System and method for removing sludge from a storage tank

A method for removing a hydrocarbon sludge from a crude oil storage container, the storage container having an access opening through a side of the container, through which the bottom of the container can be reached, comprising the steps of:

• providing a concentric pipe member having an inner pipe surrounded by an outer pipe, said inner pipe being generally spaced from said outer pipe to create a generally annular open region therebetween;
• supplying a working fluid communicating with said inner pipe, said supply of working fluid being provided to said inner pipe under positive pressure;
• said inner pipe having a distal end;
• providing a nozzle releasably attachable to said distal end of said inner pipe;
• said outer pipe having at least one distal opening:
• supplying a source of negative pressure to said outer pipe to remove material from the container;
• inserting a length of said concentric pipe member including said inner pipe distal end and said outer pipe distal opening through said access opening into said container;
• providing a platform carrying a portion of said concentric pipe member, said platform including a pipe drive mechanism for moving said concentric pipe in a horizontal direction generally along a long axis of said concentric pipe, said pipe drive mechanism including at least one rotary element engaging an exterior wall of said outer pipe and a drive motor for driving said rotary element, said platform further including a platform drive mechanism for adjusting the height of said concentric pipe in a vertical direction;
• forcing pressurized working fluid through said inner pipe and out said nozzle in a manner to agitate and fluidize the sludge;
• withdrawing fluidized sludge through said opening of said outer pipe;
• and
• moving said concentric pipe using each said drive mechanism variously to effect removal of sludge from the container.