| 摘要 |
<p>A non-damaging well drilling fluid contains a polysaccharide, a lignosulfonate, chrome sulfate, a pH modifier and, preferably, graded calcium carbonate and starch. The fluid is effective to seal off the well bore essentially immediately and is non-damaging in that it causes little permanent plugging of the formation by loss of the drilling fluid solids to the formation.</p> |
