Research progress and development trend of high-density completion fluids for deep water oil and gas drilling

With the development of the petroleum industry, offshore oil and gas exploration and development are gradually shifting from shallow sea areas to deep sea areas, and the requirements for completion fluid density are also developing from low to high to ultra-high or even extra high. However, as the formation temperature and pressure increase, new challenges and difficulties in controlling completion fluid performance are faced. Therefore, there is an urgent need for a new type of high-performance completion fluid for deep water reservoirs, which is of great significance for ensuring the efficiency, safety and environmental protection of deep water completion operations. This paper starts from the existing problems and performance requirements of deep water high-density completion fluids, and provides a detailed introduction to the types and functions of additives required for completion fluids. It also systematically reviews and summarizes the different types of deep water high-density completion fluid systems that have emerged in recent years. High-density completion fluids face damage to the formation caused by solid phase completion fluids, while nonsolid phase completion fluids have problems such as high cost, strong corrosiveness and marine pollution. No completion fluids have been found that can simultaneously meet the multiple characteristics of high density, harmless reservoir, high-temperature resistance, environmental friendliness, nontoxicity and high economic benefits. To meet the performance requirements of deep water high-density completion fluids, the completion fluids will focus on improving adaptability in extreme environments, enhancing environmental performance and solving complex formation leakage problems. Through breakthroughs in key materials and technologies, innovation in environmentally friendly products, and the use of big data, cloud computing, artificial intelligence and other technologies to promote the development of intelligent completion fluids technologies is provided for the exploration and development of deep water and deep oil and gas resources.