【摘要】 预胶化淀粉（PGS）具有强降失水性能。用PGS配制的饱和盐水泥浆性能稳定,在钻井过程中形成的泥皮薄而致密。这种泥浆能抑制粘土水化膨胀,防止井壁坍塌,而且抗Ca²⁺、Mg²⁺污染的效果好。在生产试验中发现,PGS饱和盐水泥浆尤其适用于钻进高盐高钙地层,如岩盐层、石膏层、芒硝层。维护这种泥浆的关键是维持盐饱和、控制无用固相含量、净化泥浆、保持pH值在9～11。PGS饱和盐水泥浆配方简单,成本低廉,使用方便,在生产中具有广泛的推广应用价值。更多还原

【Abstract】 The Pregelatinized Starch (PGS) is of good property of reducing the loss of water. Muds made of clay, salt-saturated water and PGS can form a thin and dense mud cover upon the well wall during drilling. Further, the PGS salt-saturated mud can restrain the clay within the well wall from absorbing water and swelling. So that it can prevent the well wall from collapsing. The field tests show that this kind of muds especially suits to drilling the high salt and high calcium strata, such as salt, gypsum and glauberite formations. The important matters for the PGS muds are to keep the salt saturated, to restrict the useless solid content and to maintain the pH of 9 to 11. The PGS salt-saturated mud is of low cost, easy to prepare and to use in drilling operation.更多还原