Technological efficiency of applying viscoelastic systems for temporary blocking of productive reservoir when completing wells under conditions of abnormally low formation pressures

Abstract

The article examines the technical and economic aspects of well killing under conditions of abnormal low reservoir pressure (ALRP). The possibility of joint use of compositions for temporary blocking of a productive formation, having different functional abilities to plug fluid-conducting channels, has been studied. Requirements for blocking fluids (BF) for killing during repair works in wells with excess ALRP have been formulated. The results of research and technical solutions in the field of development of viscoelastic systems for temporary blocking of productive formations in wells in conditions above the ALRP are presented. The results of laboratory and bench studies on the development of a gel-forming destructuring polymer-based biosol and fillers are presented. The advantage of using a destructurable biological fluid for temporary blocking of a productive formation in conditions above the maximum pressure limit using chemical reagents belonging to the following groups: polymers, salts, surfactants, acids, alkalis and fillers has been analyzed. The results of determining the mechanical properties of the resulting BF gel are presented. A gel-forming composition has been proposed that has high blocking properties and an optimal formulation of an alkaline destructor that ensures the destruction of the gel based on gammaxan. Formulations of viscoelastic destructurable fluids for killing wells in conditions exceeding the ALRP have been recommended for practical use. Keywords: well; bottomhole formation zone; blocking; blocking fluids; viscoelastic compositions; destructuring; ALRP.