Practice of Optimal Drilling and Completion in Oilfield E in the Deepwater of West Africa

During the drilling and completion of the first developed Oilfield A in the deepwater Block O of West Africa, many kinds of complex accidents were encountered, such as machine failure, string jamming, and downhole tool failure and so on. The production rate was only 74.6%, and the average single-well drilling and completion period was 82.9 d. In order to improve the efficiency of drilling and completion operations, shorten the non-productive operation time, a series of excellent and fast measures were adopted in the design and operation of Oilfield E which was subsequently developed in the same block. Adopting a standardized scheme design to help the accumulation of field operation experience. Before the string enters the well, the full-process simulation calculation shall be carried out to identify risks in advance and reasonably reduce the frequency of operations such as pipe scraping and drifting. Tap the potential of off-line operation without occupying pre-installed pipelines and tools at the wellhead. Using multifunctional ships with lower daily fees for oil tree installation and operations such as cleanup, thus saving the operation time of drilling ships. Fully cleaning the well before completion is to ensure the cleanliness of the wellbore which is helpful to reduce the rate of downhole accidents. Moving drilling ship between wells using the suspended riser mode is to save time. Through the above measures, the average drilling and completion period was 40.9 d/well, and the fastest well took only 20.9 d, which created the world's fastest record in deepwater drilling and completion. Summarizing the operating experience of Oilfield E is helpful to provide reference for the subsequent development of deepwater oilfields.