This invention relates to a method of using an impression element in a well to determine the effective connection to permeability of a fluid flow opening in a tubular member positioned under liquid in the well. More particularly this invention relates to using an inflatable impression packer having an inflatable sleeve containing an impression element to contact a liquid filled tubular member adjacent a fluid flow opening therein to determine whether or not the fluid flow opening is connected for effective fluid flow to or from the formation penetrated by the well.
In well operations and in particular oil well operations it is common practice to place a tubular member such as a well liner or casing in the well adjacent a producing formation. The tubular member is provided with relatively small fluid flow openings which are designed to permit flow of fluids from the formation into the well or from the well into the formation without permitting said or other fines to enter the well. The flow openings in the tubular member may be slots precut in the tubular member before it is positioned in the well or the flow openings may be perforations made in a tubular member after it has been run in the well. The tubular member is usually cemented into place in the well adjacent a desired formation. It is often necessary to know if the flow opening, for example, a slot or a perforation, even though actually existing in the tubular member actually permits flow of fluids to or from the formation. Stated simply, is the flow opening effectively connected to formation permeability? Thus, even though a flow opening may appear to exist in the tubular member effective connection to the formation may be prevented by cement, formation damage or ineffective gun or jet perforation. The present invention is directed to determining whether or not the flow opening is connected to permeability. Further, the present invention is directed to determining the relative permeability to liquid flow through the formation behind the flow opening.