Dongfang 1-1 Gas Field Formate Drilling Fluid Integration Of Technology Research

Drilling and completion fluid integrated technology" is a great improvement of working fluid technology in oil and gas wells at the end of last century, and is the inexorable trend of following development of working fluid technology too.As a new-type drilling and completion fluid system just developing in recent years, formate brines system is approved by petroleum industry of the world at present and gets recognition of it. Because of formate brines system's superior process performance and characteristic of environmental protection, formate brines system is regard as the most progressive drilling and completion fluid integrated system.East 1-1 gas field is located in the western part of the South China Sea. It has some characteristics as following: the gas reservoir is buried shallow, the formation pressure coefficient is relatively low, the dip angle of stratum is small, the salinity of formation brine is relatively high and the formation lithology of non-reservoir is single. Combining with the characteristics of the East 1-1 gas field, based on the basic theoretical research on formate brines at home and abroad and depending on a series of proper treating agent developed in SWPI, by large experiment studies, this paper optimizes formate brines drilling and completion fluid integrated system which is an environment-protecting, low-damage system and suits the characteristics of East 1-1 gas field. Moreover, this paper studies the matching protecting reservoir technologies such as film-forming and plugging technology, eliminating mudcake technology.Besides, this paper adopts weight-loss method to study the corrosion law of formate brines drilling and completion fluid against metal materials. The result shows that formate brines drilling and completion fluid system has a low corrosion rate against metal materials and needn't add any retardant under alkaline and CO2-content terms.