Wellbore fluid flow rates and other fluid properties may be measured by a tool which is insertable in the wellbore on the end of a tubing string and includes an instrument section and an inflatable packer disposed on the tool for inflation by conducting pressure fluid down the tubing string to the packer....http://www.google.co.uk/patents/US5018574?utm_source=gb-gplus-sharePatent US5018574 - Tubing conveyed wellbore fluid flow measurement apparatus
