Open AccessAnalysis of the Performance Improvement Effect of Combined Packing for Oil and Gas Well Packer
Author(s) -
Huifeng Liu,
Wei Zhang,
Yinping Cao,
Yihua Dou
Publication year - 2020
Publication title -
iop conference series. earth and environmental science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.179
H-Index - 26
eISSN - 1755-1307
pISSN - 1755-1315
DOI - 10.1088/1755-1315/514/2/022017
Subject(s) - casing , seal (emblem) , finite element method , compression (physics) , expansion ratio , materials science , geotechnical engineering , structural engineering , engineering , composite material , petroleum engineering , art , visual arts
Packer is a commonly used downhole tool for oil and gas wells. In order to understand the working performance of combined packing, a finite element analysis is performed on the double expansion-compression-expansion combined seal packers to find the effect of combined seal. Taking packers sealed in casing with a diameter of 114.3mm and a wall thickness of 12.7mm as an example, finite element models are established for double expansion and expansion-compression combined seal packers respectively. By applying packer-setting pressure to the finite element models and processing the strain-stress data resulting from finite element analyses, the distribution rules of packing stress and contact pressure between the packing and the inner casing wall for different combined seal packers are obtained. The working performance of the single expansion seal packer and the double expansion and expansion-compression combined seal packers is compared and analyzed. According to the results of finite element analyses, both double expansion combined seal and expansion-compression combined packings can be in effective contact with the casing under a packer-setting pressure of 15MPa, and the contact pressure between the combined seal packing and the inner casing wall is larger than that of a single seal packing. The combined seal packer therefore can actually improve the sealing and packoff effect of the packer. The expansion-compression combined seal has the highest pressure bearing capacity, which is 50% higher than that of the single expansion packer. The lower packing of the double expansion combined packer and the expansion packing of the expansion-compression combined seal packers should be appropriately strengthened and thickened to improve the packing performance of the combined seal packer. The results of contrastive analysis reveal the improvement effect of the sealing and packoff performance of the combined seal packers, which can be used as a reference for the improved design of such packer.