The Study And Application Of Anti-blockage Coring Technology

Core barrel blockage usually occurs in the unconsolidated and broken sand formation coring, if this is not detected in time then the core will be worn out easily, and the data will be lost. Based on this, This article, firstly, investigates on current situation and trends in development of the unconsolidated and broken formation coring technique at home and abroad. Then, Analyzes of influencing factors of the unconsolidated and broken formation coring recovery rate. At last, based on the lithological features of the unconsolidated and broken sand formation, this paper author conducts a comprehensive research.Successfully developed coring tool in unconsolidated formation, perfecting several single coring techniques. Includes: ball hanging coring technology, totally enclosed core catcher coring technology and guiding sleeve coring technology, which reached domestic advanced level, especially, the guiding sleeve coring technology filled a domestic gap in this field .Successfully developed coring tool in broken formation, core monitoring device and plugging removal core barrel have been developed. This technology not only increasing coring recovery rate, improving length of core per barrel, saving time efficiency of drilling, has achieved international advanced level.Composite Materials and aluminum alloy core barrel have been developed, which makes broken formation conformal coring possible, and has achieved international advanced level.Several different structure, suiting to different formation PDC core bits have been developed , which obtained a favourable effect by field experiment and improved the coring drilling speed and core recovery rate.A set of new coring technology of unconsolidated and broken formation has been formed.The unconsolidated and broken formation coring technology studied by this paper, has the great significance in improving recovery factor of old oilfields and strategic adjustment of oilfield development.