PRACTICE AND DISCUSSION ON SUPPORTING THE HOLE WALLS AND PLUGGING THE LEAKY ZONES WITH COMMON PORTLAND CEMENT

Using cement slurry to support the hole walls and plug the leaky zones is one of the effective ways in drilling construction to deal with the troublesome zones. Slurry of the common portland cement can be of the same functions of many kinds of special cement by adding additives. So using additives properly can obtain the better technical and economic effect in substituting the common cements for the special ones to deal with the troublesome zones.