ASSESSMENT OF LOST CIRCULATION DURING DRILLING OF WELLS
Abstract
The problem of lost circulation poses significant challenges to drilling operations, leading to Non-productive time (NPT) and increased costs. In order to effectively control lost circulation during drilling well construction, a holistic engineered approach is required, extending beyond the selection of appropriate lost circulation materials (LCMs).
This research. This research project aims to assess and understand the mechanics of lost circulation while providing an updated classification of LCMs and their applications. The methodology involves various elements, including borehole stability analysis, equivalent circulating density (ECD) modeling, leak-of flow path geometry considerations, and drilling fluid and LCM selection to minimize the effects on ECD.
On-site monitoring using annular pressure while drilling (APWD) and timely application of LCMs and treatments are also crucial aspects. Conventional LCMs have traditionally been categorized based on their appearances as fibrous, flaky, or granular, or a combination of these. However, the existing classification system is outdated, dating back several decades.
This project seeks to fill this gap by providing an updated classification system that encompasses both conventional and new technologies. The classification will consider the LCMs appearance, applications, chemical and physical properties, and categorize them as either corrective or preventive approaches.
Corrective treatments can be applied after the occurrence of lost circulation, while preventive techniques are deployed proactively before encountering lost circulation zones. Furthermore, this research project highlights the latest developments in LCMs and treatments, presenting a comprehensive summary of the currently available LCMs, alternative approaches, and their respective applications.
By examining and evaluating the effectiveness of these materials and treatments, the aim is to provide valuable insights into their practical implementation and performance during drilling operations.
Research summary
In order to effectively control lost circulation during drilling well construction, a holistic engineered approach is required, extending beyond the selection of appropriate lost circulation materials (LCMs). The methodology involves various elements, including borehole stability analysis, equivalent circulating density (ECD) modeling, leak-of flow path geometry considerations, and drilling fluid and LCM selection to minimize the effects on ECD. Furthermore, this research project highlights the latest developments in LCMs and treatments, presenting a comprehensive summary of the currently available LCMs, alternative approaches, and their respective applications. By examining and evaluating the effectiveness of these materials and treatments, the aim is to provide valuable insights into their practical implementation and performance during drilling operations.