Squeeze Cementing Operations

Laboratory and field testing of various squeeze cementing techniques andmaterials revealed that many improvements could be made in squeeze cementingoperations. The use of a slow-pumping squeeze cementing procedure permitted thecontrol of the quantity of cement displaced into a formation and aided inobtaining a high final squeeze pressure. Field testing indicated thedesirability of obtaining high final squeeze pressures, the need for improvedformation breakdown fluids, and the necessity of controlling the pressuredifferential during testing after a squeeze job. Introduction During the past few years, squeeze cementing operations have beeninvestigated, both from the theoretical as well as the practical point of view, in an effort to arrive at some solution to the many and varied problems thatarise with this type of operation. A review of well files indicated that inmany instances, wells were being squeeze cemented four and five times before asatisfactory pressure buildup was obtained. There seemed to be considerablevariation in opinion as to the proper method of squeeze cementing, as well asdisagreement as to the proper breakdown agent, the quantity of cement thatshould be used, type retainer and length of WOC time that was necessary.Consequently, it was deemed advisable to approach this problem theoretically, field testing each idea developed in hopes of eventually arriving at a squeezecementing procedure that would give reasonable assurance of a successful jobafter one squeeze cementing operation. This investigation was, therefore, divided into two broad headings:Preliminary studies, which include boththeoretical and laboratory studies, andField investigations to determinethe proper squeeze cementing methods. Preliminary Studies Overburden Pressure Studies Squeeze cementing problems are so intimately related to the earth'soverburden pressure that solutions to them are very difficult, if notimpossible, without an understanding of the nature and magnitude of theoverburden pressures encountered at the depths of producing wells. It was thusfelt that the first approach to research on squeeze cementing should be madethrough a study of these pressures. T.P. 2795