bore with the well zone to be treated. First and second external seals are disposed on an exterior of the housing above and below the treatment fluid passage, respectively, for sealing between the housing and a liner bore. The housing also includes a combination bypass passage and return fluid passage disposed therein which is isolated from the treatment fluid passage. Treatment fluid is flowed from a surface location down through the concentric inner tubing string, then through the treatment fluid passage to the well zone. Return fluid flows from the well zone upward through the combination bypass passage and return fluid passage, then through an annulus between an outer tubing string and the concentric inner tubing string to the surface location.

Isolation gravel packer

Pore-scale analysis of formation damage in Bentheimer sandstone with in-situ NMR and micro-computed tomography experiments

Method and apparatus for fracturing different levels of a completion interval in a well. A workstring lowers a fracturing string which, in turn, is comprised of a base pipe which is blank except for perforated sections spaced along its length. Screen may be provided over said sections to block the flow of sand into the base pipe. An alternate flow path (e.g. shunt tubes) extends along the base pipe and has one or more outlets spaced along its length. A slurry is flowed into the annulus surrounding the fracturing string. As liquid is lost from the slurry, sand from the slurry will form bridges at said perforated sections thereby isolating portions of the annulus. Slurry then flows through the shunts tube(s) and out into the isolated portions to fracture the different levels in the completion interval.

Fracturing different levels within a completion interval of a well

An improved gravel-packing tool assembly with a baffled stinger pipe for gravel-packing a perforate liner having substantially the same internal diameter as the casing string extending from the perforate liner to the earth surface. A perforate nipple and a swab cup are provided between the check valve and the baffled stinger pipe of the tool assembly to allow drainage of the annulus above the tool assembly through the stinger pipe to thereby avoid swabbing the well as the tool is retrieved from the well.

George P. Maly

Papers

Gravel-packing tool assembly

New Gravel Pack Tool for Improving Pack Placement

Thin-Section and Permeability Studies Call For Smaller Gravels in Gravel Packing