ANALYSIS OF CEMENT SLURRY PERFORMANCE DURING REPAIR–ISOLATION OPERATIONS IN PRODUCING WELLS: RETARDING ADDITIVES

Relevance of the Topic-Maintaining the structural integrity of wells during the exploitation of oil and gas fields is a critical factor for ensuring stable and safe production. As the operational lifetime of wells increases, the development of interlayer hydraulic communication, degradation of functional well components, and uncontrolled fluid migration may occur, leading to serious technical and economic challenges. Repair–isolation operations and cementing technologies play a key role in mitigating these issues, particularly in complex geological settings and under high-pressure and high-temperature conditions, where scientifically justified technology selection is especially important. Problem Statement-Practical experience demonstrates that repair–isolation and cementing operations performed in producing wells do not always deliver the expected technical performance. The main reasons include inappropriate material selection, insufficient consideration of geological and reservoir characteristics, and inadequate optimization of technological processes. Consequently, the limited effectiveness of conventional methods across diverse operating conditions necessitates the investigation of more efficient and improved approaches. Research Objective-The objective of this study is to assess the technical and economic efficiency of mechanical, chemical, and combined repair–isolation technologies, as well as various well cementing systems applied in producing wells. Scientific Novelty and Contribution-As a result of the study, a comparative evaluation of repair–isolation and cementing technologies has been carried out, and the key factors influencing their effectiveness have been identified. The behavior of cement compositions used under high-pressure and high-temperature conditions has been analyzed, and techno-economic criteria for selecting optimal technologies have been substantiated. The obtained results are of scientific and practical significance, contributing to improved well isolation quality and enhanced operational reliability. Keywords: producing wells, well cementing, repair–isolation operations, cement slurry, setting kinetics, temperature effect, retarding additives, well isolation.