But they lie far underground, below deep waters and a thick, drill-foiling layer of salt. 但是这些油田埋藏在很深的地方,不仅有很深的海水,还有一层厚厚的难以钻透的盐层阻隔。
It has been proved that dual com bined casing used in salt rock and other strata are reliable for preventing the casing from collapsing. 实践表明,双层组合套管在盐层段和其它特殊层段的应用,对预防套管损坏是切实可行的。