A Simplified Cementing Technique for Recompletion Operations

Abstract

Published in Petroleum Transactions, AIME, Volume 201, 1954, pages 27–33. Abstract Simplified equipment and techniques have been developed to permit cementing a completion interval in a well and recompleting higher, lower, or at the same depth in such a manner as to:Eliminate the need for a conventional drilling or workover rig.Eliminate mud and other cement contaminants which have long interferred with ideal cementing.Eliminate need for drilling out cement.Provide a more satisfactory recompletion.Provide a more economical recompletion. This technique involves the use of a small-diameter, lightweight, tubing extension which is run on a wireline and set in a landing nipple previously installed in the tubing string. Low squeeze pressure and small cement volumes, with their attendant cost reduction, are successfully used when wells are completed and reworked with salt water or other penetrating fluids. Relatively low-water-loss cement is an integral component of the technique which provides that excess cement be reverse-circulated from the well to leave the casing void of cement when recompleting lower or in the same interval. Substantial cost reductions ate realized by using the simplified or low-pressure cementing technique, and the ratio of successful squeeze-cement operations has been increased. Introduction Squeeze-cementing or recementing is the act of filling a channel behind casing or filling holes purposely placed in the casing. To obtain a satisfactory squeeze-cement job, it is necessary only to fill the channel or the perforation holes with a cement filter cake and to allow it to harden in that position. In the past, the presence of mud in a well has been considered the chief deterrent to obtaining a good cement bond and satisfactory cement job; however, late developments in squeeze-cementing have made it possible to eliminate cement contamination or interference. Since it is possible to form a cement filter cake with a small pressure differential, squeeze-cementing with high pressures may not be necessary in most cases.