The purpose of well workover is to complete the removal and replacement of oil tubing and other technical projects using a special workover rig and auxiliary equipment in order to restore the normal operational state of suspended wells or other oil wells that are not operating properly. Workover projects have high technical and professional requirements; hence such operations can only be carried out with large-scale workover equipment that is operated by highly experienced professionals.
I.Conventional workover technology
Since the deployment of well workover services in the Republic of Ecuador in 2009, our Company has completed workover operations on nearly 130 wells of varying sizes. Proficient operators and the solid professional skills of the personnel have led to the repeated breaking of records for the client. The minimum workover time has been less than three days, which has been met with the full approval of the client.
By virtue of excellent performance in terms of operations and management, in 2013, our company once again successfully won the bidding for two workover rigs for PAM in Ecuador. At present, workover rigs HiLong18 and HiLong28 are being used for workover operations. This signifies that the Company’s workover business has entered the field of world-class services, and our Company will see continuous improvement.
II. Coiled tubing operations
Coiled tubing equipment needs to operate under pressure and with continuous tripping. The size of the equipment is small, and the duration of operations is relatively short. The cost of such operations is also relatively low. They have advantages and application value for fast and efficient operations under underbalanced pressure conditions. They also tend to cause relatively limited damage to the formation and have a relatively low cost (owing to the simplification of the operational sequence), among other advantages. Such equipment is mainly used in the following operations: sand flushing and well washing, drilling plugs, gas lifting, liquid nitrogen injection, dewaxing, fluid displacement, acid squeezing, and for facilitating ease of testing.
Implementing innovative workover services using coiled tubing can improve the performance of oil wells and reservoirs. The scope of application of coiled tubing (CT) encompasses matrix acidizing and fracturing, elimination of filling materials and scaling, coiled tubing logging, coiled tubing perforation, nitrogen gas lift, well drilling, cementing, well fluid circulation, mechanical packer isolation, and so on.