Design and Selection of Cross Section of Expandable Convoluted Tube for Geological Exploration

Abstract:

Expandable profile liner (EPL) is a new drilling technology of hole wall stability maintenance, the round tube is pressed to be special cross-section tube, lowering into the hole, then expanding to circular tube. Aiming at the requirements of geological exploration industry, a set of design theory of expandable profile liner section shape is put forward in this paper, the related steps and details of the design are systematically described, and design diagrams of expandable profile liner section shape of 6 different models and sizes were presented. On this basis, comparative analysis on the different designed section shapes are made by using ANSYS14.0 numerical simulation software, 3 principles for expandable profile liner selection are obtained: plum blossom with six petals is the best section shape; the crest & troughs radius dimensions of the designed section and the radian should be as close as possible; and the wall thickness should be as small as possible under the prerequisite of satisfying the requirements of wall protection pressure.

Key words:drilling; expandable profile liner; cross section design; shape selection; numerical simulation