Nitrogen lightweighted cement slurries : master’s thesis

Nakon izbušenog intervala kanala bušotine potrebno je ugraditi zaštitne cijevi te ih cementirati. Mnoge bušotine su izbušene u zonama malog slojnog tlaka i stijena male čvrstoće. Da bi u takvim uvjetima cementacija bila moguća, potrebno je smanjiti gustoću cementne kaše. To se može postići injektiranjem dušika u osnovnu cementnu kašu pri čemu nastaje pjenocementna kaša. U radu su obrađena svojstva pjenocementne kaše: gustoća, vrijeme zgušnjavanja, filtracija, reološka svojstva te svojstva cementnog kamena nastalog njezinim očvršćavanjem. Prikazani su primjeri laboratorijskih ispitivanja pjenocementne kaše te mogućnosti njezine primjene za rješavanje različitih problema u praksi. Osim navedenog, opisana je i tehnologija injektiranja pjenocementne kaše u bušotinu.After the drill bore interval, it is necessary to install casing pipes and cement them. Many wells are drilled in low pressure areas and zones of low rock strength. To be able to cement in such conditions, it is necessary to reduce the density of cement slurry. This can be achieved by injecting nitrogen into the basic cement slurry, causing a foam molding. This thesis deals with the characteristics of foaming slurry: density, thickening time, filtration, rheological properties and the properties of cement stone produced by its hardening. Examples of laboratory tests of foam slurry as well as possibilities for its application in solving various practical problems are presented. In addition to this, the injection molding technology of the foam slurry in the well is described